Tag Archives: Temperature rise

Global warming: Human activity is the cause

Fresh studies have again confirmed a vital fact about global warming: human activity is its cause. Science questions its own findings, which is why we should trust it.

LONDON, 29 May, 2019 − British scientists have re-asserted an essential reality about global warming: human activity, not slow-acting and so far unidentified natural cycles in the world’s oceans, is its cause.

That activity – including ever-increasing combustion of fossil fuels as well as the devastation of the natural forest – is enough to account for almost all the warming over the last century.

Researchers from the University of Oxford report in the Journal of Climate that they looked at all the available observed land and ocean temperature data since 1850.

They matched this not just with greenhouse gas concentrations but also with records of volcanic eruptions, solar activity and air pollution peaks – all of which affect temperature readings.

“This sounds boring, but sometimes boring results are important”

And their analysis once again confirms a finding first proposed in the 19th century by the Swedish Nobel Laureate Svante Arrhenius: that greenhouse gases are enough to explain the big picture of a slowly but inexorably heating world. Slow-acting global oceanic cycles would have had little or no influence.

“Our study showed there are no hidden drivers of global mean temperature. The temperature change we observe is due to the drivers we know,” said Friederike Otto of Oxford’s Environmental Change Institute.

“This sounds boring, but sometimes boring results are important.”

Studies of this kind are a reminder of why science may, ultimately, be trusted: it takes nothing for granted. Researchers tend to go back and question their own and each other’s published conclusions. In the case of climate research, this has become almost a nervous tic.

Untidy evidence

But it is necessary because climate science in particular remains a work in progress: we live in a crowded, dynamic world and the evidence is always untidy and sometimes confusing, the interpretation of the data potentially subject to bias, and above all each conclusion is bedevilled by the question: is there something – some feedback, some factor, some actor – nobody has yet spotted?

So studies that confirm the big picture are always welcome, especially one that says: we can find no unknown factors. That is why boring results are important. It means that what humans do will change the outcome.

“In this case, it means we will not see any surprises when these drivers – such as gas emissions − change,” said Dr Otto.

“In good news, this means that when greenhouse concentrations go down, temperatures will do so as predicted; the bad news is there is nothing that saves us from temperatures going up as forecasted if we fail drastically to cut greenhouse gas emissions.” − Climate News Network

Fresh studies have again confirmed a vital fact about global warming: human activity is its cause. Science questions its own findings, which is why we should trust it.

LONDON, 29 May, 2019 − British scientists have re-asserted an essential reality about global warming: human activity, not slow-acting and so far unidentified natural cycles in the world’s oceans, is its cause.

That activity – including ever-increasing combustion of fossil fuels as well as the devastation of the natural forest – is enough to account for almost all the warming over the last century.

Researchers from the University of Oxford report in the Journal of Climate that they looked at all the available observed land and ocean temperature data since 1850.

They matched this not just with greenhouse gas concentrations but also with records of volcanic eruptions, solar activity and air pollution peaks – all of which affect temperature readings.

“This sounds boring, but sometimes boring results are important”

And their analysis once again confirms a finding first proposed in the 19th century by the Swedish Nobel Laureate Svante Arrhenius: that greenhouse gases are enough to explain the big picture of a slowly but inexorably heating world. Slow-acting global oceanic cycles would have had little or no influence.

“Our study showed there are no hidden drivers of global mean temperature. The temperature change we observe is due to the drivers we know,” said Friederike Otto of Oxford’s Environmental Change Institute.

“This sounds boring, but sometimes boring results are important.”

Studies of this kind are a reminder of why science may, ultimately, be trusted: it takes nothing for granted. Researchers tend to go back and question their own and each other’s published conclusions. In the case of climate research, this has become almost a nervous tic.

Untidy evidence

But it is necessary because climate science in particular remains a work in progress: we live in a crowded, dynamic world and the evidence is always untidy and sometimes confusing, the interpretation of the data potentially subject to bias, and above all each conclusion is bedevilled by the question: is there something – some feedback, some factor, some actor – nobody has yet spotted?

So studies that confirm the big picture are always welcome, especially one that says: we can find no unknown factors. That is why boring results are important. It means that what humans do will change the outcome.

“In this case, it means we will not see any surprises when these drivers – such as gas emissions − change,” said Dr Otto.

“In good news, this means that when greenhouse concentrations go down, temperatures will do so as predicted; the bad news is there is nothing that saves us from temperatures going up as forecasted if we fail drastically to cut greenhouse gas emissions.” − Climate News Network

No more climate change: it’s now a crisis

What’s in a name? A lot, The Guardian says: it’s ditching mentions of climate change and switching to sterner language.

LONDON, 24 May, 2019 − Talk about climate change, and there’s a good chance that people will know what you’re referring to, even if they don’t share your concerns about it.

But for one UK-based newspaper, The Guardian, “climate change” is now frowned upon, though it’s not formally banned. The paper’s house style guide recommends that its journalists should instead use such terms as “climate crisis” and “global heating”.

The Guardian has updated the style guide to introduce terms that it thinks more accurately describe the environmental crises confronting the world. So out goes “climate change”, to be replaced by the preferred terms, “climate emergency, crisis or breakdown”. “Global heating” replaces “global warming”.

