Category Archives: Nature

Declining English wetland ‘is poor advert for UK’

A declining English wetland will embarrass the UK government at November’s UN climate conference, campaigners say.

LONDON, 23 March, 2021− The area around Chichester Harbour on Britain’s south coast overlooks the English Channel. Famed as a beauty spot, it is a draw for holiday-makers from the crowded towns and cities of southern Britain. It is also one of the UK’s key habitats for many bird species and for endangered mammals such as water voles. But the condition of this declining English wetland is stirring concern.

Coastal wetlands are not only important for wildlife and tourism, conservationists argue. They are one of nature’s most efficient ecosystems for absorbing carbon dioxide, and among the best forms of coastal protection, increasingly recognised for making low-lying areas more resilient and adaptable to sea level rise.

A report by researchers at the University of Cambridge, UK, published in the journal Nature Sustainability, spells out how the value of natural wetlands far exceeds that of managed or farmed land.

The low-lying coastal plain surrounding the ancient Roman city of Chichester is one of the UK areas most vulnerable to sea level rise, increased storminess and intense rainfall.

“The sad plight of Chichester’s wetlands is an embarrassment for the government as it prepares to host COP-26, the UN’s annual climate conference”

It has done pioneering work in climate change mitigation and adaptation, including protecting the Medmerry Reserve wetlands, Europe’s largest coastal realignment scheme  when it opened in 2013. The Harbour contains the largest salt marsh on the south coast, but nearly half of it has been lost since 1970.

But now local people charge the government with neglecting their efforts to increase the area’s resilience. Libby Alexander founded the Save our South Coast Alliance (SOSCA). She says: “The sad plight of Chichester’s wetlands is an embarrassment for the government as it prepares to host COP-26, the UN’s annual climate conference, due to be held this year in Glasgow in November.” Nor is the physical condition of the Harbour her only concern.

“The government continues to preach to us and the rest of the world about climate change and the environment”, she says, “but practices an entirely different agenda. It is driving forward a building programme which is endangering the future of some of the country’s most important wetlands.”

Unfavourable condition

A report in the Guardian newspaper described the fear of many local people at “the threat of ‘rural sprawl’ creating new landscapes … the ‘suburbanisation’ of the countryside”, resulting from the government’s plans for changes to England’s planning system.

SOSCA says the threats it faces from the government’s drive for more housebuilding in south-east England include 12,650 unnecessary new homes across the coastal plain with the strong possibility of many more − “the wrong houses in the wrong places” − which will inevitably lead to extensive and irreversible damage through pollution and flooding. It says Chichester is being forced by the government to build far more new houses than it can safely accommodate.

Residents say a real threat is the untreated sewage that is pumped into the harbour, for which the local water company, Southern Water, has been penalised. It was fined £126 million in 2019 for spills of waste water into the environment from its sewage plants and for deliberately misreporting its performance. A great number of these discharges went into Chichester Harbour. The Environment Agency is reported to have launched a criminal investigation into the case.

Chichester Harbour Trust says not enough is being done to improve water quality in the Harbour. Its chairman, John Nelson, said: “We all need to force the regulators to take immediate action before we have an environmental and public health catastrophe.”

In January this year the Chichester Observer reported that over the 2020 Christmas period there were uninterrupted sewage discharges into Chichester Harbour for six days. Mr Nelson said: “Given Southern Water’s record over the Christmas period the time has come to implement radical change. The Trust is calling on the regulatory body Ofwat to use its legislative powers to put Southern Water into special administration in order to avoid an environmental catastrophe.”

Natural England is the government’s official environment adviser. It has published a new and authoritative report which describes Chichester Harbour, globally important for migratory birds, as now being in an “unfavourable and declining” condition, because of increasing development and rising sea levels.

Serious climate change adaptation and mitigation needs to be factored into the planning process immediately, says SOSCA. “Ironically, the UK government is promoting global coastal wetland conservation through its Blue Forests Initiative but failing to support the efforts of its own citizens”, said Libby Alexander. − Climate News Network

* * * * * * *

Dr Carolyn Cobbold is a Research Fellow at the University of Cambridge. A former journalist, she has been writing about climate change issues since the mid-1980s. Twitter: @DrCobbold

A declining English wetland will embarrass the UK government at November’s UN climate conference, campaigners say.

LONDON, 23 March, 2021− The area around Chichester Harbour on Britain’s south coast overlooks the English Channel. Famed as a beauty spot, it is a draw for holiday-makers from the crowded towns and cities of southern Britain. It is also one of the UK’s key habitats for many bird species and for endangered mammals such as water voles. But the condition of this declining English wetland is stirring concern.

Coastal wetlands are not only important for wildlife and tourism, conservationists argue. They are one of nature’s most efficient ecosystems for absorbing carbon dioxide, and among the best forms of coastal protection, increasingly recognised for making low-lying areas more resilient and adaptable to sea level rise.

A report by researchers at the University of Cambridge, UK, published in the journal Nature Sustainability, spells out how the value of natural wetlands far exceeds that of managed or farmed land.

The low-lying coastal plain surrounding the ancient Roman city of Chichester is one of the UK areas most vulnerable to sea level rise, increased storminess and intense rainfall.

“The sad plight of Chichester’s wetlands is an embarrassment for the government as it prepares to host COP-26, the UN’s annual climate conference”

It has done pioneering work in climate change mitigation and adaptation, including protecting the Medmerry Reserve wetlands, Europe’s largest coastal realignment scheme  when it opened in 2013. The Harbour contains the largest salt marsh on the south coast, but nearly half of it has been lost since 1970.

But now local people charge the government with neglecting their efforts to increase the area’s resilience. Libby Alexander founded the Save our South Coast Alliance (SOSCA). She says: “The sad plight of Chichester’s wetlands is an embarrassment for the government as it prepares to host COP-26, the UN’s annual climate conference, due to be held this year in Glasgow in November.” Nor is the physical condition of the Harbour her only concern.

“The government continues to preach to us and the rest of the world about climate change and the environment”, she says, “but practices an entirely different agenda. It is driving forward a building programme which is endangering the future of some of the country’s most important wetlands.”

Unfavourable condition

A report in the Guardian newspaper described the fear of many local people at “the threat of ‘rural sprawl’ creating new landscapes … the ‘suburbanisation’ of the countryside”, resulting from the government’s plans for changes to England’s planning system.

SOSCA says the threats it faces from the government’s drive for more housebuilding in south-east England include 12,650 unnecessary new homes across the coastal plain with the strong possibility of many more − “the wrong houses in the wrong places” − which will inevitably lead to extensive and irreversible damage through pollution and flooding. It says Chichester is being forced by the government to build far more new houses than it can safely accommodate.

Residents say a real threat is the untreated sewage that is pumped into the harbour, for which the local water company, Southern Water, has been penalised. It was fined £126 million in 2019 for spills of waste water into the environment from its sewage plants and for deliberately misreporting its performance. A great number of these discharges went into Chichester Harbour. The Environment Agency is reported to have launched a criminal investigation into the case.

Chichester Harbour Trust says not enough is being done to improve water quality in the Harbour. Its chairman, John Nelson, said: “We all need to force the regulators to take immediate action before we have an environmental and public health catastrophe.”

In January this year the Chichester Observer reported that over the 2020 Christmas period there were uninterrupted sewage discharges into Chichester Harbour for six days. Mr Nelson said: “Given Southern Water’s record over the Christmas period the time has come to implement radical change. The Trust is calling on the regulatory body Ofwat to use its legislative powers to put Southern Water into special administration in order to avoid an environmental catastrophe.”

Natural England is the government’s official environment adviser. It has published a new and authoritative report which describes Chichester Harbour, globally important for migratory birds, as now being in an “unfavourable and declining” condition, because of increasing development and rising sea levels.

Serious climate change adaptation and mitigation needs to be factored into the planning process immediately, says SOSCA. “Ironically, the UK government is promoting global coastal wetland conservation through its Blue Forests Initiative but failing to support the efforts of its own citizens”, said Libby Alexander. − Climate News Network

* * * * * * *

Dr Carolyn Cobbold is a Research Fellow at the University of Cambridge. A former journalist, she has been writing about climate change issues since the mid-1980s. Twitter: @DrCobbold

Nature left alone offers more than if we exploit it

Save nature, save money. It’s a simple argument. Wilderness cleared and ploughed offers us less than nature left alone.

LONDON, 19 March, 2021 − British scientists have once again made the commercial case for conserving wilderness. They have demonstrated that in its pristine state − mangrove swamps, wetlands, savannahs, forests and so on − nature left alone is of more value to humankind than as exploited real estate.

This argument has been made already, and more than once. But this time the researchers can provide the detail for their argument: they report in the journal Nature Sustainability that they had devised an accounting methodology to test such arguments, and then applied this in 24 selected sites around the planet.

Some of the value would be in intangibles such as providing a shelter for the wild things and wild plants; some of it would be measurable. For instance, if the damage inherent in carbon spilled into the atmosphere through habitat destruction or fossil fuel combustion presents an overall cost to society of $31 a tonne − and this is a conservative estimate − then almost three quarters of the sample sites have greater value simply as natural habitats.

And that includes 100% of all forests. If that greenhouse gas carbon was valued at a paltry $5 a tonne, almost two thirds of the sites would still be, over a 50-year period, a better investment left untouched.

“At current levels of habitat conversion, conserving and restoring sites typically benefits human prosperity”

But what climate scientists now call “natural capital” − the invisible services  provided by nature in crop pollination, water filtration and planetary air conditioning − is of measurable commercial value even without the vital role of carbon sink. Of the 24 sites, 42% would still be worth more in their natural form than converted to cropland.

