Tag Archives: Agriculture

Rich world’s demands fell poorer world’s forests

The tropical forests maintain global climate and nurture the riches of nature. The rich world’s demands are destroying them.

LONDON, 9 April, 2021 − The world’s great ecosystems − moderators of climate, nurseries for evolution − are still being destroyed in the service of global trade, to meet the rich world’s demands. Once again, researchers have confirmed that the wealthy nations are in effect ploughing savanna and felling tropical forests at a distance.

In the first 15 years of this century, the growing demand from the well-heeled for chocolate, rubber, cotton, soy, beef and exotic timber has meant that poorer nations have actually increased their levels of deforestation.

In effect, every human in the G7 nations − Canada, France, Germany, Italy, Japan, the UK and the US − is responsible for the loss of at least four trees a year, mostly in the developing world.

And in a separate study in another journal, another team of scientists has examined satellite data to confirm that between 1985 and 2018, humans cleared or altered 268 million hectares of natural ecosystem on the continent of South America. This is 2.68 million sq kilometres: an area almost the size of Argentina.

Two scientists in Japan report in Nature Ecology and Evolution that they matched levels of deforestation against trade with the world’s biggest economies, to find a clear correlation. They could even distinguish demand in one rich country and its impact on the forests of a poorer nation.

“Richer countries are encouraging deforestation through demand for commodities”

“While cocoa consumption in Germany poses the highest risk to the forests in Côte d’Ivoire and Ghana, deforestation in coastal Tanzania is dominated by Japanese consumers for some agricultural commodities, such as cotton and sesame seed,” they write.

“China shares the most significant responsibility for deforestation in Indochina − particularly in northern Laos for timber and rubber.”

Ironically, many of the richer nations have expanded the areas of forest on their own soil. More than 90% of the deforestation caused by five of the G7 nations was beyond their own borders. In effect, the rich were exporting the destruction of the natural world, and the cost to the planet was disproportionate. The loss of three trees in the Amazon might be more damaging than the loss of 14 trees in Norway, the scientists argue.

“Most forests are in poorer countries who are overwhelmed with economic incentives to cut them down. Our findings show that richer countries are encouraging deforestation through demand for commodities,” said Keiichiro Kanemoto of the Research Institute for Humanity and Nature in Kyoto.

“Policies that aim to preserve forests need to also alleviate poverty. With the coronavirus pandemic, unemployment poses more challenges to forest conservation in developing countries. We want our data to assist in the policy making.”

South American losses

And in the journal Science Advances, a team from the University of Maryland reports on a closer look at the impact of demand for pulpwood, sugar cane, beef, corn and other commodities on one continent: South America, home to some of the world’s most important ecosystems.

They found that human impact on the continent’s land surface just between the years 1985 and 2018 had expanded by 60%. In those years the natural tree cover had dwindled by 16%, and the scale of pasture increased by 23%, cropland by 160% and plantation by 288%.

The sum of all the altered land reached 268 million hectares, or 2.68m sq kms. Argentina, which coincidentally covers 2.73m sq kms, saw an increase of only 23% in human conversion of land use. Brazil tipped the scales with an expansion of 65% in those years.

And, say the researchers, of all this altered land cover on the continent, around 55 million hectares had been degraded − that is, it was no longer functioning as an ecosystem − while being employed for no commercial return. This is the equivalent of more than half a million square kilometres: an area slightly bigger than France.

“No region on Earth is likely to have experienced the scale of land conversion for the sake of agricultural commodity production that South America has,” the authors write. − Climate News Network

The tropical forests maintain global climate and nurture the riches of nature. The rich world’s demands are destroying them.

LONDON, 9 April, 2021 − The world’s great ecosystems − moderators of climate, nurseries for evolution − are still being destroyed in the service of global trade, to meet the rich world’s demands. Once again, researchers have confirmed that the wealthy nations are in effect ploughing savanna and felling tropical forests at a distance.

In the first 15 years of this century, the growing demand from the well-heeled for chocolate, rubber, cotton, soy, beef and exotic timber has meant that poorer nations have actually increased their levels of deforestation.

In effect, every human in the G7 nations − Canada, France, Germany, Italy, Japan, the UK and the US − is responsible for the loss of at least four trees a year, mostly in the developing world.

And in a separate study in another journal, another team of scientists has examined satellite data to confirm that between 1985 and 2018, humans cleared or altered 268 million hectares of natural ecosystem on the continent of South America. This is 2.68 million sq kilometres: an area almost the size of Argentina.

Two scientists in Japan report in Nature Ecology and Evolution that they matched levels of deforestation against trade with the world’s biggest economies, to find a clear correlation. They could even distinguish demand in one rich country and its impact on the forests of a poorer nation.

“Richer countries are encouraging deforestation through demand for commodities”

“While cocoa consumption in Germany poses the highest risk to the forests in Côte d’Ivoire and Ghana, deforestation in coastal Tanzania is dominated by Japanese consumers for some agricultural commodities, such as cotton and sesame seed,” they write.

“China shares the most significant responsibility for deforestation in Indochina − particularly in northern Laos for timber and rubber.”

Ironically, many of the richer nations have expanded the areas of forest on their own soil. More than 90% of the deforestation caused by five of the G7 nations was beyond their own borders. In effect, the rich were exporting the destruction of the natural world, and the cost to the planet was disproportionate. The loss of three trees in the Amazon might be more damaging than the loss of 14 trees in Norway, the scientists argue.

“Most forests are in poorer countries who are overwhelmed with economic incentives to cut them down. Our findings show that richer countries are encouraging deforestation through demand for commodities,” said Keiichiro Kanemoto of the Research Institute for Humanity and Nature in Kyoto.

“Policies that aim to preserve forests need to also alleviate poverty. With the coronavirus pandemic, unemployment poses more challenges to forest conservation in developing countries. We want our data to assist in the policy making.”

South American losses

And in the journal Science Advances, a team from the University of Maryland reports on a closer look at the impact of demand for pulpwood, sugar cane, beef, corn and other commodities on one continent: South America, home to some of the world’s most important ecosystems.