“We want to ensure that we are being scientifically precise, while also communicating clearly with readers on this very important issue,” says the editor-in-chief, Katharine Viner. “The phrase ‘climate change’, for example, sounds rather passive and gentle when what scientists are talking about is a catastrophe for humanity.”

“The climate crisis is no longer a future problem – we need to tackle it now, and every day matters”

The United Nations secretary-general, António Guterres, spoke of a “climate crisis” last September, adding: “We face a direct existential threat.” The climate scientist Professor Hans Joachim Schellnhuber, a former adviser to Angela Merkel, the EU and the pope, also uses the term.

In December Professor Richard Betts, who leads the UK Met Office’s climate research, said “global heating” was a more accurate term than “global warming” to describe what is now happening. British Members of Parliament recently endorsed the opposition Labour Party’s declaration of a climate emergency.

The scale of the climate and wildlife crises has been starkly spelt out by two chilling reports from the world’s scientists. In October 2018 they said carbon emissions must halve by 2030 to avoid even greater risks of drought, floods, extreme heat and poverty for hundreds of millions of people. In May 2019 they said human society is at risk from the accelerating annihilation of wildlife and destruction of the ecosystems that support all life on Earth.

Frequent errors

Other terms have also been updated by the Guardian. It now refers to “wildlife” rather than “biodiversity”, “fish populations” instead of “fish stocks”, and “climate science denier” rather than “climate sceptic”.

The BBC has put a formal end to a practice widely used for 30 years: it accepted last September that it gets coverage of climate change “wrong too often”, telling its staff: “You do not need a ‘denier’ to balance the debate.”

Greta Thunberg, the Swedish teenager who has inspired school strikes for the climate around the globe, said recently: “It’s 2019. Can we all now call it what it is: climate breakdown, climate crisis, climate emergency, ecological breakdown, ecological crisis and ecological emergency?”

The update to the Guardian’s style guide follows the recent addition of the global carbon dioxide level to its daily weather pages. “Levels of CO2 in the atmosphere have risen so dramatically – including a measure of that in our daily weather report is symbolic of what human activity is doing to our climate,” said Katharine Viner at the time.

Daily reminders

“People need reminding that the climate crisis is no longer a future problem – we need to tackle it now, and every day matters.”

The Guardian provides thorough coverage of the global environment, objective reporting and informed and pointed comment. The Climate News Network has since its start been part of the Guardian Environment Network.  The newspaper is one of the best-respected and most widely used international sources of information on the crises of the climate and the natural world.

Many of its competitors will be keen to see what difference in people’s perceptions of the crises follow from the name changes, and whether clearer and more deliberately assertive language prompts bolder action.

“Scientists, the media, and policymakers must, of course, distinguish when we’re talking about the fact of what’s happening (‘climate change’) from the opinion about how bad it is (‘climate crisis’),” Peter Gleick, a climate scientist who co-founded the Pacific Institute, told the US-based Earther website in an email.

Facts – and opinions

“Perhaps that’s a minor quibble, but when I speak in public, I try hard to present the ‘facts’ about climate change and then make clear those facts inform my opinion about how bad the problem is, and will be (we face a ‘climate crisis’).”

Several decades ago people didn’t talk much about climate change: they knew what was happening as global warming. When that was junked, to recognise that some parts of the globe were actually cooling as others warmed, it was certainly a move to something more scientifically accurate.

Climate deniers, though, said that there was no evidence of warming, and that by using the phrase “climate change” scientists were admitting that they had got the science wrong.

Remember the no-nonsense approach of the nursery rhyme character Humpty Dumpty: “When I use a word, it means just what I choose it to mean − neither more nor less.” Words can be slippery, and dangerous. − Climate News Network

What’s in a name? A lot, The Guardian says: it’s ditching mentions of climate change and switching to sterner language.

LONDON, 24 May, 2019 − Talk about climate change, and there’s a good chance that people will know what you’re referring to, even if they don’t share your concerns about it.

But for one UK-based newspaper, The Guardian, “climate change” is now frowned upon, though it’s not formally banned. The paper’s house style guide recommends that its journalists should instead use such terms as “climate crisis” and “global heating”.

The Guardian has updated the style guide to introduce terms that it thinks more accurately describe the environmental crises confronting the world. So out goes “climate change”, to be replaced by the preferred terms, “climate emergency, crisis or breakdown”. “Global heating” replaces “global warming”.

“We want to ensure that we are being scientifically precise, while also communicating clearly with readers on this very important issue,” says the editor-in-chief, Katharine Viner. “The phrase ‘climate change’, for example, sounds rather passive and gentle when what scientists are talking about is a catastrophe for humanity.”

“The climate crisis is no longer a future problem – we need to tackle it now, and every day matters”

The United Nations secretary-general, António Guterres, spoke of a “climate crisis” last September, adding: “We face a direct existential threat.” The climate scientist Professor Hans Joachim Schellnhuber, a former adviser to Angela Merkel, the EU and the pope, also uses the term.

In December Professor Richard Betts, who leads the UK Met Office’s climate research, said “global heating” was a more accurate term than “global warming” to describe what is now happening. British Members of Parliament recently endorsed the opposition Labour Party’s declaration of a climate emergency.