“Stemming biodiversity loss is a vital goal in itself, but nature also fundamentally underpins human wellbeing,” said Richard Bradbury, of the University of Cambridge. “We need nature-related financial disclosure, and incentives for nature-focused land management, whether through taxes and regulation or subsidies for ecosystem services.”

And his Cambridge co-author Andrew Balmford said: “Current rates of habitat conversion are driving a species extinction crisis unlike anything in human history. Even if you are only interested in dollars and cents, we can see that conserving and restoring nature is now very often the best bet for human prosperity.”

In fact the researchers made their conclusions based on 62 sites, but concentrated on 24 simply because in these cases they had the most reliable information about the potential commercial value of their sample against which to measure the value of restoring it, or protecting it, or both.

Valuable saltmarsh

If Nepal’s Shivapuri-Nagarjun National Park was turned from forest to farmland, investors would gain immediate capital from the value of the timber, and a longer-term income from crops. But the loss of carbon storage would be 60%, and the damage to water quality would be 88%, and Nepal would be $11m worse off.

Even a saltmarsh near Preston in the United Kingdom proved to be worth $2000 a hectare in terms of its value in mitigating carbon emissions: no income from crops or forage grazing could match that.

That left 38 sites for which the economic data was less certain: even in these cases, the “goods and services” delivered by the site in its natural state was, for two thirds of them, of more value to humankind as a whole than calculated exploitation by a few.

“Our findings indicate that, at current levels of habitat conversion, conserving and restoring sites typically benefits human prosperity,” the authors say. − Climate News Network

Save nature, save money. It’s a simple argument. Wilderness cleared and ploughed offers us less than nature left alone.

LONDON, 19 March, 2021 − British scientists have once again made the commercial case for conserving wilderness. They have demonstrated that in its pristine state − mangrove swamps, wetlands, savannahs, forests and so on − nature left alone is of more value to humankind than as exploited real estate.

This argument has been made already, and more than once. But this time the researchers can provide the detail for their argument: they report in the journal Nature Sustainability that they had devised an accounting methodology to test such arguments, and then applied this in 24 selected sites around the planet.

Some of the value would be in intangibles such as providing a shelter for the wild things and wild plants; some of it would be measurable. For instance, if the damage inherent in carbon spilled into the atmosphere through habitat destruction or fossil fuel combustion presents an overall cost to society of $31 a tonne − and this is a conservative estimate − then almost three quarters of the sample sites have greater value simply as natural habitats.

And that includes 100% of all forests. If that greenhouse gas carbon was valued at a paltry $5 a tonne, almost two thirds of the sites would still be, over a 50-year period, a better investment left untouched.

“At current levels of habitat conversion, conserving and restoring sites typically benefits human prosperity”

But what climate scientists now call “natural capital” − the invisible services  provided by nature in crop pollination, water filtration and planetary air conditioning − is of measurable commercial value even without the vital role of carbon sink. Of the 24 sites, 42% would still be worth more in their natural form than converted to cropland.

“Stemming biodiversity loss is a vital goal in itself, but nature also fundamentally underpins human wellbeing,” said Richard Bradbury, of the University of Cambridge. “We need nature-related financial disclosure, and incentives for nature-focused land management, whether through taxes and regulation or subsidies for ecosystem services.”

And his Cambridge co-author Andrew Balmford said: “Current rates of habitat conversion are driving a species extinction crisis unlike anything in human history. Even if you are only interested in dollars and cents, we can see that conserving and restoring nature is now very often the best bet for human prosperity.”

In fact the researchers made their conclusions based on 62 sites, but concentrated on 24 simply because in these cases they had the most reliable information about the potential commercial value of their sample against which to measure the value of restoring it, or protecting it, or both.

Valuable saltmarsh

If Nepal’s Shivapuri-Nagarjun National Park was turned from forest to farmland, investors would gain immediate capital from the value of the timber, and a longer-term income from crops. But the loss of carbon storage would be 60%, and the damage to water quality would be 88%, and Nepal would be $11m worse off.

Even a saltmarsh near Preston in the United Kingdom proved to be worth $2000 a hectare in terms of its value in mitigating carbon emissions: no income from crops or forage grazing could match that.

That left 38 sites for which the economic data was less certain: even in these cases, the “goods and services” delivered by the site in its natural state was, for two thirds of them, of more value to humankind as a whole than calculated exploitation by a few.

“Our findings indicate that, at current levels of habitat conversion, conserving and restoring sites typically benefits human prosperity,” the authors say. − Climate News Network

Europe has grown drier over the last two millennia

Global heating may be to blame for the fact that Europe has grown drier over the last 2,000 years to a new high in 2015.

LONDON, 17 March, 2021 − Europe has grown drier, an outcome shown by the continent’s last five summers, which have been marked by drought that has no parallel in the last two millennia.

Researchers studied two kinds of evidence delivered by 27,000 measurements taken from 21 living oak trees and 126 samples from ancient beams and rafters, to piece together a precise picture of the climate of Germany, Switzerland and the Czech Republic over the last 2,110 years.

They report, after 2015, that drought conditions intensified suddenly, in ways that were beyond anything over that entire 2000-year tract of time. And, they add, “this hydroclimatic anomaly is probably caused by anthropogenic warming.”

Europe is also getting hotter. In 2003, 2015 and 2018 it was hit by severe summer heat waves and spells of drought that damaged plantations, crops and vines; the damage from drought was intensified by more virulent attacks from pathogens, insect outbreaks and tree death.

“Extreme conditions will become more frequent, which could be devastating for agriculture, ecosystems and societies as a whole”

In the baking summer of 2003, an estimated 70,000 people died because of extremes of heat. And, the researchers say, “a further increase in the frequency and severity of heat waves under projected global warming implies a multitude of harmful direct and indirect impacts on human health.”

In other words, things are bad now and are likely to get worse, according to a report by 17 British, European and Canadian researchers in the journal Nature Geoscience.

Dendrochronologists can and do routinely build up a picture of bygone temperatures by measuring the growth rings in trees: enough old living trees, and reliable knowledge about the felling of oaks for chateaux, cathedrals, sailing ships, fortresses and stockades can help pinpoint seasonal change on an annual basis.

But trees are also living chronicles of changes in carbon and oxygen isotope ratios − tiny atomic variations in the plant’s biochemistry − which provide evidence of rainfall and therefore a more precise picture of any growing season.

Wandering jet stream

The trees delivered mute evidence of very wet summers in 200, 720 and 1100 AD, and very dry summers in the years 40, 590, 950 and 1510 of the Common Era. But overall the big picture emerged: for the years 75 BC to 2018, Europe has slowly been getting drier.

Even so, the evidence from 2015 to 2018 shows that drought conditions in the area from which the trees were taken far exceeds anything in the previous centuries. The mostly likely explanation is the impact of ever-rising temperatures, driven by ever-higher greenhouse gas emissions from the ever-more profligate combustion of fossil fuels.

These temperatures are now considered high enough to affect the course of the stratospheric jet stream in ways that alter the long-term pattern of temperature and rainfall that defines a region’s climate.

“Climate change does not mean it will get drier everywhere,” said Ulf Büntgen, who holds research posts in the University of Cambridge, UK and the Czech Republic and Switzerland. “Some places may get wetter or colder, but extreme conditions will become more frequent, which could be devastating for agriculture, ecosystems and societies as a whole.” − Climate News Network

Global heating may be to blame for the fact that Europe has grown drier over the last 2,000 years to a new high in 2015.

LONDON, 17 March, 2021 − Europe has grown drier, an outcome shown by the continent’s last five summers, which have been marked by drought that has no parallel in the last two millennia.

Researchers studied two kinds of evidence delivered by 27,000 measurements taken from 21 living oak trees and 126 samples from ancient beams and rafters, to piece together a precise picture of the climate of Germany, Switzerland and the Czech Republic over the last 2,110 years.

They report, after 2015, that drought conditions intensified suddenly, in ways that were beyond anything over that entire 2000-year tract of time. And, they add, “this hydroclimatic anomaly is probably caused by anthropogenic warming.”

Europe is also getting hotter. In 2003, 2015 and 2018 it was hit by severe summer heat waves and spells of drought that damaged plantations, crops and vines; the damage from drought was intensified by more virulent attacks from pathogens, insect outbreaks and tree death.

“Extreme conditions will become more frequent, which could be devastating for agriculture, ecosystems and societies as a whole”

In the baking summer of 2003, an estimated 70,000 people died because of extremes of heat. And, the researchers say, “a further increase in the frequency and severity of heat waves under projected global warming implies a multitude of harmful direct and indirect impacts on human health.”

In other words, things are bad now and are likely to get worse, according to a report by 17 British, European and Canadian researchers in the journal Nature Geoscience.

Dendrochronologists can and do routinely build up a picture of bygone temperatures by measuring the growth rings in trees: enough old living trees, and reliable knowledge about the felling of oaks for chateaux, cathedrals, sailing ships, fortresses and stockades can help pinpoint seasonal change on an annual basis.

But trees are also living chronicles of changes in carbon and oxygen isotope ratios − tiny atomic variations in the plant’s biochemistry − which provide evidence of rainfall and therefore a more precise picture of any growing season.

Wandering jet stream

The trees delivered mute evidence of very wet summers in 200, 720 and 1100 AD, and very dry summers in the years 40, 590, 950 and 1510 of the Common Era. But overall the big picture emerged: for the years 75 BC to 2018, Europe has slowly been getting drier.

Even so, the evidence from 2015 to 2018 shows that drought conditions in the area from which the trees were taken far exceeds anything in the previous centuries. The mostly likely explanation is the impact of ever-rising temperatures, driven by ever-higher greenhouse gas emissions from the ever-more profligate combustion of fossil fuels.