They found that human impact on the continent’s land surface just between the years 1985 and 2018 had expanded by 60%. In those years the natural tree cover had dwindled by 16%, and the scale of pasture increased by 23%, cropland by 160% and plantation by 288%.

The sum of all the altered land reached 268 million hectares, or 2.68m sq kms. Argentina, which coincidentally covers 2.73m sq kms, saw an increase of only 23% in human conversion of land use. Brazil tipped the scales with an expansion of 65% in those years.

And, say the researchers, of all this altered land cover on the continent, around 55 million hectares had been degraded − that is, it was no longer functioning as an ecosystem − while being employed for no commercial return. This is the equivalent of more than half a million square kilometres: an area slightly bigger than France.

“No region on Earth is likely to have experienced the scale of land conversion for the sake of agricultural commodity production that South America has,” the authors write. − Climate News Network

Plants will be hit as a warming world turns drier

If a warming world becomes a drier one, how will the green things respond? Not well, according to a new prediction.

LONDON, 26 March, 2021 − The air of planet Earth has been gradually drying this century. If this goes on, that could be bad news for humankind. In a warming world crop harvests will dwindle, even in well-watered farmlands, and trees could shrink in height.

The prospect of stunted forests and shortages of food in a world hit by global heating, climate change and rapid population growth is ominous. But if US and Canadian scientists are right, it may be a simple consequence of plant response to a rarely-discussed worldwide phenomenon known as vapour pressure deficit, which has been rising for the past 20 years as the world has warmed.

The argument isn’t a simple one. Higher global temperatures mean more evaporation. Higher atmospheric temperatures also mean that the capacity of the atmosphere to hold moisture also rises − the rule of thumb is 7% more vapour per degree Celsius rise. So a warmer world should be a wetter world.

But climate science also predicts that although those regions already rainy will get rainier, the drylands and arid zones will get even dryer as the thermometer soars.

“As we race to increase production to feed a bigger population, this is a new hurdle. Atmospheric drying could limit yields, even in regions where irrigation or soil moisture is not limiting”

Now there is another factor in the calculations: vapour pressure deficit, or the overall drying of the atmosphere, and how plants react to the problem of dwindling atmospheric moisture.

New research in the journal Global Change Biology analyses 50 years of research and 112 plant species, and 59 physiological traits in those plants. The evidence suggests that atmospheric drying reduces plant yield, as the plants adjust to new conditions.

“When there is a high vapour pressure deficit, our atmosphere pulls water from other sources: animals, plants, etc. An increase in vapour pressure deficit places greater demand on the crop to use more water. In turn, this puts more pressure on farmers to ensure this demand for water is met − either via precipitation or irrigation − so that yields do not decrease,” said Walid Sadok, of the University of Minnesota.

“We believe a climate change-driven increase in atmospheric drying will reduce plant productivity and crop yields both in Minnesota and globally.”

The paradox is that plants can adjust to a changing world but in this case by becoming more drought-resistant. Which, in the case of wheat, maize and even birch trees, means growing less.

Less productive plants

Findings such as this are tentative, and will in any case be tested by time. But they also illustrate just how much there is yet to learn about the consequence of climate change in a complex, responsive world.

Other research teams have repeatedly observed that even in the drier regions, plants have so far responded to rising greenhouse gas emissions by an increase in global greenness. But there is nothing simple about the greenhouse effect. And there has been repeated evidence too that forest conservation and more tree plantations may not provide all the answers to the challenge of growth in an ever-warmer world.

The reasoning within the new study is that plant stomata, those tiny holes in foliage through which plants breathe and release water, adjust according to new conditions. The plants become more conservative. They grow shorter, smaller and more resistant to drought, even if there is no drought. And in parallel, they become less able to fix atmospheric carbon dioxide to provide new tissue. So, overall, plant productivity is reduced.

“As we race to increase production to feed a bigger population, this is a new hurdle that will need to be cleared,” said Dr Sadok. “Atmospheric drying could limit yields, even in regions where irrigation or soil moisture is not limiting, such as Minnesota.” − Climate News Network

If a warming world becomes a drier one, how will the green things respond? Not well, according to a new prediction.

LONDON, 26 March, 2021 − The air of planet Earth has been gradually drying this century. If this goes on, that could be bad news for humankind. In a warming world crop harvests will dwindle, even in well-watered farmlands, and trees could shrink in height.

The prospect of stunted forests and shortages of food in a world hit by global heating, climate change and rapid population growth is ominous. But if US and Canadian scientists are right, it may be a simple consequence of plant response to a rarely-discussed worldwide phenomenon known as vapour pressure deficit, which has been rising for the past 20 years as the world has warmed.

The argument isn’t a simple one. Higher global temperatures mean more evaporation. Higher atmospheric temperatures also mean that the capacity of the atmosphere to hold moisture also rises − the rule of thumb is 7% more vapour per degree Celsius rise. So a warmer world should be a wetter world.

But climate science also predicts that although those regions already rainy will get rainier, the drylands and arid zones will get even dryer as the thermometer soars.

“As we race to increase production to feed a bigger population, this is a new hurdle. Atmospheric drying could limit yields, even in regions where irrigation or soil moisture is not limiting”

Now there is another factor in the calculations: vapour pressure deficit, or the overall drying of the atmosphere, and how plants react to the problem of dwindling atmospheric moisture.

New research in the journal Global Change Biology analyses 50 years of research and 112 plant species, and 59 physiological traits in those plants. The evidence suggests that atmospheric drying reduces plant yield, as the plants adjust to new conditions.

“When there is a high vapour pressure deficit, our atmosphere pulls water from other sources: animals, plants, etc. An increase in vapour pressure deficit places greater demand on the crop to use more water. In turn, this puts more pressure on farmers to ensure this demand for water is met − either via precipitation or irrigation − so that yields do not decrease,” said Walid Sadok, of the University of Minnesota.

“We believe a climate change-driven increase in atmospheric drying will reduce plant productivity and crop yields both in Minnesota and globally.”

The paradox is that plants can adjust to a changing world but in this case by becoming more drought-resistant. Which, in the case of wheat, maize and even birch trees, means growing less.