The scale of the climate and wildlife crises has been starkly spelt out by two chilling reports from the world’s scientists. In October 2018 they said carbon emissions must halve by 2030 to avoid even greater risks of drought, floods, extreme heat and poverty for hundreds of millions of people. In May 2019 they said human society is at risk from the accelerating annihilation of wildlife and destruction of the ecosystems that support all life on Earth.

Frequent errors

Other terms have also been updated by the Guardian. It now refers to “wildlife” rather than “biodiversity”, “fish populations” instead of “fish stocks”, and “climate science denier” rather than “climate sceptic”.

The BBC has put a formal end to a practice widely used for 30 years: it accepted last September that it gets coverage of climate change “wrong too often”, telling its staff: “You do not need a ‘denier’ to balance the debate.”

Greta Thunberg, the Swedish teenager who has inspired school strikes for the climate around the globe, said recently: “It’s 2019. Can we all now call it what it is: climate breakdown, climate crisis, climate emergency, ecological breakdown, ecological crisis and ecological emergency?”

The update to the Guardian’s style guide follows the recent addition of the global carbon dioxide level to its daily weather pages. “Levels of CO2 in the atmosphere have risen so dramatically – including a measure of that in our daily weather report is symbolic of what human activity is doing to our climate,” said Katharine Viner at the time.

Daily reminders

“People need reminding that the climate crisis is no longer a future problem – we need to tackle it now, and every day matters.”

The Guardian provides thorough coverage of the global environment, objective reporting and informed and pointed comment. The Climate News Network has since its start been part of the Guardian Environment Network.  The newspaper is one of the best-respected and most widely used international sources of information on the crises of the climate and the natural world.

Many of its competitors will be keen to see what difference in people’s perceptions of the crises follow from the name changes, and whether clearer and more deliberately assertive language prompts bolder action.

“Scientists, the media, and policymakers must, of course, distinguish when we’re talking about the fact of what’s happening (‘climate change’) from the opinion about how bad it is (‘climate crisis’),” Peter Gleick, a climate scientist who co-founded the Pacific Institute, told the US-based Earther website in an email.

Facts – and opinions

“Perhaps that’s a minor quibble, but when I speak in public, I try hard to present the ‘facts’ about climate change and then make clear those facts inform my opinion about how bad the problem is, and will be (we face a ‘climate crisis’).”

Several decades ago people didn’t talk much about climate change: they knew what was happening as global warming. When that was junked, to recognise that some parts of the globe were actually cooling as others warmed, it was certainly a move to something more scientifically accurate.

Climate deniers, though, said that there was no evidence of warming, and that by using the phrase “climate change” scientists were admitting that they had got the science wrong.

Remember the no-nonsense approach of the nursery rhyme character Humpty Dumpty: “When I use a word, it means just what I choose it to mean − neither more nor less.” Words can be slippery, and dangerous. − Climate News Network

Crops at risk from changing climate

Global warming could bring yet more challenges to a hungry world. New studies have identified precise ways in which a changing climate puts crops at risk.

LONDON, 14 May, 2019 – Climate change is leaving crops at risk. Driven by global warming – and with it ever greater extremes of heat, drought and rainfall – the rising mercury can explain up to half of all variations in harvest yields worldwide.

Unusually cold nights, ever greater numbers of extremely hot summer days, weeks with no rainfall, or torrents of storm-driven precipitation, account for somewhere between a fifth to 49% of yield losses for maize, rice, spring wheat and soy beans.

And once international scientists had eliminated the effect of temperature averages across the whole growing season, they still found that heatwaves, drought and torrential downfall accounted for 18% to 43% of losses.

In a second study, US researchers have a warning for the Midwest’s maize farmers: too much rain is just as bad for the harvest as too much heat and a long dry spell.

“While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption … making it critical for food security”

In a third study, British researchers have identified a new climate hazard for one of the tropical world’s staples: climate change has heightened the risk of a devastating fungal infection that is already ravaging banana plantations in Latin America and the Caribbean.

The impact of climate change driven by global warming fuelled by profligate fossil fuel use had been worrying ministries and agricultural researchers for years: more carbon dioxide should and sometimes could mean a greener world.

More warmth and earlier springs mean a longer growing season with lower risks of late frost. A warmer atmosphere can hold more moisture, which means ultimately more rainfall.

But the average rise in temperature worldwide of just 1°C in the last century is exactly that: an average. What cities and countryside have observed is an increase both in the number and intensity of potentially lethal heatwaves, of longer and more frequent parching in those landscapes that are normally dry, with heavier downpours in places that can depend on reliable rainfall.

Knowledge allows preparation

In Europe, the US and Africa, researchers have started to measure the cost to the grains, pulses and tubers that feed 7.7 billion people now, and will have to feed 9bn later this century.

Scientists in Australia, Germany, Spain, Switzerland and the US report in the journal Environmental Research Letters that they developed a machine-learning algorithm to make sense of climate data and harvest data collected worldwide from 1961 to 2008.

The aim was to isolate the factors within climate change that might affect harvests, on the principle that if farmers know the hazards, they can prepare.

“Interestingly, we found that the most important climate factors for yield anomalies were related to temperature, not precipitation, as one could expect, with average growing season temperature and temperature extremes playing a dominant role in predicting crop yields,” said Elisabeth Vogel of the University of Melbourne, who led the study.

Big picture reached

Nowhere was this more visible than in the figures for maize yield in Africa. “While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption – compared to just 3% in North America – making it critical for food security in the region.”