These temperatures are now considered high enough to affect the course of the stratospheric jet stream in ways that alter the long-term pattern of temperature and rainfall that defines a region’s climate.

“Climate change does not mean it will get drier everywhere,” said Ulf Büntgen, who holds research posts in the University of Cambridge, UK and the Czech Republic and Switzerland. “Some places may get wetter or colder, but extreme conditions will become more frequent, which could be devastating for agriculture, ecosystems and societies as a whole.” − Climate News Network

UN survival plan offers new hope for the planet

A bold UN survival plan could put nature back in charge of the Earth − and researchers explain why that should happen.

LONDON, 26 February, 2021 − UN chiefs want to transform the world by putting nature back at the heart of global decision-making, arguing that the global economic shutdown triggered by the Covid-19 pandemic is an opportunity to change the planet for the better: for a stable climate, for cleaner air and water, and for a richer natural environment, thanks to the UN survival plan.

The goal? A more sustainable and more equitable world by 2030, a carbon-neutral world by 2050, a curb on global pollution and waste and a halt to ever-accelerating rates of wildlife extinction worldwide.

The methods? One of the first, in Making Peace With Nature, the new United Nations Environment Programme report, will be to incorporate what conservationists call “natural capital” into measures of national economic performance.

That is because forests, savannahs, wetlands and other natural habitats represent wealth, and their loss accelerates poverty. If nations and regions can reverse environmental decline then they can at the same time advance the alleviation of poverty, and secure reliable food and water, and good health, for all.

And to reinforce such arguments, new and entirely separate research continues to underline the UN vision of natural capital as real investment in the services on which all humankind depends.

Vital sanitation need

In 48 cities around the globe, nature provides at least 18% of the sanitation services: creatures in the soils filter and clean around 2.2 million cubic metres of human excrement in the form of pit latrines before it can reach the groundwater table.

Since, in 2017, around one fourth of the global population had no access to sanitation facilities, and 14% used toilets that disposed of waste on site, this is not just an important service but a vital one: vital to human health.

The same research team reports in the journal One Earth that − since more than 892 million people worldwide in effect release excrement into holes in the ground − then nature must sanitise more than 41 million tonnes of human waste every year before it gets into the groundwater. So that’s a service worth US$4.4 billion (£3.14bn) a year, British researchers calculate.

Around 70% of the world’s crops depend on insect pollination, and the range and abundance of insect pollinators is vulnerable to shifts in climate. Importantly, many crops rely on wild pollinators − that is, commercial honey bee colonies cannot always do the trick of turning flowers into fruit, or grain − so what happens to wild insect populations affects what is available for supper.

“The war on nature has left the planet broken. But it guides us by providing a peace plan and a post-war rebuilding programme”

US researchers report in the journal Ecological Applications that they took the case of wild bees and open field tomato crops: these depend on insects that release pollen by vibration, among them bumble bees.

They matched distribution of 15 species and climate data now against predictions for climate change across North America to find that − in the eastern US alone − within the next three to four decades, 11 species of pollinator could be in decline. The implications for food security are inescapable.

And a third study simply looked at what climate change, human population expansion, pollution and demand for freshwater had done to the planet’s rivers and lakes.

French and Chinese scientists report in the journal Science that they had identified what they call “marked changes” in the biodiversity of more than half the world’s rivers and lakes, thanks to human impact.

Of more than 1,000 fish species, 170 were extinct in their natural river basins, at a very conservative estimate. Out of 2,456 river basins, found everywhere except the deserts and the poles, 1,296 of them, covering more than 40% of the planet’s continental surface, and accounting for 37% of the length of the world’s rivers, revealed “deep and spatially distributed anthropogenic impacts.” That is science-speak for loss and defilement.

Lethal heat prospect

Such research − published on an almost daily basis − provides the context in which the latest UNEP report makes its argument. The report identifies a threefold planetary emergency and calls for advances in science and bold policy-making to make lives better both for the poorest in the world, and for nature itself.

It warns that the planet is heading for a warming of at least 3°C by the century’s end; that more than one million species could be heading for extinction; and that pollution-triggered diseases right now deliver an estimated nine million premature deaths each year.

“The war on nature has left the planet broken. But it also guides us to a safe place by providing a peace plan and a post-war rebuilding programme,” says António Guterres, UN secretary general, in the report’s foreword.

“By transforming how we view nature, we can recognise its true value. By reflecting this value in policies, plans and economic systems, we can channel investments into activities that restore nature and are rewarded for it.

“By recognising nature as an indispensable ally, we can unleash human ingenuity in the service of sustainability and secure our own health and well-being alongside that of the planet.” − Climate News Network

A bold UN survival plan could put nature back in charge of the Earth − and researchers explain why that should happen.

LONDON, 26 February, 2021 − UN chiefs want to transform the world by putting nature back at the heart of global decision-making, arguing that the global economic shutdown triggered by the Covid-19 pandemic is an opportunity to change the planet for the better: for a stable climate, for cleaner air and water, and for a richer natural environment, thanks to the UN survival plan.

The goal? A more sustainable and more equitable world by 2030, a carbon-neutral world by 2050, a curb on global pollution and waste and a halt to ever-accelerating rates of wildlife extinction worldwide.

The methods? One of the first, in Making Peace With Nature, the new United Nations Environment Programme report, will be to incorporate what conservationists call “natural capital” into measures of national economic performance.

That is because forests, savannahs, wetlands and other natural habitats represent wealth, and their loss accelerates poverty. If nations and regions can reverse environmental decline then they can at the same time advance the alleviation of poverty, and secure reliable food and water, and good health, for all.

And to reinforce such arguments, new and entirely separate research continues to underline the UN vision of natural capital as real investment in the services on which all humankind depends.

Vital sanitation need

In 48 cities around the globe, nature provides at least 18% of the sanitation services: creatures in the soils filter and clean around 2.2 million cubic metres of human excrement in the form of pit latrines before it can reach the groundwater table.

Since, in 2017, around one fourth of the global population had no access to sanitation facilities, and 14% used toilets that disposed of waste on site, this is not just an important service but a vital one: vital to human health.

The same research team reports in the journal One Earth that − since more than 892 million people worldwide in effect release excrement into holes in the ground − then nature must sanitise more than 41 million tonnes of human waste every year before it gets into the groundwater. So that’s a service worth US$4.4 billion (£3.14bn) a year, British researchers calculate.

Around 70% of the world’s crops depend on insect pollination, and the range and abundance of insect pollinators is vulnerable to shifts in climate. Importantly, many crops rely on wild pollinators − that is, commercial honey bee colonies cannot always do the trick of turning flowers into fruit, or grain − so what happens to wild insect populations affects what is available for supper.

“The war on nature has left the planet broken. But it guides us by providing a peace plan and a post-war rebuilding programme”

US researchers report in the journal Ecological Applications that they took the case of wild bees and open field tomato crops: these depend on insects that release pollen by vibration, among them bumble bees.

They matched distribution of 15 species and climate data now against predictions for climate change across North America to find that − in the eastern US alone − within the next three to four decades, 11 species of pollinator could be in decline. The implications for food security are inescapable.

And a third study simply looked at what climate change, human population expansion, pollution and demand for freshwater had done to the planet’s rivers and lakes.

French and Chinese scientists report in the journal Science that they had identified what they call “marked changes” in the biodiversity of more than half the world’s rivers and lakes, thanks to human impact.

Of more than 1,000 fish species, 170 were extinct in their natural river basins, at a very conservative estimate. Out of 2,456 river basins, found everywhere except the deserts and the poles, 1,296 of them, covering more than 40% of the planet’s continental surface, and accounting for 37% of the length of the world’s rivers, revealed “deep and spatially distributed anthropogenic impacts.” That is science-speak for loss and defilement.

Lethal heat prospect

Such research − published on an almost daily basis − provides the context in which the latest UNEP report makes its argument. The report identifies a threefold planetary emergency and calls for advances in science and bold policy-making to make lives better both for the poorest in the world, and for nature itself.

It warns that the planet is heading for a warming of at least 3°C by the century’s end; that more than one million species could be heading for extinction; and that pollution-triggered diseases right now deliver an estimated nine million premature deaths each year.

“The war on nature has left the planet broken. But it also guides us to a safe place by providing a peace plan and a post-war rebuilding programme,” says António Guterres, UN secretary general, in the report’s foreword.

“By transforming how we view nature, we can recognise its true value. By reflecting this value in policies, plans and economic systems, we can channel investments into activities that restore nature and are rewarded for it.

“By recognising nature as an indispensable ally, we can unleash human ingenuity in the service of sustainability and secure our own health and well-being alongside that of the planet.” − Climate News Network

Hope springs eternal for species facing extinction

Extinction is for ever, but not inevitable. Some threatened species are now surprising survivors. Can others follow suit?

LONDON, 22 February, 2021 − Scientists continue to issue strident warnings that the Earth faces a sixth mass extinction, and the evidence suggests they’re right.

There are some standout survivors, though − birds and mammals which not long ago appeared doomed but are now recovering. There is even a flickering hope that their resurgence could show the way to survival for some other species among the teeming millions at risk.

Researchers from the University of Newcastle, UK, and BirdLife International report in the journal Conservation Letters that different initiatives have prevented up to 32 bird and 16 mammal extinctions since 1993, the year the UN’s Convention on Biological Diversity entered into force.

As 10 bird and five mammal species are known to have become extinct in that time, the researchers think extinction rates would have been up to four times higher if humans had not acted to help the survivors.

“I think that’s a positive message. It’s not all bad news, always,” said Rike Bolam of the University of Newcastle, the study’s lead author. “It is encouraging that some of the species we studied have recovered very well.”