Less productive plants

Findings such as this are tentative, and will in any case be tested by time. But they also illustrate just how much there is yet to learn about the consequence of climate change in a complex, responsive world.

Other research teams have repeatedly observed that even in the drier regions, plants have so far responded to rising greenhouse gas emissions by an increase in global greenness. But there is nothing simple about the greenhouse effect. And there has been repeated evidence too that forest conservation and more tree plantations may not provide all the answers to the challenge of growth in an ever-warmer world.

The reasoning within the new study is that plant stomata, those tiny holes in foliage through which plants breathe and release water, adjust according to new conditions. The plants become more conservative. They grow shorter, smaller and more resistant to drought, even if there is no drought. And in parallel, they become less able to fix atmospheric carbon dioxide to provide new tissue. So, overall, plant productivity is reduced.

“As we race to increase production to feed a bigger population, this is a new hurdle that will need to be cleared,” said Dr Sadok. “Atmospheric drying could limit yields, even in regions where irrigation or soil moisture is not limiting, such as Minnesota.” − Climate News Network

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

Longer summers will probably prove bummers

By the century’s end, longer summers could last for almost half the year − probably a bit too much for many of us.

LONDON, 18 March, 2021 − Summer’s lease, mourned William Shakespeare more than 400 years ago in one of his most quoted sonnets, “has all too short a date.” Not for much longer. Thanks to global heating, by the close of the century the longer summers arriving by then may have been extended to almost six months.

The lengthening of the northern hemisphere summer has already begun, according to a new study in the journal Geophysical Research Letters. The four seasons are normally defined as calendar events, pinned to the progress of a tilted planet in its annual orbit of the sun.

But Chinese scientists took a simpler approach. They defined summer’s commencement as the onset of temperatures in the hottest 25% of the year, winter by the coming of the coldest 25%.

And then they looked at the temperature data to work out what had already happened, and what is likely to happen as global average temperatures rise, in response to ever-higher greenhouse gas emissions linked to fossil fuel combustion and forest destruction.

They found that in 1952, summer could be counted as 78 days long; by 2011, this had stretched to 95 days in the northern hemisphere. Winter contracted from 76 to 73 days in duration. Spring had dwindled from 124 days to 115; autumn from 87 to 82 days.

Health risk

And if this trend continues, and humans go on burning fossil fuels under the notorious “business as usual” scenario, then by 2100 spring and autumn will go on diminishing, and winter will be over in just two months. Summer will however have been extended to nearly half the year.

“The changing seasonal clock,” the scientists write, “signifies disturbed agriculture seasons and rhythm of species activities, more frequent heat waves, storms and wildfires, amounting to increased risks to humanity.”

The findings will present no immediate surprise to farmers, nor to phenologists, those scientists who have spent a lifetime observing changes in the timing of the natural order: the first buds, the first leaves and flowers, the arrival of insects and migrating birds, all of them affected by the increasingly early arrival of spring.

The abbreviation of winter may not however make the natural world more fecund or productive: many crops and a very large number of deciduous trees rely for health and strength on a reliable period of winter chill, and a shorter winter is inevitably going to be a warmer one.

Conversely a long hot summer is unlikely to be particularly welcome: these will arrive with more intense, more enduring and more extensive heat waves, to pose a threat to both harvests and to human health for perhaps a billion or more people.

“The changing seasonal clock signifies disturbed agriculture seasons,  more frequent heat waves, storms and wildfires, amounting to increased risks to humanity”

The researchers warn that longer, hotter summers will affect the capacity to produce energy while at the same time accelerating demand for electricity to power air-conditioning systems.

Longer summers mean more stress for plants and for forests, more and larger wildfires and health hazards for outdoor workers.

Higher temperatures have been linked to high crime rates in some parts of the US and − the researchers warn − earlier and colder spring seasons can mean more “false springs” followed by severe frosts of the kind that, in 2012 in Michigan, cost fruit growers more than $500,000 in crop
losses.

In yet a further caution they say that virus-bearing mosquitos will have a wider range and longer breeding seasons, to produce sudden outbreaks of disease in regions once considered safe. Those sensitive to plant pollen will find the season of sneezes has suddenly got a lot longer.

“As global warming intensifies, the four seasons of a year no longer have equal months, and their onsets are irregular,” the authors write. This change of seasonal lengths, they add. can trigger a chain of reactions, and “policy-making for agricultural management, health care, and disaster prevention requires adjustment.” − Climate News Network

By the century’s end, longer summers could last for almost half the year − probably a bit too much for many of us.

LONDON, 18 March, 2021 − Summer’s lease, mourned William Shakespeare more than 400 years ago in one of his most quoted sonnets, “has all too short a date.” Not for much longer. Thanks to global heating, by the close of the century the longer summers arriving by then may have been extended to almost six months.

The lengthening of the northern hemisphere summer has already begun, according to a new study in the journal Geophysical Research Letters. The four seasons are normally defined as calendar events, pinned to the progress of a tilted planet in its annual orbit of the sun.

But Chinese scientists took a simpler approach. They defined summer’s commencement as the onset of temperatures in the hottest 25% of the year, winter by the coming of the coldest 25%.

And then they looked at the temperature data to work out what had already happened, and what is likely to happen as global average temperatures rise, in response to ever-higher greenhouse gas emissions linked to fossil fuel combustion and forest destruction.

They found that in 1952, summer could be counted as 78 days long; by 2011, this had stretched to 95 days in the northern hemisphere. Winter contracted from 76 to 73 days in duration. Spring had dwindled from 124 days to 115; autumn from 87 to 82 days.

Health risk

And if this trend continues, and humans go on burning fossil fuels under the notorious “business as usual” scenario, then by 2100 spring and autumn will go on diminishing, and winter will be over in just two months. Summer will however have been extended to nearly half the year.

“The changing seasonal clock,” the scientists write, “signifies disturbed agriculture seasons and rhythm of species activities, more frequent heat waves, storms and wildfires, amounting to increased risks to humanity.”