Dr Vogel and her colleagues looked at crop yields, mean seasonal temperatures, extremes and regions to arrive at their big picture. But impacts of extremes vary according to region, soil, latitude and other factors too.

US scientists report in the journal Global Change Biology that yield statistics and crop insurance data from 1981 to 2016 on the Midwest maize harvest told them a slightly different story. In some years excessive rain reduced the corn yield by as much as 34%; drought and heat in turn could be linked to losses of 37%. It depended on where the crop was grown.

“As rainfall becomes more extreme, crop insurance needs to evolve to better meet planting challenges faced by farmers,” said Gary Schnitkey of the University of Urbana-Champaign, one of the authors.

Bananas in danger

And British scientists report in the Philosophical Transactions of the Royal Society B that changes in temperature and moisture linked to global warming could be bad for the banana crop.

These have increased the risk of infection by the fungus Pseudocercospora fijiensis, or Black Sigatoka disease, by more than 44% in Latin America and the Caribbean. The disease can reduce yield in infected plants by up to 80%.

“Climate change has made temperatures better for spore germination and growth, and made crop canopies wetter, raising the risk of Black Sigatoka infection in many banana-growing areas of Latin America,” said Daniel Bebber, of the University of Exeter.

“While fungus is likely to have been introduced to Honduras on plants imported from Asia for breeding research, our models indicate that climate change over the past 60 years has exacerbated its impact.” – Climate News Network

Global warming could bring yet more challenges to a hungry world. New studies have identified precise ways in which a changing climate puts crops at risk.

LONDON, 14 May, 2019 – Climate change is leaving crops at risk. Driven by global warming – and with it ever greater extremes of heat, drought and rainfall – the rising mercury can explain up to half of all variations in harvest yields worldwide.

Unusually cold nights, ever greater numbers of extremely hot summer days, weeks with no rainfall, or torrents of storm-driven precipitation, account for somewhere between a fifth to 49% of yield losses for maize, rice, spring wheat and soy beans.

And once international scientists had eliminated the effect of temperature averages across the whole growing season, they still found that heatwaves, drought and torrential downfall accounted for 18% to 43% of losses.

In a second study, US researchers have a warning for the Midwest’s maize farmers: too much rain is just as bad for the harvest as too much heat and a long dry spell.

“While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption … making it critical for food security”

In a third study, British researchers have identified a new climate hazard for one of the tropical world’s staples: climate change has heightened the risk of a devastating fungal infection that is already ravaging banana plantations in Latin America and the Caribbean.

The impact of climate change driven by global warming fuelled by profligate fossil fuel use had been worrying ministries and agricultural researchers for years: more carbon dioxide should and sometimes could mean a greener world.

More warmth and earlier springs mean a longer growing season with lower risks of late frost. A warmer atmosphere can hold more moisture, which means ultimately more rainfall.

But the average rise in temperature worldwide of just 1°C in the last century is exactly that: an average. What cities and countryside have observed is an increase both in the number and intensity of potentially lethal heatwaves, of longer and more frequent parching in those landscapes that are normally dry, with heavier downpours in places that can depend on reliable rainfall.

Knowledge allows preparation

In Europe, the US and Africa, researchers have started to measure the cost to the grains, pulses and tubers that feed 7.7 billion people now, and will have to feed 9bn later this century.

Scientists in Australia, Germany, Spain, Switzerland and the US report in the journal Environmental Research Letters that they developed a machine-learning algorithm to make sense of climate data and harvest data collected worldwide from 1961 to 2008.

The aim was to isolate the factors within climate change that might affect harvests, on the principle that if farmers know the hazards, they can prepare.

“Interestingly, we found that the most important climate factors for yield anomalies were related to temperature, not precipitation, as one could expect, with average growing season temperature and temperature extremes playing a dominant role in predicting crop yields,” said Elisabeth Vogel of the University of Melbourne, who led the study.

Big picture reached

Nowhere was this more visible than in the figures for maize yield in Africa. “While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption – compared to just 3% in North America – making it critical for food security in the region.”

Dr Vogel and her colleagues looked at crop yields, mean seasonal temperatures, extremes and regions to arrive at their big picture. But impacts of extremes vary according to region, soil, latitude and other factors too.

US scientists report in the journal Global Change Biology that yield statistics and crop insurance data from 1981 to 2016 on the Midwest maize harvest told them a slightly different story. In some years excessive rain reduced the corn yield by as much as 34%; drought and heat in turn could be linked to losses of 37%. It depended on where the crop was grown.

“As rainfall becomes more extreme, crop insurance needs to evolve to better meet planting challenges faced by farmers,” said Gary Schnitkey of the University of Urbana-Champaign, one of the authors.

Bananas in danger

And British scientists report in the Philosophical Transactions of the Royal Society B that changes in temperature and moisture linked to global warming could be bad for the banana crop.

These have increased the risk of infection by the fungus Pseudocercospora fijiensis, or Black Sigatoka disease, by more than 44% in Latin America and the Caribbean. The disease can reduce yield in infected plants by up to 80%.

“Climate change has made temperatures better for spore germination and growth, and made crop canopies wetter, raising the risk of Black Sigatoka infection in many banana-growing areas of Latin America,” said Daniel Bebber, of the University of Exeter.