Success achieved

Stuart Butchart, chief scientist at BirdLife and an honorary research fellow in the zoology department of the University of Cambridge, said: “These results show that despite the overall failure to meet the targets for conserving nature set through the UN a decade ago, significant success in preventing extinctions was achieved.

“It would be easy to feel conservation was a pointless exercise and there’s nothing we can do to slow the juggernaut down. Broadly speaking, we have the tools, we just need much greater resource and political will.”

Many of the most successful conservation efforts involve what science knows as the charismatic megafauna, crowdpuller species such as the tiger, which may attract attention and funding relatively easily in their struggle to escape extinction. Most species do not.

But Bolam and Butchart’s team identified a number of recurring and widely applicable themes in trying to stem the catastrophic race towards oblivion: the removal of invasive species, for example, the management of hunting and protection of important habitats.

“We have the tools, we just need much greater resource and political will”

Saving the web of life intact to hand on to future generations the richness of species on which humanity depends won’t be easy. Adam Vaughan, chief reporter at the magazine New Scientist, writes: “Targeted actions won’t turn the tide alone. Stemming biodiversity loss will also require more fundamental changes to how we value nature – and whether those will be forthcoming is the trillion-dollar question.”

To give some idea of what works − and why − the magazine lists 10 survival success stories from around the world. It includes some obvious candidates, creatures which would be at the top of any keen zoologist’s bucket list − and probably most other people’s too. There’s the blue whale, obviously, its Antarctic sub-species reduced by hunters from an estimated 239,000 before industrial whaling started early in the last century to 360 by the early 1970s..

Yet by 2016 there were thought to be 4,500 in the southern ocean − something Jennifer Jackson at the British Antarctic Survey says has a wider lesson for conservation: “The blue whale recovery is symbolic of what humans can do if they just leave things alone.” Now, though, climate change is affecting the krill which are the whales’ main source of food. The possibility of extinction is returning.

China’s giant pandas declined fast in the 20th century. Political will and protected areas improved their prospects from “endangered” to “vulnerable.” The government has created 67 giant panda reserves since the 1960s, and in 1988 banned logging entirely in their habitats. “The determination and investment of the Chinese government is the key,” says Qiang Xu of WWF-China. But the pandas still need much more time before they’re safe.

Mountain gorilla numbers have risen from about 250 in 1981 to 1,063 today. Things were looking hopeful until last month, when a gorilla in a US zoo was found to have contracted Covid-19. Poaching and forest clearance for agriculture remain potent threats.

People matter

Indus river dolphins were once found along the entire 3,000 kms (1,860 miles) of the Indus, but their range fell to 1,300 kms (800 m). By 2001, their numbers had dropped to 1,200, largely because they become stranded and die in irrigation canals.

Acoustic devices help to deter the dolphins from entering the canals, but educating fishing communities and recruiting local people for ecotourism and monitoring has been the key to saving about 1,800 animals, says Uzma Khan of WWF-Pakistan. “I learned you cannot do anything without communities.”

Not every species on the New Scientist’s list will avoid extinction, let alone the countless others which will live and die unremarked. Not all of those listed is even a poster girl (or boy) for conservation.

The world’s most endangered primate, the Hainan gibbon, is endemic to the Chinese island of the same name, and probably not very widely-known. By 1980 its population had fallen from 2,000 to a total barely able to ensure survival − just nine animals. There are now thought to be around a slightly more secure 33 altogether. Wish them luck. − Climate New Network

Extinction is for ever, but not inevitable. Some threatened species are now surprising survivors. Can others follow suit?

LONDON, 22 February, 2021 − Scientists continue to issue strident warnings that the Earth faces a sixth mass extinction, and the evidence suggests they’re right.

There are some standout survivors, though − birds and mammals which not long ago appeared doomed but are now recovering. There is even a flickering hope that their resurgence could show the way to survival for some other species among the teeming millions at risk.

Researchers from the University of Newcastle, UK, and BirdLife International report in the journal Conservation Letters that different initiatives have prevented up to 32 bird and 16 mammal extinctions since 1993, the year the UN’s Convention on Biological Diversity entered into force.

As 10 bird and five mammal species are known to have become extinct in that time, the researchers think extinction rates would have been up to four times higher if humans had not acted to help the survivors.

“I think that’s a positive message. It’s not all bad news, always,” said Rike Bolam of the University of Newcastle, the study’s lead author. “It is encouraging that some of the species we studied have recovered very well.”

Success achieved

Stuart Butchart, chief scientist at BirdLife and an honorary research fellow in the zoology department of the University of Cambridge, said: “These results show that despite the overall failure to meet the targets for conserving nature set through the UN a decade ago, significant success in preventing extinctions was achieved.

“It would be easy to feel conservation was a pointless exercise and there’s nothing we can do to slow the juggernaut down. Broadly speaking, we have the tools, we just need much greater resource and political will.”

Many of the most successful conservation efforts involve what science knows as the charismatic megafauna, crowdpuller species such as the tiger, which may attract attention and funding relatively easily in their struggle to escape extinction. Most species do not.

But Bolam and Butchart’s team identified a number of recurring and widely applicable themes in trying to stem the catastrophic race towards oblivion: the removal of invasive species, for example, the management of hunting and protection of important habitats.

“We have the tools, we just need much greater resource and political will”

Saving the web of life intact to hand on to future generations the richness of species on which humanity depends won’t be easy. Adam Vaughan, chief reporter at the magazine New Scientist, writes: “Targeted actions won’t turn the tide alone. Stemming biodiversity loss will also require more fundamental changes to how we value nature – and whether those will be forthcoming is the trillion-dollar question.”

To give some idea of what works − and why − the magazine lists 10 survival success stories from around the world. It includes some obvious candidates, creatures which would be at the top of any keen zoologist’s bucket list − and probably most other people’s too. There’s the blue whale, obviously, its Antarctic sub-species reduced by hunters from an estimated 239,000 before industrial whaling started early in the last century to 360 by the early 1970s..

Yet by 2016 there were thought to be 4,500 in the southern ocean − something Jennifer Jackson at the British Antarctic Survey says has a wider lesson for conservation: “The blue whale recovery is symbolic of what humans can do if they just leave things alone.” Now, though, climate change is affecting the krill which are the whales’ main source of food. The possibility of extinction is returning.

China’s giant pandas declined fast in the 20th century. Political will and protected areas improved their prospects from “endangered” to “vulnerable.” The government has created 67 giant panda reserves since the 1960s, and in 1988 banned logging entirely in their habitats. “The determination and investment of the Chinese government is the key,” says Qiang Xu of WWF-China. But the pandas still need much more time before they’re safe.

Mountain gorilla numbers have risen from about 250 in 1981 to 1,063 today. Things were looking hopeful until last month, when a gorilla in a US zoo was found to have contracted Covid-19. Poaching and forest clearance for agriculture remain potent threats.

People matter

Indus river dolphins were once found along the entire 3,000 kms (1,860 miles) of the Indus, but their range fell to 1,300 kms (800 m). By 2001, their numbers had dropped to 1,200, largely because they become stranded and die in irrigation canals.

Acoustic devices help to deter the dolphins from entering the canals, but educating fishing communities and recruiting local people for ecotourism and monitoring has been the key to saving about 1,800 animals, says Uzma Khan of WWF-Pakistan. “I learned you cannot do anything without communities.”

Not every species on the New Scientist’s list will avoid extinction, let alone the countless others which will live and die unremarked. Not all of those listed is even a poster girl (or boy) for conservation.

The world’s most endangered primate, the Hainan gibbon, is endemic to the Chinese island of the same name, and probably not very widely-known. By 1980 its population had fallen from 2,000 to a total barely able to ensure survival − just nine animals. There are now thought to be around a slightly more secure 33 altogether. Wish them luck. − Climate New Network

Refugees and wildlife face risk from border walls

Not only humans but four-legged migrants are at risk from  border walls. Other species can be climate refugees too.

LONDON, 17 February 2021 − Something there is, wrote the American poet Robert Frost, “that does not love a wall.” Thanks to British researchers we now know that something is the white-lipped peccary, the jaguar and the southern spotted skunk. All of them − and many other species − could be affected by border walls like that separating  the US from Mexico.

The barrier between India and Myanmar, too, creates problems for the sloth bear, the Indian pangolin and the large spotted civet. And a fence along the Sino-Russian borders could be hard on the desert hare, the Tibetan antelope, the goitered gazelle and the Tibetan fox. When things become harsh on one side of the wall, none of them can move to a better home.

Which could be bad news because, as the planet heats up, and regional climate zones begin to shift, around one in three mammals and birds could by 2070 be forced to look for more welcoming habitat in another country.

Around 3,200 kilometres of man-made barrier now extend along national boundaries, precisely to prevent the unauthorised movement of refugees. But those same barriers could create problems for some of the 700 or so mammals that may have to shift home as regional climates change, according to a study in the Proceedings of the National Academy of Sciences.

The US-Mexican border wall alone could obstruct the migration of 122 species of four-legged animal refugee.

“If we are serious about protecting nature, reducing the impacts of border barriers on species will be really important − although there’s no substitute for tackling the greenhouse gas emissions at the root of the issue”

“Species all across the planet are on the move as they respond to a changing climate. Our findings show how important it is that species can move across national boundaries through connected habitats in order to cope with this change,” said Stephen Willis of Durham University in the UK.

“Borders that are fortified with walls and fences pose a serious threat to any species that can’t get across them. If we are serious about protecting nature, expanding transboundary conservation initiatives and reducing the impacts of border barriers on species will be really important − although there’s no substitute for tackling the greenhouse gas emissions at the root of the issue.”

Professor Willis and his colleagues started from the premise that the effectiveness of conservation action is not separable from what they call “underlying sociopolitical factors.”