The findings will present no immediate surprise to farmers, nor to phenologists, those scientists who have spent a lifetime observing changes in the timing of the natural order: the first buds, the first leaves and flowers, the arrival of insects and migrating birds, all of them affected by the increasingly early arrival of spring.

The abbreviation of winter may not however make the natural world more fecund or productive: many crops and a very large number of deciduous trees rely for health and strength on a reliable period of winter chill, and a shorter winter is inevitably going to be a warmer one.

Conversely a long hot summer is unlikely to be particularly welcome: these will arrive with more intense, more enduring and more extensive heat waves, to pose a threat to both harvests and to human health for perhaps a billion or more people.

“The changing seasonal clock signifies disturbed agriculture seasons,  more frequent heat waves, storms and wildfires, amounting to increased risks to humanity”

The researchers warn that longer, hotter summers will affect the capacity to produce energy while at the same time accelerating demand for electricity to power air-conditioning systems.

Longer summers mean more stress for plants and for forests, more and larger wildfires and health hazards for outdoor workers.

Higher temperatures have been linked to high crime rates in some parts of the US and − the researchers warn − earlier and colder spring seasons can mean more “false springs” followed by severe frosts of the kind that, in 2012 in Michigan, cost fruit growers more than $500,000 in crop
losses.

In yet a further caution they say that virus-bearing mosquitos will have a wider range and longer breeding seasons, to produce sudden outbreaks of disease in regions once considered safe. Those sensitive to plant pollen will find the season of sneezes has suddenly got a lot longer.

“As global warming intensifies, the four seasons of a year no longer have equal months, and their onsets are irregular,” the authors write. This change of seasonal lengths, they add. can trigger a chain of reactions, and “policy-making for agricultural management, health care, and disaster prevention requires adjustment.” − 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

Extreme drought and fire risk may double by 2060

Climate change may soon double the impact of extreme drought and fire. And it’s a two-way traffic.

LONDON, 25 January, 2021 − As climate change threatens a doubling of the impact of extreme drought and fire within a generation, researchers are uncovering the influence of human activity on both these growing risks.

One study has found that human numbers exposed to the hazard of extreme drought are likely to double in the decades to come, as global heating bakes away the groundwater and limits annual snowfall.

Another team of researchers says the risks of extreme wildfire could also rise twofold in the next 40 years in the Mediterranean, southern Africa, eastern North America and the Amazon. In those places already severely scorched by frequent fire − western North America, equatorial Africa, south-east Asia and Australia − hazards could rise by 50%.

And a third, separate study warns that global temperature rise will shift the patterns of rainfall around the tropics − with the consequent risks to tropical crop harvests and to equatorial ecosystems such as rainforest and savannah.

All three studies are reminders of the intricacies of the planetary climate system and the impact of human action in the last hundred years.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this will affect food security and escalate human migration and conflict.”

An international research team reports in the journal Nature Climate Change that it looked at the simple problem of global terrestrial water storage: all the moisture in the canopies of forest trees, in the mountain snows and ice, in the lakes, rivers, wetlands, and in the soil itself.

This wealth of stored water is a big player in the patterns of global flooding and drought in the monsoon climates and the arid lands alike. But, the researchers say, there has so far been no study of the potential impact of global climate change on global terrestrial water storage overall.

So researchers from the US, China, Japan and Europe began modelling tomorrow’s world. And they found that, while 3% of the planet’s people were vulnerable to extreme drought in the timespan from 1976 to 2005, later in the century this proportion could increase to 7% or even 8%.

“More and more people will suffer from extreme droughts if a medium-to-high level of global warming continues and water management is maintained in its present state,” warned Yadu Pokhrel, an engineer at Michigan State University, who led the research.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this increase in water scarcity will affect food security and escalate human migration and conflict.”

Fire chances increased

Australia is a southern hemisphere country that knows about water scarcity: its wildfires in 2019 broke all records and sent a vast cloud of smoke to an altitude of 35 kms.

And, on the evidence of a new study in the journal Nature Communications, it won’t be the last such extreme event. Californian scientists, struck by the scale and intensity of Californian wildfires in 2017 and 2018, report that they took a closer look at the way greenhouse gas emissions and human land use change have played into the risks of extreme fire weather.

The simple act of setting forests afire to clear land for farm use has amplified the risk of extreme blazes in the Amazon and North America by 30% in the last century. Fires create aerosols that could, by absorbing sunlight, help cool the terrain beneath them − in some zones. But they could also affect rainfall levels and raise the chances of fire. The nature of such impacts varies from place to place.

“South-east Asia relies on the monsoon, but aerosols cause so much cooling on land that they can actually suppress a monsoon,” said Danielle Touma of the University of California at Santa Barbara. “It’s not just whether you have aerosols or not, it’s the way the regional climate interacts with aerosols.”

Aerosols − with other forces − cannot just suppress a monsoon, they can shift rain patterns permanently. The tropics, too, have begun to feel the heat of the moment.

Drought stress rises

The footprint of extreme drought and fire is massive. Californian researchers report in Nature Climate Change that, across two thirds of the globe, the tropical rainbelt is likely to shift north over eastern Africa and the Indian Ocean to cause more drought stress in south-eastern Africa and Madagascar and intensified flooding in south Asia.

In the western hemisphere, however, as the Gulf Stream current and the North Atlantic deep water formation weaken, the rain belt could move south to bring greater drought stress to Central America.

And once again, climate change driven by global heating is at work with other human influences to alter what had for most of human history been a stable pattern of climate.

“In Asia, projected reductions in aerosol emissions, glacier melting in the Himalayas and loss of snow cover in northern areas brought on by climate change will cause the atmosphere to heat up faster than in other regions,” said James Randerson of the University of California, Irvine, one of the authors.

“We know the rainbelt shifts towards this heating, and that its northward movement in the eastern hemisphere is consistent with these expected impacts of climate change.” − Climate News Network

Climate change may soon double the impact of extreme drought and fire. And it’s a two-way traffic.

LONDON, 25 January, 2021 − As climate change threatens a doubling of the impact of extreme drought and fire within a generation, researchers are uncovering the influence of human activity on both these growing risks.