“While fungus is likely to have been introduced to Honduras on plants imported from Asia for breeding research, our models indicate that climate change over the past 60 years has exacerbated its impact.” – Climate News Network

Arctic soils may produce huge methane leak

Arctic soils tell an ominous story. Change in the high latitudes could be swifter and more devastating than anyone had imagined.

LONDON, 9 May, 2019 − The permafrost may be about to spring an unwelcome surprise, with Arctic soils thought to be thawing faster than anyone had predicted. This threatens to release vast quantities of frozen methane into the atmosphere and transform the northern landscape.

One-fourth of all the land in the northern half of the globe is defined as permafrost. This long-frozen soil is home to the detritus of life over many thousands of years: the remains of plants, animals and microbes. The permanently frozen soils of the region hold, so far in a harmless state, 1,600 billion tonnes of carbon: twice as much as exists in the atmosphere.

And as the Arctic warms, this could release ever-greater volumes of a potent greenhouse gas, to accelerate global warming still further, and the consequent collapse of the soil, the flooding and the landslides could change not just the habitat but even the contours of the high latitudes.

“We are watching this sleeping giant wake up right in front of our eyes,” said Merritt Turetsky, an ecologist at the University of Guelph in Canada.

“Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north”

“We work in areas where permafrost contains a lot of ice, and our field sites are being destroyed by abrupt collapse of this ice, not gradually over decades, but very quickly over months to years.”

And Miriam Jones, of the US Geological Survey, said: “This abrupt thaw is changing forested ecosystems to thaw lakes and wetlands, resulting in a wholesale transformation of the landscape that not only impacts carbon feedbacks to climate but is also altering wildlife habitat and damaging infrastructure.”

The two scientists are among 14 researchers who argue in the journal Nature that the thaw is happening far faster than anyone had predicted. The Arctic is warming at a rate faster than almost anywhere else on Earth.

So far the thaw affects less than one-fifth of the entire permafrost, but even this relatively small area has the potential to double what climate scientists call “feedback” – the release of hitherto stored greenhouse gases to fuel yet faster warming.

Growing urgency

It is the latest in a series of increasingly urgent warnings about the rate of change in the Arctic.

Stable climate patterns are maintained by stable temperatures. As the polar north warms twice as fast as the average for the rest of the world, the all-important difference between tropics and polar regions begins to accelerate the advance of spring, and delay the next freeze to bring weather extremes and ever higher sea level rises which could soon start to exact a toll on human economies on an unprecedented scale.

Researchers have been warning for years about the consequences of thaw and the release of ever more carbon into the greenhouse atmosphere.

But it is only in recent months that climate scientists have begun to see the effect of ice melt at depth upon the soils that – for now – support Arctic roads, buildings and pipelines as well as a huge natural ecosystem of plants and animals adapted by thousands of years of evolution to long winters and brief flowering summers.

Goal in jeopardy

Put simply: 195 nations met in Paris in 2015 and agreed  to contain average global warming to “well below” 2°C above the long-term level for most of human history. Accelerating thaw in the Arctic puts that goal at risk.

The researchers call for better and more reliable observation of change in the region, more investment in on-the-ground measurement of change, more information about the extent of carbon emissions from the soils, better models of global change in the region, and better reporting of change.

“We can’t prevent abrupt thawing of the permafrost, but we can try to forecast where and when it is likely to happen, to enable decision makers and communities to protect people and resources”, the scientists write.

“Reducing global emissions might be the surest way to slow further release of permafrost carbon into the atmosphere. Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north.” − Climate News Network

Arctic soils tell an ominous story. Change in the high latitudes could be swifter and more devastating than anyone had imagined.

LONDON, 9 May, 2019 − The permafrost may be about to spring an unwelcome surprise, with Arctic soils thought to be thawing faster than anyone had predicted. This threatens to release vast quantities of frozen methane into the atmosphere and transform the northern landscape.

One-fourth of all the land in the northern half of the globe is defined as permafrost. This long-frozen soil is home to the detritus of life over many thousands of years: the remains of plants, animals and microbes. The permanently frozen soils of the region hold, so far in a harmless state, 1,600 billion tonnes of carbon: twice as much as exists in the atmosphere.

And as the Arctic warms, this could release ever-greater volumes of a potent greenhouse gas, to accelerate global warming still further, and the consequent collapse of the soil, the flooding and the landslides could change not just the habitat but even the contours of the high latitudes.

“We are watching this sleeping giant wake up right in front of our eyes,” said Merritt Turetsky, an ecologist at the University of Guelph in Canada.

“Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north”

“We work in areas where permafrost contains a lot of ice, and our field sites are being destroyed by abrupt collapse of this ice, not gradually over decades, but very quickly over months to years.”

And Miriam Jones, of the US Geological Survey, said: “This abrupt thaw is changing forested ecosystems to thaw lakes and wetlands, resulting in a wholesale transformation of the landscape that not only impacts carbon feedbacks to climate but is also altering wildlife habitat and damaging infrastructure.”

The two scientists are among 14 researchers who argue in the journal Nature that the thaw is happening far faster than anyone had predicted. The Arctic is warming at a rate faster than almost anywhere else on Earth.

So far the thaw affects less than one-fifth of the entire permafrost, but even this relatively small area has the potential to double what climate scientists call “feedback” – the release of hitherto stored greenhouse gases to fuel yet faster warming.