There has, for more than a decade, been serious concern that climate change and human population expansion could ultimately lead to a mass extinction of wild creatures.

But mathematical models of the natural niches occupied by birds and mammals worldwide show that the biggest losses of native species will be in those countries with weaker governance and lower Gross Domestic Product.

No justice

And the disappearance of mammals in particular will be in those countries with the lowest levels of the greenhouse gas emissions that fuel climate change.

To survive, many of those species will have to migrate − and at that point, walls and fences designed to exclude human migrants will become major obstacles to the conservation of the wild things. The margay and the common opossum, the Mexican wolf and that wild cat the jaguarundi could all be turned back, along with hungry and near-desperate families, at the US-Mexican border.

“The stark inequities between those who contributed most to climate change and those who will be most impacted raise really important questions of international justice,” said Mark Titley, a researcher at Durham who led the study.

“Fortunately, our models also show how strong and urgent emissions reductions, in line with the Paris Agreement, could greatly reduce the impacts on biodiversity and relieve the burden of such losses on less wealthy nations.”

Or, as Robert Frost put it:

“Before I built a wall I’d ask to know What I was walling in or walling out…”

− Climate News Network

Not only humans but four-legged migrants are at risk from  border walls. Other species can be climate refugees too.

LONDON, 17 February 2021 − Something there is, wrote the American poet Robert Frost, “that does not love a wall.” Thanks to British researchers we now know that something is the white-lipped peccary, the jaguar and the southern spotted skunk. All of them − and many other species − could be affected by border walls like that separating  the US from Mexico.

The barrier between India and Myanmar, too, creates problems for the sloth bear, the Indian pangolin and the large spotted civet. And a fence along the Sino-Russian borders could be hard on the desert hare, the Tibetan antelope, the goitered gazelle and the Tibetan fox. When things become harsh on one side of the wall, none of them can move to a better home.

Which could be bad news because, as the planet heats up, and regional climate zones begin to shift, around one in three mammals and birds could by 2070 be forced to look for more welcoming habitat in another country.

Around 3,200 kilometres of man-made barrier now extend along national boundaries, precisely to prevent the unauthorised movement of refugees. But those same barriers could create problems for some of the 700 or so mammals that may have to shift home as regional climates change, according to a study in the Proceedings of the National Academy of Sciences.

The US-Mexican border wall alone could obstruct the migration of 122 species of four-legged animal refugee.

“If we are serious about protecting nature, reducing the impacts of border barriers on species will be really important − although there’s no substitute for tackling the greenhouse gas emissions at the root of the issue”

“Species all across the planet are on the move as they respond to a changing climate. Our findings show how important it is that species can move across national boundaries through connected habitats in order to cope with this change,” said Stephen Willis of Durham University in the UK.

“Borders that are fortified with walls and fences pose a serious threat to any species that can’t get across them. If we are serious about protecting nature, expanding transboundary conservation initiatives and reducing the impacts of border barriers on species will be really important − although there’s no substitute for tackling the greenhouse gas emissions at the root of the issue.”

Professor Willis and his colleagues started from the premise that the effectiveness of conservation action is not separable from what they call “underlying sociopolitical factors.”

There has, for more than a decade, been serious concern that climate change and human population expansion could ultimately lead to a mass extinction of wild creatures.

But mathematical models of the natural niches occupied by birds and mammals worldwide show that the biggest losses of native species will be in those countries with weaker governance and lower Gross Domestic Product.

No justice

And the disappearance of mammals in particular will be in those countries with the lowest levels of the greenhouse gas emissions that fuel climate change.

To survive, many of those species will have to migrate − and at that point, walls and fences designed to exclude human migrants will become major obstacles to the conservation of the wild things. The margay and the common opossum, the Mexican wolf and that wild cat the jaguarundi could all be turned back, along with hungry and near-desperate families, at the US-Mexican border.

“The stark inequities between those who contributed most to climate change and those who will be most impacted raise really important questions of international justice,” said Mark Titley, a researcher at Durham who led the study.

“Fortunately, our models also show how strong and urgent emissions reductions, in line with the Paris Agreement, could greatly reduce the impacts on biodiversity and relieve the burden of such losses on less wealthy nations.”

Or, as Robert Frost put it:

“Before I built a wall I’d ask to know What I was walling in or walling out…”

− Climate News Network

Wild flowers and bees contend with climate heat

Many alpine flowers could soon fade out. Some bees may be buzzing off. The wild things are victims of climate heat.

LONDON, 9 February, 2021 − Thanks to climate heat, this could be the last farewell to mossy saxifrage, to alpine wormwood and mignonette-leafed bittercress. With them could go plants most people could hardly name: dwarf cudweed, alpine stonecrop, mossy cyphel, cobweb houseleek and two kinds of hawkweed. All of them are mountain-dwellers, hardy little plants that depend for their existence on alpine glaciers.

And almost everywhere in the world, high-altitude rivers of ice are in retreat. Global heating, climate change and human disturbance alter both the conditions for growth and the rich variety of life.

In the same week that one team of researchers listed the alpine flowers threatened with extinction, another team of scientists assembled an inventory of observations of wild bees, to find that a quarter of the world’s 20,000 bee species have not been recorded in the last 25 years.

Bees and flowers are interdependent: they evolved together and would perish together. But climate change threatens to take a selective toll on a range of alpine plants − beloved of gardeners but also important in liqueurs and medicines − as glaciers retreat in the mountainous regions.

These little flowers are to be found variously in the Sierra Nevada in Spain, the Apennines in Italy, along the spine of the Alps in Switzerland and Austria, and even in the highlands of Scotland.

And one day, according to a new study in the journal Frontiers in Ecology and Evolution, many or all of them could be locally extinct.

“Something is happening to the bees, and something needs to be done … The next step is prodding policymakers into action while we still have time. The bees cannot wait”

The wildflowers listed in the first two sentences − Saxifraga bryoides, Artemisia genipi, Cardamine resedifolia, Leucanthemopsis alpina, Gnaphalium supinum, Sedum alpestre, Minuartia sedoides, Sempervivum arachnoideum, Hieracium staticifolium and H. glanduliferum − could all go, and another suite of alpine opportunists could take advantage of their living space.

Californian researchers report that they looked at 117 plant species and matched them with geological evidence from four glaciers in the Italian Alps, and then used computational systems to calculate how plant communities have changed over the last five thousand years, and what might happen as the glaciers continue to retreat.

They found that as the glaciers disappear, more than one in five of their sample alpines could also vanish. The loss of that 22% however could be to the benefit of around 29% of the surveyed species, among them the snow gentian, Gentiana nivalis and the dwarf yellow cinquefoil Potentialla aurea. Some alpines would probably not be affected: among them alpine lovage or Ligusticum mutellina and Pedicularis kerneri, a variety of lousewort.

The authors make no mention of one alpine almost everybody in the world could name: Leontopodium nivale or edelweiss. But what happens to even the most insignificant wild plants matters to everybody.

“Plants are the primary producers at the basis of the food web that sustained our lives and economies, and biodiversity is the key to healthy ecosystems − biodiversity also represents an inestimable cultural value that needs to be properly supported,” said Gianalberto Losapio, a biologist at Stanford University in the US.

Growing interest

Meanwhile in Argentina researchers decided to take advantage of citizen science to check on some of the flower world’s biggest fans, the wild bees. There has been huge concern about observed decline in insect abundance, as wild ecosystems are colonised by humans and global average temperatures rise to change the world’s weather systems.

But over the same decades, there has also been a dramatic increase in informed interest in the wild things, among gardeners, bird-watchers and butterfly lovers, and an exponential rise in records available to an international network of databases called the Global Biodiversity Information Facility.

And, say researchers in the journal One Earth, as global records soar, the number of bee species listed in those records has gone down. Around 25% fewer species were recorded between 2006 and 2015 than were listed in the 1990s.

Wild bees have a role in the pollination of about 85% of the world’s food crops. Without the bees, many wild flowers could not replicate.

“It’s not exactly a bee cataclysm yet, but what we can say is that wild bees are not exactly thriving,” said Eduardo Zattara, a biodiversity researcher at CONICET-Universidad Nacional del Comahue.

“Something is happening to the bees, and something needs to be done. We cannot wait until we have absolute certainty because we rarely get there in the natural sciences. The next step is prodding policymakers into action while we still have time. The bees cannot wait.” − Climate News Network

Many alpine flowers could soon fade out. Some bees may be buzzing off. The wild things are victims of climate heat.

LONDON, 9 February, 2021 − Thanks to climate heat, this could be the last farewell to mossy saxifrage, to alpine wormwood and mignonette-leafed bittercress. With them could go plants most people could hardly name: dwarf cudweed, alpine stonecrop, mossy cyphel, cobweb houseleek and two kinds of hawkweed. All of them are mountain-dwellers, hardy little plants that depend for their existence on alpine glaciers.

And almost everywhere in the world, high-altitude rivers of ice are in retreat. Global heating, climate change and human disturbance alter both the conditions for growth and the rich variety of life.

In the same week that one team of researchers listed the alpine flowers threatened with extinction, another team of scientists assembled an inventory of observations of wild bees, to find that a quarter of the world’s 20,000 bee species have not been recorded in the last 25 years.

Bees and flowers are interdependent: they evolved together and would perish together. But climate change threatens to take a selective toll on a range of alpine plants − beloved of gardeners but also important in liqueurs and medicines − as glaciers retreat in the mountainous regions.

These little flowers are to be found variously in the Sierra Nevada in Spain, the Apennines in Italy, along the spine of the Alps in Switzerland and Austria, and even in the highlands of Scotland.

And one day, according to a new study in the journal Frontiers in Ecology and Evolution, many or all of them could be locally extinct.