One study has found that human numbers exposed to the hazard of extreme drought are likely to double in the decades to come, as global heating bakes away the groundwater and limits annual snowfall.

Another team of researchers says the risks of extreme wildfire could also rise twofold in the next 40 years in the Mediterranean, southern Africa, eastern North America and the Amazon. In those places already severely scorched by frequent fire − western North America, equatorial Africa, south-east Asia and Australia − hazards could rise by 50%.

And a third, separate study warns that global temperature rise will shift the patterns of rainfall around the tropics − with the consequent risks to tropical crop harvests and to equatorial ecosystems such as rainforest and savannah.

All three studies are reminders of the intricacies of the planetary climate system and the impact of human action in the last hundred years.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this will affect food security and escalate human migration and conflict.”

An international research team reports in the journal Nature Climate Change that it looked at the simple problem of global terrestrial water storage: all the moisture in the canopies of forest trees, in the mountain snows and ice, in the lakes, rivers, wetlands, and in the soil itself.

This wealth of stored water is a big player in the patterns of global flooding and drought in the monsoon climates and the arid lands alike. But, the researchers say, there has so far been no study of the potential impact of global climate change on global terrestrial water storage overall.

So researchers from the US, China, Japan and Europe began modelling tomorrow’s world. And they found that, while 3% of the planet’s people were vulnerable to extreme drought in the timespan from 1976 to 2005, later in the century this proportion could increase to 7% or even 8%.

“More and more people will suffer from extreme droughts if a medium-to-high level of global warming continues and water management is maintained in its present state,” warned Yadu Pokhrel, an engineer at Michigan State University, who led the research.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this increase in water scarcity will affect food security and escalate human migration and conflict.”

Fire chances increased

Australia is a southern hemisphere country that knows about water scarcity: its wildfires in 2019 broke all records and sent a vast cloud of smoke to an altitude of 35 kms.

And, on the evidence of a new study in the journal Nature Communications, it won’t be the last such extreme event. Californian scientists, struck by the scale and intensity of Californian wildfires in 2017 and 2018, report that they took a closer look at the way greenhouse gas emissions and human land use change have played into the risks of extreme fire weather.

The simple act of setting forests afire to clear land for farm use has amplified the risk of extreme blazes in the Amazon and North America by 30% in the last century. Fires create aerosols that could, by absorbing sunlight, help cool the terrain beneath them − in some zones. But they could also affect rainfall levels and raise the chances of fire. The nature of such impacts varies from place to place.

“South-east Asia relies on the monsoon, but aerosols cause so much cooling on land that they can actually suppress a monsoon,” said Danielle Touma of the University of California at Santa Barbara. “It’s not just whether you have aerosols or not, it’s the way the regional climate interacts with aerosols.”

Aerosols − with other forces − cannot just suppress a monsoon, they can shift rain patterns permanently. The tropics, too, have begun to feel the heat of the moment.

Drought stress rises

The footprint of extreme drought and fire is massive. Californian researchers report in Nature Climate Change that, across two thirds of the globe, the tropical rainbelt is likely to shift north over eastern Africa and the Indian Ocean to cause more drought stress in south-eastern Africa and Madagascar and intensified flooding in south Asia.

In the western hemisphere, however, as the Gulf Stream current and the North Atlantic deep water formation weaken, the rain belt could move south to bring greater drought stress to Central America.

And once again, climate change driven by global heating is at work with other human influences to alter what had for most of human history been a stable pattern of climate.

“In Asia, projected reductions in aerosol emissions, glacier melting in the Himalayas and loss of snow cover in northern areas brought on by climate change will cause the atmosphere to heat up faster than in other regions,” said James Randerson of the University of California, Irvine, one of the authors.

“We know the rainbelt shifts towards this heating, and that its northward movement in the eastern hemisphere is consistent with these expected impacts of climate change.” − 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

Caspian Sea loss puts Asian water supplies at risk

The Caspian Sea’s decline means a climate-led water crisis for at least five Asian nations as inland seas dry up.

LONDON, 7 January, 2021 − The Caspian Sea − the world’s largest lake − is about to go down in the world. And with it could go the fortunes of some of the people of at least five nations. New research suggests that the Caspian Sea, already getting lower at the rate of several centimetres a year, is to go into even faster decline: later this century, it could be nine metres lower than it is now. Or even 18 metres lower.

In the paradoxical world of climate change, sea levels will rise to threaten coastal settlements, but many of the great inland lakes could be doomed to dwindle.

Dutch and German scientists report in the journal Communications Earth & Environment that because more water will evaporate each summer, and less ice will form each winter, the area of the Caspian − it covers 371,000 square kilometres, an area greater than Japan, or Germany − is doomed to shrink at an accelerating rate.

Lakeside communities, ports and industries in Azerbaijan, Russia, Iran, Turkmenistan and Kazakhstan, all of which border the Caspian, could be left high and dry.

Change required

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded. Fishing boats and container giants alike would struggle, and all the countries of the North Sea would have a huge problem,” said Frank Wesselingh, of the University of Utrecht in the Netherlands, one of the authors. “Here we are talking about a decrease of no less than nine metres, in the best case scenario.”

His co-author Matthias Prange of the University of Bremen in Germany warned that what happens to the Caspian could and will happen to the great land-locked lakes on other continents. “This has to change. We need more studies and a better understanding of the consequences of global warming in this region.”

This is not the first such warning: although much of the world’s concern has been with the dramatic loss of water from the Aral Sea, researchers have worried about the impact of evaporation on the Caspian too. It may be salty, but it is one of the world’s great inland reservoirs of water for industry, agriculture and human settlement.

It is also host to a vast range of species, including the Caspian seal, an endangered creature that depends on winter ice to protect and rear its pups. Its shallow waters provide food for migrating birds, and serve as spawning grounds for its fish, including the sturgeon endemic to the region.

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded, and all the countries of the North Sea would have a huge problem”

The Caspian Sea’s chief source of water is the Volga River: it has no connection with the ocean. So its water levels depend entirely on rainfall, evaporation and inflow. And in a world of global heating, evaporation is on the increase.