Growing urgency

It is the latest in a series of increasingly urgent warnings about the rate of change in the Arctic.

Stable climate patterns are maintained by stable temperatures. As the polar north warms twice as fast as the average for the rest of the world, the all-important difference between tropics and polar regions begins to accelerate the advance of spring, and delay the next freeze to bring weather extremes and ever higher sea level rises which could soon start to exact a toll on human economies on an unprecedented scale.

Researchers have been warning for years about the consequences of thaw and the release of ever more carbon into the greenhouse atmosphere.

But it is only in recent months that climate scientists have begun to see the effect of ice melt at depth upon the soils that – for now – support Arctic roads, buildings and pipelines as well as a huge natural ecosystem of plants and animals adapted by thousands of years of evolution to long winters and brief flowering summers.

Goal in jeopardy

Put simply: 195 nations met in Paris in 2015 and agreed  to contain average global warming to “well below” 2°C above the long-term level for most of human history. Accelerating thaw in the Arctic puts that goal at risk.

The researchers call for better and more reliable observation of change in the region, more investment in on-the-ground measurement of change, more information about the extent of carbon emissions from the soils, better models of global change in the region, and better reporting of change.

“We can’t prevent abrupt thawing of the permafrost, but we can try to forecast where and when it is likely to happen, to enable decision makers and communities to protect people and resources”, the scientists write.

“Reducing global emissions might be the surest way to slow further release of permafrost carbon into the atmosphere. Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north.” − Climate News Network

Heat makes ocean winds and waves fiercer

The seas are rising. Ocean winds and waves are growing in speed and force. The oceans could be feeling the heat.

LONDON, 1 May, 2019 − The great swells of the Pacific are beginning to swell even more as fiercer ocean winds and waves leave their mark. The breakers that crash on the storm beaches now do so with greater force. The white horses are gathering pace.

A 33-year-study of data from 31 satellites and 80 ocean buoys has confirmed suspicions. The extreme ocean winds are now fiercer, and the waves are getting measurably higher.

It is a given of global warming that as average planetary temperatures rise, then more energy is available for storm, rainfall and drought.

In the past century, because of ever-increasing combustion of fossil fuels that release growing quantities of greenhouse gases, average global temperatures have crept higher by 1°C and in three decades the speed of extreme winds in the Southern Ocean has increased by 8%, or 1.5 metres per second. Extreme waves have increased by 30cms, or 5%, over the same period.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk”

“Although increases of 5 and 8% might not seem like much, if sustained into the future such changes to our climate will have major impacts,” said Ian Young, an engineer at the University of Melbourne in Australia

He and a colleague report in the journal Science that they reached their conclusion on the basis of 4 billion observations made between 1985 and 2018.

“Flooding events are caused by storm surge and associated breaking waves. The increased sea level makes these events more serious and more frequent,” said Professor Young. “Increases in wave height, and changes in other properties such as wave direction, will further increase the probability of coastal flooding.”

Sea levels have been creeping ever higher, in large part because of the retreat of most of the planet’s great glaciers and the ever-increasing meltwater from Greenland and West Antarctica, and also as a simple matter of physics: as the oceans warm, the waters become less dense and sea levels rise.

Difficult measurements

Surfers and pleasure-seekers began to worry about the impact of global warming and climate change on wave patterns years ago. But seemingly simple phenomena such as the effects wave height and wind speed have in the open oceans on a world-wide basis are harder to measure.

Spanish oceanographers reported earlier this year that they were sure that ocean waves were gathering in force and strength, and European engineers have warned of the impact of more intense storms backed up by rising seas on the Atlantic ports and coastlines of the continent.

But there are problems: precision measurements have been made only recently. Oceanographers cannot be sure that they are not witnessing a natural cycle of ocean change, in which storm intensities slowly vary over a pattern of decades.

Since 1985 earth observation satellites have been equipped with altimeters to measure wave height and wind speed, radiometers to measure wind speed, and scatterometers to record wind speed and direction. The next problem has been calibrating data from a range of different satellites, and indeed the slightly different stories told by instruments on the same satellite.

Worse to come

But the Australian engineers report that they are now 90% confident that they can measure ocean change: violent storms now arrive with higher wave crests and more dangerous winds than they did in 1985, and although this is true worldwide, the effect is most pronounced in the great ocean that swirls around Antarctica.

The next challenge is to make estimates of how much more violent the worst sea storms are likely to become later in the century, as planetary average temperatures – and sea levels – continue to rise.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk,” Professor Young said.

“We need a better understanding of how much this change is due to long-term climate change, and how much is due to multi-decadal fluctuations or cycles.” − Climate News Network

The seas are rising. Ocean winds and waves are growing in speed and force. The oceans could be feeling the heat.

LONDON, 1 May, 2019 − The great swells of the Pacific are beginning to swell even more as fiercer ocean winds and waves leave their mark. The breakers that crash on the storm beaches now do so with greater force. The white horses are gathering pace.

A 33-year-study of data from 31 satellites and 80 ocean buoys has confirmed suspicions. The extreme ocean winds are now fiercer, and the waves are getting measurably higher.

It is a given of global warming that as average planetary temperatures rise, then more energy is available for storm, rainfall and drought.