“Something is happening to the bees, and something needs to be done … The next step is prodding policymakers into action while we still have time. The bees cannot wait”

The wildflowers listed in the first two sentences − Saxifraga bryoides, Artemisia genipi, Cardamine resedifolia, Leucanthemopsis alpina, Gnaphalium supinum, Sedum alpestre, Minuartia sedoides, Sempervivum arachnoideum, Hieracium staticifolium and H. glanduliferum − could all go, and another suite of alpine opportunists could take advantage of their living space.

Californian researchers report that they looked at 117 plant species and matched them with geological evidence from four glaciers in the Italian Alps, and then used computational systems to calculate how plant communities have changed over the last five thousand years, and what might happen as the glaciers continue to retreat.

They found that as the glaciers disappear, more than one in five of their sample alpines could also vanish. The loss of that 22% however could be to the benefit of around 29% of the surveyed species, among them the snow gentian, Gentiana nivalis and the dwarf yellow cinquefoil Potentialla aurea. Some alpines would probably not be affected: among them alpine lovage or Ligusticum mutellina and Pedicularis kerneri, a variety of lousewort.

The authors make no mention of one alpine almost everybody in the world could name: Leontopodium nivale or edelweiss. But what happens to even the most insignificant wild plants matters to everybody.

“Plants are the primary producers at the basis of the food web that sustained our lives and economies, and biodiversity is the key to healthy ecosystems − biodiversity also represents an inestimable cultural value that needs to be properly supported,” said Gianalberto Losapio, a biologist at Stanford University in the US.

Growing interest

Meanwhile in Argentina researchers decided to take advantage of citizen science to check on some of the flower world’s biggest fans, the wild bees. There has been huge concern about observed decline in insect abundance, as wild ecosystems are colonised by humans and global average temperatures rise to change the world’s weather systems.

But over the same decades, there has also been a dramatic increase in informed interest in the wild things, among gardeners, bird-watchers and butterfly lovers, and an exponential rise in records available to an international network of databases called the Global Biodiversity Information Facility.

And, say researchers in the journal One Earth, as global records soar, the number of bee species listed in those records has gone down. Around 25% fewer species were recorded between 2006 and 2015 than were listed in the 1990s.

Wild bees have a role in the pollination of about 85% of the world’s food crops. Without the bees, many wild flowers could not replicate.

“It’s not exactly a bee cataclysm yet, but what we can say is that wild bees are not exactly thriving,” said Eduardo Zattara, a biodiversity researcher at CONICET-Universidad Nacional del Comahue.

“Something is happening to the bees, and something needs to be done. We cannot wait until we have absolute certainty because we rarely get there in the natural sciences. The next step is prodding policymakers into action while we still have time. The bees cannot wait.” − Climate News Network

Overheated Earth can slow plants’ carbon storage

For vast tracts of forest and savannah, the heat could rise too far for plants’ carbon storage abilities to go on working.

LONDON, 15 January, 2020 − Climate change could be about to slowly shut down the planet’s most vital life-support ability: the functioning of plants’ carbon storage system, which protects the Earth by absorbing the greenhouse gas before it can enter the atmosphere.

Green things driven by photosynthesis right now soak up around one-third of all the greenhouse gas emitted from vehicle exhausts and power station chimneys. But in the next two or three decades, their capacity to do this could be halved, because rapidly rising atmospheric temperatures will set a limit.

At that limiting point, the ability of forests, grasslands and even crops to capture and hold atmospheric carbon, the nourishment for all life on Earth, will start to diminish.

For one important group of plants − these include rice, soy, pulses, grasses, oaks, pines and so on − photosynthesis happens at a peak rate at 18°C. At higher temperatures, the process becomes less efficient and the plant begins to respire: that is, gulp oxygen and breathe out carbon dioxide.

For a second, smaller group − one that includes maize and sugar cane and just one group of trees − that temperature tipping point is 28°C. And researchers report in the journal Science Advances that, by 2050, temperatures will have risen in ways that will limit the efficiency of photosynthesis by around 45%.

“The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years”

The finding is based not just on computer simulation and theoretical models, but on direct observation. Researchers used directly measured data of sunlight, water and carbon dioxide action from 1991 to 2015 at a network of scientific instruments placed in every major ecosystem around the globe to identify these temperature tipping points.

And they warn that the mean or average temperature for the warmest three months of the year had already passed the thermal maximum for photosynthesis “some time in the last decade.”

Right now, only about a tenth of the forests and grasslands are exposed to temperatures beyond such thresholds, and then only for a short period. But greenhouse gas emissions continue to rise and global temperatures continue to soar. In time, half the planet could start to experience such temperatures.

The scientists warn that if humans go on clearing natural forests and burning fossil fuels at the present rates − climate scientists call this the “business-as-usual scenario” − then the capacity of the vegetable world to absorb atmospheric carbon could be almost halved as early as 2040.

Researchers have repeatedly warned that climate change in one way or another was likely to compromise the capacity of some natural ecosystems to go on doing what they have done for the last 10,000 years. But this study is one of the first to consider the green world as a whole.

Capacity halved

“The Earth has a steadily growing fever and, much like the human body, we know every biological process has a range of temperatures at which it performs optimally, and ones above which function deteriorates,” said Katharyn Duffy, of Northern Arizona University, who led the study. “So, we wanted to ask, how much can plants withstand?”

The US scientists and colleagues from New Zealand give their answer to the conundrum of plants’ carbon storage with a clarity and simplicity rare in scientific papers. “The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years,” they warn.

“Without mitigating warming, we will cross the temperature threshold of the most productive biomes by mid-century, after which the land sink will degrade.”

And if the plant world does not adapt, the capacity of the land to absorb surplus atmospheric carbon will drop to around 50% of its present range. And, the scientists warn, the process may not be a smooth, barely-perceptible decline: disturbance in a lot of landscapes could be rapid and precipitous.

They conclude: “Failure to implement agreements that meet or exceed limits in the Paris Accord could quantitatively alter the large and persistent terrestrial carbon sink, on which we currently depend to mitigate anthropogenic emissions of CO2 and therefore global environmental change.” − Climate News Network

For vast tracts of forest and savannah, the heat could rise too far for plants’ carbon storage abilities to go on working.

LONDON, 15 January, 2020 − Climate change could be about to slowly shut down the planet’s most vital life-support ability: the functioning of plants’ carbon storage system, which protects the Earth by absorbing the greenhouse gas before it can enter the atmosphere.

Green things driven by photosynthesis right now soak up around one-third of all the greenhouse gas emitted from vehicle exhausts and power station chimneys. But in the next two or three decades, their capacity to do this could be halved, because rapidly rising atmospheric temperatures will set a limit.

At that limiting point, the ability of forests, grasslands and even crops to capture and hold atmospheric carbon, the nourishment for all life on Earth, will start to diminish.

For one important group of plants − these include rice, soy, pulses, grasses, oaks, pines and so on − photosynthesis happens at a peak rate at 18°C. At higher temperatures, the process becomes less efficient and the plant begins to respire: that is, gulp oxygen and breathe out carbon dioxide.

For a second, smaller group − one that includes maize and sugar cane and just one group of trees − that temperature tipping point is 28°C. And researchers report in the journal Science Advances that, by 2050, temperatures will have risen in ways that will limit the efficiency of photosynthesis by around 45%.

“The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years”

The finding is based not just on computer simulation and theoretical models, but on direct observation. Researchers used directly measured data of sunlight, water and carbon dioxide action from 1991 to 2015 at a network of scientific instruments placed in every major ecosystem around the globe to identify these temperature tipping points.

And they warn that the mean or average temperature for the warmest three months of the year had already passed the thermal maximum for photosynthesis “some time in the last decade.”

Right now, only about a tenth of the forests and grasslands are exposed to temperatures beyond such thresholds, and then only for a short period. But greenhouse gas emissions continue to rise and global temperatures continue to soar. In time, half the planet could start to experience such temperatures.

The scientists warn that if humans go on clearing natural forests and burning fossil fuels at the present rates − climate scientists call this the “business-as-usual scenario” − then the capacity of the vegetable world to absorb atmospheric carbon could be almost halved as early as 2040.

Researchers have repeatedly warned that climate change in one way or another was likely to compromise the capacity of some natural ecosystems to go on doing what they have done for the last 10,000 years. But this study is one of the first to consider the green world as a whole.

Capacity halved

“The Earth has a steadily growing fever and, much like the human body, we know every biological process has a range of temperatures at which it performs optimally, and ones above which function deteriorates,” said Katharyn Duffy, of Northern Arizona University, who led the study. “So, we wanted to ask, how much can plants withstand?”

The US scientists and colleagues from New Zealand give their answer to the conundrum of plants’ carbon storage with a clarity and simplicity rare in scientific papers. “The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years,” they warn.

“Without mitigating warming, we will cross the temperature threshold of the most productive biomes by mid-century, after which the land sink will degrade.”

And if the plant world does not adapt, the capacity of the land to absorb surplus atmospheric carbon will drop to around 50% of its present range. And, the scientists warn, the process may not be a smooth, barely-perceptible decline: disturbance in a lot of landscapes could be rapid and precipitous.

They conclude: “Failure to implement agreements that meet or exceed limits in the Paris Accord could quantitatively alter the large and persistent terrestrial carbon sink, on which we currently depend to mitigate anthropogenic emissions of CO2 and therefore global environmental change.” − Climate News Network

More trees may do less to slow the climate crisis

In theory, more trees should mean a lower risk of dangerous climate change. In practice, it may not be so simple.

LONDON, 6 January, 2021 − The belief that more trees and better-protected forests can help contain climate change looks a little less sure − if only because climate change has already begun to affect the world’s trees and forests.