The level of rainfall, on the other hand, is likely to decline: in a world of climate change, those already semi-arid regions can expect to become more parched.

The authors expect these challenges will confront not only the dwellers by the Caspian Sea but also those hundreds of millions who live by, and depend upon, other lakes in Asia, and in Africa and North America. The consequences for these people could be just as devastating as global sea level rise will be for others. They call for higher levels of awareness, and an international task force to help address the problem.

“Immediate and co-ordinated action is needed to make up for valuable time lost,” they write. “The shrinking Caspian Sea might serve as a poster child that will help galvanise such actions.” − Climate News Network

The Caspian Sea’s decline means a climate-led water crisis for at least five Asian nations as inland seas dry up.

LONDON, 7 January, 2021 − The Caspian Sea − the world’s largest lake − is about to go down in the world. And with it could go the fortunes of some of the people of at least five nations. New research suggests that the Caspian Sea, already getting lower at the rate of several centimetres a year, is to go into even faster decline: later this century, it could be nine metres lower than it is now. Or even 18 metres lower.

In the paradoxical world of climate change, sea levels will rise to threaten coastal settlements, but many of the great inland lakes could be doomed to dwindle.

Dutch and German scientists report in the journal Communications Earth & Environment that because more water will evaporate each summer, and less ice will form each winter, the area of the Caspian − it covers 371,000 square kilometres, an area greater than Japan, or Germany − is doomed to shrink at an accelerating rate.

Lakeside communities, ports and industries in Azerbaijan, Russia, Iran, Turkmenistan and Kazakhstan, all of which border the Caspian, could be left high and dry.

Change required

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded. Fishing boats and container giants alike would struggle, and all the countries of the North Sea would have a huge problem,” said Frank Wesselingh, of the University of Utrecht in the Netherlands, one of the authors. “Here we are talking about a decrease of no less than nine metres, in the best case scenario.”

His co-author Matthias Prange of the University of Bremen in Germany warned that what happens to the Caspian could and will happen to the great land-locked lakes on other continents. “This has to change. We need more studies and a better understanding of the consequences of global warming in this region.”

This is not the first such warning: although much of the world’s concern has been with the dramatic loss of water from the Aral Sea, researchers have worried about the impact of evaporation on the Caspian too. It may be salty, but it is one of the world’s great inland reservoirs of water for industry, agriculture and human settlement.

It is also host to a vast range of species, including the Caspian seal, an endangered creature that depends on winter ice to protect and rear its pups. Its shallow waters provide food for migrating birds, and serve as spawning grounds for its fish, including the sturgeon endemic to the region.

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded, and all the countries of the North Sea would have a huge problem”

The Caspian Sea’s chief source of water is the Volga River: it has no connection with the ocean. So its water levels depend entirely on rainfall, evaporation and inflow. And in a world of global heating, evaporation is on the increase.

The level of rainfall, on the other hand, is likely to decline: in a world of climate change, those already semi-arid regions can expect to become more parched.

The authors expect these challenges will confront not only the dwellers by the Caspian Sea but also those hundreds of millions who live by, and depend upon, other lakes in Asia, and in Africa and North America. The consequences for these people could be just as devastating as global sea level rise will be for others. They call for higher levels of awareness, and an international task force to help address the problem.

“Immediate and co-ordinated action is needed to make up for valuable time lost,” they write. “The shrinking Caspian Sea might serve as a poster child that will help galvanise such actions.” − Climate News Network

Human handiwork’s mass exceeds world lifeforms

Human handiwork, all we’ve produced, now outweighs the plants and animals evolved over 3 billion years: a global takeover.

LONDON, 10 December, 2020 − Our domination of the planet may have just reached a new level: human handiwork now probably surpasses all that evolution has placed on the Earth. The mass of all the things made by humans − cities, roads, factories, houses, cars, trains, machines, bricks, concrete, steel, glass, tile, asphalt and so on − may have just overtaken the mass of all the living things on the planet.

Among those living things now being outweighed by buildings and roads are all seven billion-plus people on the planet and all their livestock, their cornfields and rice paddies, orchards and gardens.

This conclusion − open to challenge and difficult to establish with immediate certainty − is a fresh and startling measure of the scale of human change to the planet, and of the speed at which it has happened.

At the beginning of the 20th century, the mass of human-produced infrastructure probably added up to just 3% of the mass of the planet’s living tissue: its forests and savannahs, wetlands and scrub, its mammals, fish, reptiles, amphibians, birds, insects and microbes.

But in the course of little more than a century, says a new study in the journal Nature, two things happened. The human population increased fourfold, and with those numbers so did human demand for manufactured things and built objects.

Forests erased

Humans’ demand for farmland has cleared the wilderness and reduced the overall mass of planetary foliage by about half.

Even though humans use ever more land for crops, the mass of those crops is vastly outweighed by the mass of trees and other forest plants cleared to make room for soy, or maize.

Once the planet was home to 2 trillion tonnes, or 2 teratonnes, of natural vegetable life. Now the tally of the green wilderness has been reduced to about 1 teratonne, according to researchers who have embarked on this global accounting of human profit and natural loss.

But the burden of human-fashioned hardware has been growing at around 30 billion tonnes a year, doubled in mass every 20 years or so, and is now estimated at 1.1 teratonnes.

In effect, a species that now numbers about 7.7 bn, and still adds up to only about 0.01% of global biomass, has quarried, mined, and built over so much of the planet that its infrastructure weighs more than the rest of living creation.

“If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes [3tn tonnes] by 2040 − almost triple the dry biomass on Earth”

Even the output of the plastics industries, at eight billion tonnes, adds up to more than twice the mass of all the planet’s animals.

Conclusions of this kind rest on how measurements are arrived at. And there is room for error. Ron Milo of the Weizmann Institute for Science in Israel and his colleagues settled for estimates of the dry weight of living things − that is, tissue as if without water − and this skews the raw figures, because humans and other animals are around 60% water by weight. If the same estimates were made with wet tissue, then the outcome would be different, but not very different.