In the past century, because of ever-increasing combustion of fossil fuels that release growing quantities of greenhouse gases, average global temperatures have crept higher by 1°C and in three decades the speed of extreme winds in the Southern Ocean has increased by 8%, or 1.5 metres per second. Extreme waves have increased by 30cms, or 5%, over the same period.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk”

“Although increases of 5 and 8% might not seem like much, if sustained into the future such changes to our climate will have major impacts,” said Ian Young, an engineer at the University of Melbourne in Australia

He and a colleague report in the journal Science that they reached their conclusion on the basis of 4 billion observations made between 1985 and 2018.

“Flooding events are caused by storm surge and associated breaking waves. The increased sea level makes these events more serious and more frequent,” said Professor Young. “Increases in wave height, and changes in other properties such as wave direction, will further increase the probability of coastal flooding.”

Sea levels have been creeping ever higher, in large part because of the retreat of most of the planet’s great glaciers and the ever-increasing meltwater from Greenland and West Antarctica, and also as a simple matter of physics: as the oceans warm, the waters become less dense and sea levels rise.

Difficult measurements

Surfers and pleasure-seekers began to worry about the impact of global warming and climate change on wave patterns years ago. But seemingly simple phenomena such as the effects wave height and wind speed have in the open oceans on a world-wide basis are harder to measure.

Spanish oceanographers reported earlier this year that they were sure that ocean waves were gathering in force and strength, and European engineers have warned of the impact of more intense storms backed up by rising seas on the Atlantic ports and coastlines of the continent.

But there are problems: precision measurements have been made only recently. Oceanographers cannot be sure that they are not witnessing a natural cycle of ocean change, in which storm intensities slowly vary over a pattern of decades.

Since 1985 earth observation satellites have been equipped with altimeters to measure wave height and wind speed, radiometers to measure wind speed, and scatterometers to record wind speed and direction. The next problem has been calibrating data from a range of different satellites, and indeed the slightly different stories told by instruments on the same satellite.

Worse to come

But the Australian engineers report that they are now 90% confident that they can measure ocean change: violent storms now arrive with higher wave crests and more dangerous winds than they did in 1985, and although this is true worldwide, the effect is most pronounced in the great ocean that swirls around Antarctica.

The next challenge is to make estimates of how much more violent the worst sea storms are likely to become later in the century, as planetary average temperatures – and sea levels – continue to rise.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk,” Professor Young said.

“We need a better understanding of how much this change is due to long-term climate change, and how much is due to multi-decadal fluctuations or cycles.” − Climate News Network

Extreme heat is growing threat to harvests

A warmer world means more chance of extreme heat in more than one continent at the same time, and a rising threat to global food security.

LONDON, 17 April, 2019 − Ever-higher average global temperatures mean more intense extreme heat over ever-wider regions.

When the planet becomes on average 1.5°C warmer than it was for most of human history, then for two out of every three years, one-fourth of the northern hemisphere will experience the kind of blistering heat waves recorded in 2018.

And should planetary average temperatures creep up by 2°C – the maximum proposed by 195 nations at the global climate conference in Paris in 2015 – then the probability rises to 100%. That is, extreme heat over a large area of the hemisphere will be guaranteed every summer.

Heat extremes are all too often accompanied by devastating thunderstorms or extended drought and massive outbreaks of wildfire, with potentially disastrous consequences for harvests in the blighted regions.

“Ultimately, extreme events affecting large areas of the planet could threaten food supply elsewhere, even in Switzerland”

In 2018, people died of heatstroke, roads and even rails started to melt, forests went up in flames, and power generation systems sometimes failed, not just in one region but in a number in the temperate zones and the Arctic at the same time.

Between May and July, 22% of agricultural land and crowded cities of the northern half of the globe were hit simultaneously by extended periods of extreme heat. In all, 17 countries were affected, from Canada and the US across the Atlantic and Pacific to Russia, Japan and South Korea. In Europe, temperatures in the rivers Rhine and Elbe reached such heights that fish suffocated; there were wildfires in Sweden, Latvia and Greece and record temperatures in Germany.

“Without climate change that can be explained by human activity, we wouldn’t have such a large area being simultaneously affected by heat as we did in 2018,” said Martha Vogel, of the Swiss Federal Institute of Technology, known as ETH Zurich, who presented her findings at a press conference held by the European Geosciences Union in Vienna.

Serious impacts

The reasoning and methodology have yet to be published, but the authors say their paper is in review for the journal Earth’s Future. “If in future more and more key agricultural regions and densely populated areas are affected by simultaneous heatwaves, this would have severe consequences.”

Other research teams have already warned that global warming could bring a repeat of the simultaneous drought and heat outbreaks across the world that triggered calamitous famines in Asia and Africa between 1875 and 1878.

They have repeatedly warned of potentially catastrophic levels of heat that could arrive with increasing frequency to claim greater numbers of lives especially when accompanied by extreme levels of humidity.

The Swiss scientists focussed on data from agricultural regions and busy urban areas above latitude 30° for the years 1958 to 2018 to find occasions of heat extremes in more than one region and then used computer modelling to simulate probabilities as average planetary temperatures continued to grow.

Poor are hardest-hit

The choice of agricultural areas was purposeful: in such scenarios where more than one region suffers harvest failures, food prices begin to soar. In the 2010 heatwave, Russia ended all its wheat exports and prices in Pakistan rose by 16%, with harsh consequences for the poorest. Governments, agriculture ministries and international aid agencies need to be prepared.