Researchers have in the last few weeks established a panoply of evidence that higher temperatures and more carbon dioxide may not be recipes for green growth in a greenhouse world.

In the tropics, as the thermometer rises, trees grow more vigorously − but overall lifespans are getting shorter. This must ultimately make the forests less efficient as absorbers of atmospheric carbon.

To compound the hazard to the rainforests, the proportion of the canopy that has always been fire-resistant is showing signs of decrease: in parts of Indonesia, only 10% of the forests remain fireproof.

Climate change and more importantly human disturbance continues to put the survival of whole groups of plants at risk: a new study finds that almost one-third of all the world’s 430 oak species are in danger of extinction.

A separate study of 447 North American trees suggests that they might not have what it takes to keep pace with changes in temperature and rainfall expected in a world of global heating.

Limited gains

And there is yet further evidence that more carbon dioxide does not inevitably mean more potential nourishment for plants: a study by the US space agency Nasa suggests that what scientists call the “carbon dioxide fertilisation effect” has been dwindling since 1982.

Finally, even the gains inevitable with rising temperatures in some regions could be limited. Another Nasa study finds that although Siberia, Canada and Alaska are becoming greener as the mercury rises, the increasing drought and tree death in the Amazon rainforest and others has offset this: another blow for those who hope more growth means more carbon absorption.

None of this should be a great surprise: the more researchers look in fine detail at the challenge of restoring natural habitat as part of the planetary arsenal against climate change, the more problems they have identified.

Although researchers have demonstrated that massive forest planting and restoration could in principle reduce the extra atmospheric carbon amassed over the last century, the details are less certain.

With more heat comes more drought which could turn some forests into sources of carbon rather than sinks. The increasing heat could affect the ability of some species to germinate, thus changing the makeup of the forests.

Trees may not only be dying younger, but growing shorter as conditions change.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C”

And although spring is occurring ever earlier, so is leaf fall: all these things reduce the efficiency of forests as greedy consumers of carbon.

So the latest harvest of research is simply further confirmation that the global heating to which the world is already committed is going to change the nature of those habitats that have − until now − kept the planet at an even temperature.

That means that restoring forests is not just a matter of planting trees: foresters will need to identify the right trees for climate regimes that have yet to be established.

Tropical rainforests cover only 7% of the planet’s land surface, but they shelter and nourish around half of all the planet’s plants and animal species. Around half of the Earth’s stocks of sequestered carbon are locked in the trunks, branches, leaves and roots.

Researchers report in the Proceedings of the National Academy of Sciences that they examined growth data from more than 100,000 trees of 438 different species found at 3,433 places around the world. They found that as temperatures go beyond 25°C, tree lifespans decline.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C,” said Emanuel Gloor, of the University of Leeds in the UK, one of the authors.

Human interference

“Our findings, which are the first to demonstrate that there is a temperature threshold, suggest that for trees in this region, their longevity is likely to be negatively affected.”

Rainforests maintain their own microclimates: they keep themselves humid, and therefore more or less fireproof, as long as they remain intact, even during a drought. Researchers report in Communications Earth & Environment that they found 90% of the natural forest cover of Sumatra and Kalimantan had been so badly degraded by human clearance and disturbance that it was no longer fire-resistant. What was true for Indonesia could probably be true too for Central Africa or the Amazon.

“Contrary to the widely-held perception that worsening droughts are threatening the remaining rainforests, tropical forests in Indonesia become susceptible to fire only after human disturbance,” said Tadas Nikonovas of Swansea University in Wales, who led the research.

Human disturbance of natural wilderness threatens not just forests as a whole, but individual species of trees, each of which can be a natural ecosystem, supporting other plants and animals. English oaks, for instance, provide food and shelter to more than 2,300 kinds of moss, fungus, lichen, bird, mammal and insect.

Researchers for the Morton Arboretum in Illinois in the US report that of the world’s 430 species of oak, 113 are threatened with extinction: these include 32 species in Mexico, 36 in China, 20 in Vietnam and 16 in the US.

Tropical trees have naturally faster life-cycles. Trees in cooler regions can on average survive for more than 300 years. Climate change however is likely to happen over a few decades. Can trees keep pace with change at that rate?

Plants need water

Researchers from the University of Maine report in the Journal of Biogeography that they think not. They looked at the climatic ranges most suitable for 447 North American trees and shrubs to find that overall, these were at only 48.6% of their full potential. That is, the trees are no longer in equilibrium with present climate, and must increasingly be at a disadvantage as climate change accelerates.

And although the main driver of global heating and thus climate change − ever-higher ratios of carbon dioxide in the atmosphere − confers some advantage on species that live by photosynthesis, this advantage may not be guaranteed. A space-based study in the journal Science found that over the last four decades, as CO2 ratios in the atmosphere rose, 86% of terrestrial ecosystems became progressively less efficient at absorbing the stuff.

That is, the world’s green canopies have slowed climate change, but their ability to go on doing so may be limited. That is because even though more carbon dioxide should mean more growth, unless there is more nitrogen and more soil moisture as well, a plant’s capacity to respond is limited.

And that, says a second study, in the journal AGU Advances, is less of a problem in some places than others. The Arctic is greening rapidly as average temperatures rise, and there is no shortage of moisture from the thawing permafrost, nor of partly decomposed plant material, to serve as nourishment.

A survey of growth from 1982 to 2016 found that carbon absorption increased in Canada, Alaska and Siberia. But global heating has begun to reduce soil moisture in the tropics, and the gains of the Arctic are not enough to offset losses in what had once been rainforest. Nor are the polar regions likely to go on getting ever-greener.

“I don’t expect that we have to wait another 35 years to see water limitations becoming a factor in the Arctic as well,” said one of the authors, Rolf Reichle, of the Goddard Space Flight Centre in Maryland in the US. − Climate News Network

In theory, more trees should mean a lower risk of dangerous climate change. In practice, it may not be so simple.

LONDON, 6 January, 2021 − The belief that more trees and better-protected forests can help contain climate change looks a little less sure − if only because climate change has already begun to affect the world’s trees and forests.

Researchers have in the last few weeks established a panoply of evidence that higher temperatures and more carbon dioxide may not be recipes for green growth in a greenhouse world.

In the tropics, as the thermometer rises, trees grow more vigorously − but overall lifespans are getting shorter. This must ultimately make the forests less efficient as absorbers of atmospheric carbon.

To compound the hazard to the rainforests, the proportion of the canopy that has always been fire-resistant is showing signs of decrease: in parts of Indonesia, only 10% of the forests remain fireproof.

Climate change and more importantly human disturbance continues to put the survival of whole groups of plants at risk: a new study finds that almost one-third of all the world’s 430 oak species are in danger of extinction.

A separate study of 447 North American trees suggests that they might not have what it takes to keep pace with changes in temperature and rainfall expected in a world of global heating.

Limited gains

And there is yet further evidence that more carbon dioxide does not inevitably mean more potential nourishment for plants: a study by the US space agency Nasa suggests that what scientists call the “carbon dioxide fertilisation effect” has been dwindling since 1982.

Finally, even the gains inevitable with rising temperatures in some regions could be limited. Another Nasa study finds that although Siberia, Canada and Alaska are becoming greener as the mercury rises, the increasing drought and tree death in the Amazon rainforest and others has offset this: another blow for those who hope more growth means more carbon absorption.

None of this should be a great surprise: the more researchers look in fine detail at the challenge of restoring natural habitat as part of the planetary arsenal against climate change, the more problems they have identified.

Although researchers have demonstrated that massive forest planting and restoration could in principle reduce the extra atmospheric carbon amassed over the last century, the details are less certain.

With more heat comes more drought which could turn some forests into sources of carbon rather than sinks. The increasing heat could affect the ability of some species to germinate, thus changing the makeup of the forests.

Trees may not only be dying younger, but growing shorter as conditions change.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C”

And although spring is occurring ever earlier, so is leaf fall: all these things reduce the efficiency of forests as greedy consumers of carbon.

So the latest harvest of research is simply further confirmation that the global heating to which the world is already committed is going to change the nature of those habitats that have − until now − kept the planet at an even temperature.

That means that restoring forests is not just a matter of planting trees: foresters will need to identify the right trees for climate regimes that have yet to be established.

Tropical rainforests cover only 7% of the planet’s land surface, but they shelter and nourish around half of all the planet’s plants and animal species. Around half of the Earth’s stocks of sequestered carbon are locked in the trunks, branches, leaves and roots.

Researchers report in the Proceedings of the National Academy of Sciences that they examined growth data from more than 100,000 trees of 438 different species found at 3,433 places around the world. They found that as temperatures go beyond 25°C, tree lifespans decline.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C,” said Emanuel Gloor, of the University of Leeds in the UK, one of the authors.

Human interference

“Our findings, which are the first to demonstrate that there is a temperature threshold, suggest that for trees in this region, their longevity is likely to be negatively affected.”

Rainforests maintain their own microclimates: they keep themselves humid, and therefore more or less fireproof, as long as they remain intact, even during a drought. Researchers report in Communications Earth & Environment that they found 90% of the natural forest cover of Sumatra and Kalimantan had been so badly degraded by human clearance and disturbance that it was no longer fire-resistant. What was true for Indonesia could probably be true too for Central Africa or the Amazon.

“Contrary to the widely-held perception that worsening droughts are threatening the remaining rainforests, tropical forests in Indonesia become susceptible to fire only after human disturbance,” said Tadas Nikonovas of Swansea University in Wales, who led the research.

Human disturbance of natural wilderness threatens not just forests as a whole, but individual species of trees, each of which can be a natural ecosystem, supporting other plants and animals. English oaks, for instance, provide food and shelter to more than 2,300 kinds of moss, fungus, lichen, bird, mammal and insect.