If so, Professor Milo and his fellow authors suggest that the great crossover could be happening now, or in the next few years. But equally, human handiwork might already have reached its zenith in the last decade.

Either way, the broad conclusion remains the same. The scale of the takeover of the planet by one species is almost complete, and could be devastating to the rest of the natural world.

“The study provides a sort of ‘big picture’ snapshot of the planet in 2020. This overview can provide a crucial understanding of our major role in shaping the face of the Earth in the current age of the Anthropocene,” Professor Milo said.

“The message to both the policy makers and the general public is that we cannot dismiss our role as a tiny one in comparison to the huge Earth. We are already a major player and I think with that comes a shared responsibility.”

Rollcall of devastation

This study is yet another in a long series that demonstrates the now-overwhelming impact of human handiwork upon the environment in which they evolved. Two years ago Professor Milo and colleagues made estimates of the mass of all things living on planet Earth, and confirmed that humans probably outweighed by a factor of ten the mass of all other living wild mammals.

Another team tried to calculate the mass of the human technosphere − once again, all the things humans have ever made − and reached a figure of 30 trillion tonnes.

In the course of the last century or so, profligate human use of fossil fuels may have precipitated a new climate regime, halted the cycle of Ice Ages and reversed a 50 million-year cooling trend.

Geologists who argue that human handiwork has now shifted the planet into a new geological epoch − one still unofficially known as the Anthropocene − have compiled a devastating catalogue of change to the natural world. Other groups have also highlighted the human appropriation of the planet’s land and water, and its toll upon millions of other species with which humanity shares the sunlight.

Professor Milo and his colleagues settled for a more simple illustration. They reckon that for the last five years, humans have been accumulating anthropogenic mass − roads and buildings − at the rate of 30 billion tonnes a year. This is as if every person on the planet produced more than his or her own bodyweight in tarmac and bricks, cement and steel, every week.

They warn: “If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes by 2040 − almost triple the dry biomass on Earth.” − Climate News Network

Human handiwork, all we’ve produced, now outweighs the plants and animals evolved over 3 billion years: a global takeover.

LONDON, 10 December, 2020 − Our domination of the planet may have just reached a new level: human handiwork now probably surpasses all that evolution has placed on the Earth. The mass of all the things made by humans − cities, roads, factories, houses, cars, trains, machines, bricks, concrete, steel, glass, tile, asphalt and so on − may have just overtaken the mass of all the living things on the planet.

Among those living things now being outweighed by buildings and roads are all seven billion-plus people on the planet and all their livestock, their cornfields and rice paddies, orchards and gardens.

This conclusion − open to challenge and difficult to establish with immediate certainty − is a fresh and startling measure of the scale of human change to the planet, and of the speed at which it has happened.

At the beginning of the 20th century, the mass of human-produced infrastructure probably added up to just 3% of the mass of the planet’s living tissue: its forests and savannahs, wetlands and scrub, its mammals, fish, reptiles, amphibians, birds, insects and microbes.

But in the course of little more than a century, says a new study in the journal Nature, two things happened. The human population increased fourfold, and with those numbers so did human demand for manufactured things and built objects.

Forests erased

Humans’ demand for farmland has cleared the wilderness and reduced the overall mass of planetary foliage by about half.

Even though humans use ever more land for crops, the mass of those crops is vastly outweighed by the mass of trees and other forest plants cleared to make room for soy, or maize.

Once the planet was home to 2 trillion tonnes, or 2 teratonnes, of natural vegetable life. Now the tally of the green wilderness has been reduced to about 1 teratonne, according to researchers who have embarked on this global accounting of human profit and natural loss.

But the burden of human-fashioned hardware has been growing at around 30 billion tonnes a year, doubled in mass every 20 years or so, and is now estimated at 1.1 teratonnes.

In effect, a species that now numbers about 7.7 bn, and still adds up to only about 0.01% of global biomass, has quarried, mined, and built over so much of the planet that its infrastructure weighs more than the rest of living creation.

“If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes [3tn tonnes] by 2040 − almost triple the dry biomass on Earth”

Even the output of the plastics industries, at eight billion tonnes, adds up to more than twice the mass of all the planet’s animals.

Conclusions of this kind rest on how measurements are arrived at. And there is room for error. Ron Milo of the Weizmann Institute for Science in Israel and his colleagues settled for estimates of the dry weight of living things − that is, tissue as if without water − and this skews the raw figures, because humans and other animals are around 60% water by weight. If the same estimates were made with wet tissue, then the outcome would be different, but not very different.

If so, Professor Milo and his fellow authors suggest that the great crossover could be happening now, or in the next few years. But equally, human handiwork might already have reached its zenith in the last decade.

Either way, the broad conclusion remains the same. The scale of the takeover of the planet by one species is almost complete, and could be devastating to the rest of the natural world.

“The study provides a sort of ‘big picture’ snapshot of the planet in 2020. This overview can provide a crucial understanding of our major role in shaping the face of the Earth in the current age of the Anthropocene,” Professor Milo said.

“The message to both the policy makers and the general public is that we cannot dismiss our role as a tiny one in comparison to the huge Earth. We are already a major player and I think with that comes a shared responsibility.”

Rollcall of devastation

This study is yet another in a long series that demonstrates the now-overwhelming impact of human handiwork upon the environment in which they evolved. Two years ago Professor Milo and colleagues made estimates of the mass of all things living on planet Earth, and confirmed that humans probably outweighed by a factor of ten the mass of all other living wild mammals.

Another team tried to calculate the mass of the human technosphere − once again, all the things humans have ever made − and reached a figure of 30 trillion tonnes.

In the course of the last century or so, profligate human use of fossil fuels may have precipitated a new climate regime, halted the cycle of Ice Ages and reversed a 50 million-year cooling trend.

Geologists who argue that human handiwork has now shifted the planet into a new geological epoch − one still unofficially known as the Anthropocene − have compiled a devastating catalogue of change to the natural world. Other groups have also highlighted the human appropriation of the planet’s land and water, and its toll upon millions of other species with which humanity shares the sunlight.

Professor Milo and his colleagues settled for a more simple illustration. They reckon that for the last five years, humans have been accumulating anthropogenic mass − roads and buildings − at the rate of 30 billion tonnes a year. This is as if every person on the planet produced more than his or her own bodyweight in tarmac and bricks, cement and steel, every week.

They warn: “If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes by 2040 − almost triple the dry biomass on Earth.” − Climate News Network

Mixed farming beats intensive agriculture methods

It sounds like the conservationist’s dream. But a return to traditional mixed farming ways could pay off for farmers too.

LONDON, 23 November, 2020 − Once again, researchers have shown that it should be possible to feed the human race and leave enough space for the rest of creation, simply by going back to centuries-old mixed farming practices.

That would mean an end to highly intensively-farmed landscapes composed of vast fields that were home to just one crop, and a return to a number of once-traditional husbandry methods. It sounds counter-intuitive, but European researchers are convinced that it could be good value.

They report in the journal Science Advances that they looked at more than 5,000 studies that made more than 40,000 comparisons between what they term diversified and simplified agriculture.

And they found that crop yield in general either kept to the same level or even increased when farmers adopted what they called diversified practices of the kind that sustained subsistence farmers for many centuries.

These include intercropping − different crops side by side − and multiple crops in rotation, strips of flowers to encourage pollinating insects, lower levels of disturbance of the soil and hedges, and forested shelter belts to encourage wildlife alongside farmland.

“Most often, diversification practices resulted in win-win support of services and crop yields”

The payoff? Better ecosystem services such as pollination, the regulation of crop pests by natural enemies, a more efficient turnover of nutrients, higher water quality, and in many cases better storage of carbon in ways that could mitigate climate change.

This, of course, is not how big agribusiness delivers much of the world’s food.

“The trend is that we are simplifying major cropping systems worldwide,” said Giovanni Tamburini, an ecologist at the Swedish University of Agricultural Sciences in Uppsala, who led the study.

“We grow monoculture on enlarged fields in homogenised landscapes. According to our study, diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself.”

It’s an old argument. Is it better for a farmer to invest all in one vast crop of maize or wheat or soy, regularly nourished by commercial fertilisers, routinely sprayed to suppress pests, moulds and mildews, with the land ploughed and harrowed after harvest for the next crop, and always at risk of frost or flood, locust swarms, drought or blight?

All-round winners

Or would it be better in the long run for the farmer to spread the risk by changing and multiplying the crops, and to rely more on undisturbed soils and local habitats for birds and insects that would demolish some of the pests (and of course take some of the crop)?

Researchers have repeatedly argued that both to contain climate change and to preserve the natural world from which all human nourishment and almost all human wealth ultimately derive, farming practices must change, and so must human appetite. The argument remains: what is the best way to set about change down on the farm itself?

There have already been a large number of studies of this question. There have also been meta-analyses, or studies of collected studies. Dr Tamburini and his colleagues identified 41,946 comparisons embedded in 5,160 original studies. They also found 98 meta-analyses. And they took a fresh look at the whole lot to identify what could be win-win, trade-off and lose-lose outcomes.

They found that diversification is better for biodiversity, pollination, pest control, nutrient cycling, soil fertility and water regulation at least 63% of the time. “Most often, diversification practices resulted in win-win support of services and crop yields,” they report.

“Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.” − Climate News Network

It sounds like the conservationist’s dream. But a return to traditional mixed farming ways could pay off for farmers too.

LONDON, 23 November, 2020 − Once again, researchers have shown that it should be possible to feed the human race and leave enough space for the rest of creation, simply by going back to centuries-old mixed farming practices.

That would mean an end to highly intensively-farmed landscapes composed of vast fields that were home to just one crop, and a return to a number of once-traditional husbandry methods. It sounds counter-intuitive, but European researchers are convinced that it could be good value.

They report in the journal Science Advances that they looked at more than 5,000 studies that made more than 40,000 comparisons between what they term diversified and simplified agriculture.

And they found that crop yield in general either kept to the same level or even increased when farmers adopted what they called diversified practices of the kind that sustained subsistence farmers for many centuries.

These include intercropping − different crops side by side − and multiple crops in rotation, strips of flowers to encourage pollinating insects, lower levels of disturbance of the soil and hedges, and forested shelter belts to encourage wildlife alongside farmland.

“Most often, diversification practices resulted in win-win support of services and crop yields”

The payoff? Better ecosystem services such as pollination, the regulation of crop pests by natural enemies, a more efficient turnover of nutrients, higher water quality, and in many cases better storage of carbon in ways that could mitigate climate change.

This, of course, is not how big agribusiness delivers much of the world’s food.

“The trend is that we are simplifying major cropping systems worldwide,” said Giovanni Tamburini, an ecologist at the Swedish University of Agricultural Sciences in Uppsala, who led the study.

“We grow monoculture on enlarged fields in homogenised landscapes. According to our study, diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself.”

It’s an old argument. Is it better for a farmer to invest all in one vast crop of maize or wheat or soy, regularly nourished by commercial fertilisers, routinely sprayed to suppress pests, moulds and mildews, with the land ploughed and harrowed after harvest for the next crop, and always at risk of frost or flood, locust swarms, drought or blight?

All-round winners

Or would it be better in the long run for the farmer to spread the risk by changing and multiplying the crops, and to rely more on undisturbed soils and local habitats for birds and insects that would demolish some of the pests (and of course take some of the crop)?

Researchers have repeatedly argued that both to contain climate change and to preserve the natural world from which all human nourishment and almost all human wealth ultimately derive, farming practices must change, and so must human appetite. The argument remains: what is the best way to set about change down on the farm itself?

There have already been a large number of studies of this question. There have also been meta-analyses, or studies of collected studies. Dr Tamburini and his colleagues identified 41,946 comparisons embedded in 5,160 original studies. They also found 98 meta-analyses. And they took a fresh look at the whole lot to identify what could be win-win, trade-off and lose-lose outcomes.

They found that diversification is better for biodiversity, pollination, pest control, nutrient cycling, soil fertility and water regulation at least 63% of the time. “Most often, diversification practices resulted in win-win support of services and crop yields,” they report.

“Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.” − Climate News Network