Researchers for the Morton Arboretum in Illinois in the US report that of the world’s 430 species of oak, 113 are threatened with extinction: these include 32 species in Mexico, 36 in China, 20 in Vietnam and 16 in the US.

Tropical trees have naturally faster life-cycles. Trees in cooler regions can on average survive for more than 300 years. Climate change however is likely to happen over a few decades. Can trees keep pace with change at that rate?

Plants need water

Researchers from the University of Maine report in the Journal of Biogeography that they think not. They looked at the climatic ranges most suitable for 447 North American trees and shrubs to find that overall, these were at only 48.6% of their full potential. That is, the trees are no longer in equilibrium with present climate, and must increasingly be at a disadvantage as climate change accelerates.

And although the main driver of global heating and thus climate change − ever-higher ratios of carbon dioxide in the atmosphere − confers some advantage on species that live by photosynthesis, this advantage may not be guaranteed. A space-based study in the journal Science found that over the last four decades, as CO2 ratios in the atmosphere rose, 86% of terrestrial ecosystems became progressively less efficient at absorbing the stuff.

That is, the world’s green canopies have slowed climate change, but their ability to go on doing so may be limited. That is because even though more carbon dioxide should mean more growth, unless there is more nitrogen and more soil moisture as well, a plant’s capacity to respond is limited.

And that, says a second study, in the journal AGU Advances, is less of a problem in some places than others. The Arctic is greening rapidly as average temperatures rise, and there is no shortage of moisture from the thawing permafrost, nor of partly decomposed plant material, to serve as nourishment.

A survey of growth from 1982 to 2016 found that carbon absorption increased in Canada, Alaska and Siberia. But global heating has begun to reduce soil moisture in the tropics, and the gains of the Arctic are not enough to offset losses in what had once been rainforest. Nor are the polar regions likely to go on getting ever-greener.

“I don’t expect that we have to wait another 35 years to see water limitations becoming a factor in the Arctic as well,” said one of the authors, Rolf Reichle, of the Goddard Space Flight Centre in Maryland in the US. − Climate News Network

Nature, not humans, may cause mass extinctions

Life on Earth has been through mass extinctions before − every 27 million years. Blame it on celestial clockwork.

LONDON, 18 December, 2020 − US scientists believe they have identified a recurring pattern of mass extinctions and catastrophic climate change − and this time humans really are not to blame.

Instead, the planet and the solar system could be caught up in some deadly astronomical cycle.

They argue that every 27 million years, a high proportion of land-dwelling species − birds, mammals, reptiles and amphibians − disappear from the fossil record at around the same time.

And this disappearance seems to coincide, again according to geological evidence, with devastating eruptions of volcanic lava and violent asteroid collisions that would have had the effect of darkening the skies, lowering the temperature, depleting the ozone layer, then stimulating a greenhouse effect and starting extensive fire and acid rain.

“It seems that large-body impacts and the pulses of internal Earth activity that create flood basalt volcanism may be marching to the same 27-million-year drumbeat as the extinctions, perhaps paced by our orbit in the galaxy,” said Michael Rampino, a biologist at New York University.

Serial crises

He and colleagues used statistical analysis to identify, in the journal Historical Biology, an ominous rhythm of catastrophe in the Earth’s deep history.

Such research highlights the extraordinary nature of the present life-on-Earth survival crisis. Earth is now undergoing what naturalists and geologists see as the Sixth Great Extinction in its 500-million-year fossil history, and potentially calamitous climate change, not because of any shift in planetary orbit or galactic traffic accident, but because of the human population explosion and the 200-year-long addiction to fossil fuels.

But researchers know the present crisis to be the latest of a series of crises in the long history of life on Earth only because of the capricious evidence of the fossil record, and they have spent the last half century trying to decipher some reason how and why these might have happened.

More than 40 years ago geologists began to see what they argued seemed to be cycles of destruction, followed by the slow restoration of the biodiversity of Earth.

“The global mass extinctions were apparently caused by the largest cataclysmic impacts and massive volcanism, perhaps sometimes working in concert”

Around that time, earth scientists found evidence of an asteroid impact that appeared to have wiped out the entire dinosaur lineage, along with seven-tenths of all species on land and sea. And some began to argue that mass extinctions might not be random events, but happen according to some kind of heavenly timetable.

Most of the evidence for such happenings comes from marine sediments: evidence of extinction in the oceans every 26 million years or so. Now Professor Rampino and his colleagues have looked at the record of mass extinctions on land, and found that these seem to follow a similar cycle spaced 27.5 million years apart.

In which case, there might be an agency to take the blame: the Milky Way Galaxy, of which the solar system and planet Earth is a very small part, moving at colossal speed.

Not only does the Earth orbit the Sun at 30 kms a second, the Sun and its planets waltz around the Galaxy at 220 kms a second, and make a complete revolution, astronomers think, about every 26 million to 30 million years. That means that any galactic traffic accident guarantees a collision at very high speed.

Suspect eruptions

And it could also mean that on every round trip, the Solar System passes through some kind of unidentified hazard zone that triggers showers of comet collisions and asteroid impacts.

“In fact three of the mass annihilations of species on land and in the sea are already known to have occurred at the same times as the three largest impacts of the last 250 million years, each capable of causing disaster and resulting mass extinctions,” Professor Rampino said.

But there is another more down-to-earth factor. All eight of those episodes of mass death on land and parallel extinction in the seas also matched periods of eruptions in which hot basalts flooded across the landscape.

All volcanic eruptions release carbon dioxide: in such cases enough to create conditions of intense cold followed by greenhouse warming,  acidification of the oceans and acid rain on land, destruction of the ozone layer that normally screens the planet from dangerous ultra-violet radiation, and even marine oxygen depletion. In which case life on the planet would have to withstand a kind of double assault.

“The global mass extinctions were apparently caused by the largest cataclysmic impacts and massive volcanism, perhaps sometimes working in concert,” Professor Rampino said. − Climate News Network

Life on Earth has been through mass extinctions before − every 27 million years. Blame it on celestial clockwork.

LONDON, 18 December, 2020 − US scientists believe they have identified a recurring pattern of mass extinctions and catastrophic climate change − and this time humans really are not to blame.

Instead, the planet and the solar system could be caught up in some deadly astronomical cycle.

They argue that every 27 million years, a high proportion of land-dwelling species − birds, mammals, reptiles and amphibians − disappear from the fossil record at around the same time.

And this disappearance seems to coincide, again according to geological evidence, with devastating eruptions of volcanic lava and violent asteroid collisions that would have had the effect of darkening the skies, lowering the temperature, depleting the ozone layer, then stimulating a greenhouse effect and starting extensive fire and acid rain.

“It seems that large-body impacts and the pulses of internal Earth activity that create flood basalt volcanism may be marching to the same 27-million-year drumbeat as the extinctions, perhaps paced by our orbit in the galaxy,” said Michael Rampino, a biologist at New York University.

Serial crises

He and colleagues used statistical analysis to identify, in the journal Historical Biology, an ominous rhythm of catastrophe in the Earth’s deep history.

Such research highlights the extraordinary nature of the present life-on-Earth survival crisis. Earth is now undergoing what naturalists and geologists see as the Sixth Great Extinction in its 500-million-year fossil history, and potentially calamitous climate change, not because of any shift in planetary orbit or galactic traffic accident, but because of the human population explosion and the 200-year-long addiction to fossil fuels.

But researchers know the present crisis to be the latest of a series of crises in the long history of life on Earth only because of the capricious evidence of the fossil record, and they have spent the last half century trying to decipher some reason how and why these might have happened.

More than 40 years ago geologists began to see what they argued seemed to be cycles of destruction, followed by the slow restoration of the biodiversity of Earth.

“The global mass extinctions were apparently caused by the largest cataclysmic impacts and massive volcanism, perhaps sometimes working in concert”

Around that time, earth scientists found evidence of an asteroid impact that appeared to have wiped out the entire dinosaur lineage, along with seven-tenths of all species on land and sea. And some began to argue that mass extinctions might not be random events, but happen according to some kind of heavenly timetable.

Most of the evidence for such happenings comes from marine sediments: evidence of extinction in the oceans every 26 million years or so. Now Professor Rampino and his colleagues have looked at the record of mass extinctions on land, and found that these seem to follow a similar cycle spaced 27.5 million years apart.

In which case, there might be an agency to take the blame: the Milky Way Galaxy, of which the solar system and planet Earth is a very small part, moving at colossal speed.

Not only does the Earth orbit the Sun at 30 kms a second, the Sun and its planets waltz around the Galaxy at 220 kms a second, and make a complete revolution, astronomers think, about every 26 million to 30 million years. That means that any galactic traffic accident guarantees a collision at very high speed.

Suspect eruptions

And it could also mean that on every round trip, the Solar System passes through some kind of unidentified hazard zone that triggers showers of comet collisions and asteroid impacts.

“In fact three of the mass annihilations of species on land and in the sea are already known to have occurred at the same times as the three largest impacts of the last 250 million years, each capable of causing disaster and resulting mass extinctions,” Professor Rampino said.

But there is another more down-to-earth factor. All eight of those episodes of mass death on land and parallel extinction in the seas also matched periods of eruptions in which hot basalts flooded across the landscape.

All volcanic eruptions release carbon dioxide: in such cases enough to create conditions of intense cold followed by greenhouse warming,  acidification of the oceans and acid rain on land, destruction of the ozone layer that normally screens the planet from dangerous ultra-violet radiation, and even marine oxygen depletion. In which case life on the planet would have to withstand a kind of double assault.

“The global mass extinctions were apparently caused by the largest cataclysmic impacts and massive volcanism, perhaps sometimes working in concert,” Professor Rampino said. − Climate News Network