“Such incidents cannot be resolved by individual countries acting on their own. Ultimately, extreme events affecting large areas of the planet could threaten food supply elsewhere, even in Switzerland,” said Sonia Seneviratne, an ETH climate scientist who has also shared in the study.

“We are already clearly feeling the effects just from the one degree that global average temperature has risen since the pre-industrial era.” − Climate News Network

A warmer world means more chance of extreme heat in more than one continent at the same time, and a rising threat to global food security.

LONDON, 17 April, 2019 − Ever-higher average global temperatures mean more intense extreme heat over ever-wider regions.

When the planet becomes on average 1.5°C warmer than it was for most of human history, then for two out of every three years, one-fourth of the northern hemisphere will experience the kind of blistering heat waves recorded in 2018.

And should planetary average temperatures creep up by 2°C – the maximum proposed by 195 nations at the global climate conference in Paris in 2015 – then the probability rises to 100%. That is, extreme heat over a large area of the hemisphere will be guaranteed every summer.

Heat extremes are all too often accompanied by devastating thunderstorms or extended drought and massive outbreaks of wildfire, with potentially disastrous consequences for harvests in the blighted regions.

“Ultimately, extreme events affecting large areas of the planet could threaten food supply elsewhere, even in Switzerland”

In 2018, people died of heatstroke, roads and even rails started to melt, forests went up in flames, and power generation systems sometimes failed, not just in one region but in a number in the temperate zones and the Arctic at the same time.

Between May and July, 22% of agricultural land and crowded cities of the northern half of the globe were hit simultaneously by extended periods of extreme heat. In all, 17 countries were affected, from Canada and the US across the Atlantic and Pacific to Russia, Japan and South Korea. In Europe, temperatures in the rivers Rhine and Elbe reached such heights that fish suffocated; there were wildfires in Sweden, Latvia and Greece and record temperatures in Germany.

“Without climate change that can be explained by human activity, we wouldn’t have such a large area being simultaneously affected by heat as we did in 2018,” said Martha Vogel, of the Swiss Federal Institute of Technology, known as ETH Zurich, who presented her findings at a press conference held by the European Geosciences Union in Vienna.

Serious impacts

The reasoning and methodology have yet to be published, but the authors say their paper is in review for the journal Earth’s Future. “If in future more and more key agricultural regions and densely populated areas are affected by simultaneous heatwaves, this would have severe consequences.”

Other research teams have already warned that global warming could bring a repeat of the simultaneous drought and heat outbreaks across the world that triggered calamitous famines in Asia and Africa between 1875 and 1878.

They have repeatedly warned of potentially catastrophic levels of heat that could arrive with increasing frequency to claim greater numbers of lives especially when accompanied by extreme levels of humidity.

The Swiss scientists focussed on data from agricultural regions and busy urban areas above latitude 30° for the years 1958 to 2018 to find occasions of heat extremes in more than one region and then used computer modelling to simulate probabilities as average planetary temperatures continued to grow.

Poor are hardest-hit

The choice of agricultural areas was purposeful: in such scenarios where more than one region suffers harvest failures, food prices begin to soar. In the 2010 heatwave, Russia ended all its wheat exports and prices in Pakistan rose by 16%, with harsh consequences for the poorest. Governments, agriculture ministries and international aid agencies need to be prepared.

“Such incidents cannot be resolved by individual countries acting on their own. Ultimately, extreme events affecting large areas of the planet could threaten food supply elsewhere, even in Switzerland,” said Sonia Seneviratne, an ETH climate scientist who has also shared in the study.

“We are already clearly feeling the effects just from the one degree that global average temperature has risen since the pre-industrial era.” − Climate News Network

Rapidly rising heat will cut maize harvests

Soon the corn could roast on the cob long before the maize harvests are due. That could be far sooner than anyone expects.

LONDON, 3 April, 2019 − European scientists have bad news for the world’s farmers: within a decade, maize harvests will suffer as global temperatures will have reached a level that will turn the once-in-a-decade extremes of heat and drought into the new normal.

That will mean that the worst production losses ever felt by the maize farmers will happen with increasing frequency, if global planetary temperatures reach 1.5°C above the long-term average for almost all human history.

The world is already 1°C hotter on average than it was before the Industrial Revolution and its increasing dependence on fossil fuels to power the global economies.

And if the temperature reaches 2°C, researchers warn, farmlands where maize once flourished will be hit by heat and drought events never before experienced. The big agribusiness giants will be hurt – and so will the small subsistence farmers who depend on their crop to keep their families alive.

“At the 2°C warning level . . . our projections suggest that global maize production will suffer from unprecedented losses”

Already the warming in the last few decades has begun to hit yields: the scientists reckon that maize yield within the 28 European member states is 290,000 tonnes a year lower than it would have been without global warming.

Significantly, 195 nations met in Paris in 2015 to agree to co-operate to keep average global warming down to if possible “well below” 2°C by 2100. Their target was a rise of no more than 1.5°C.

At the present rate of action – to switch to solar and wind power, to restore the world’s forests – the planet is on course to warm by 3°C by the close of the century.

But a new study by the European Union’s Joint Research Centre in Ispra, Italy, published in the journal Earth’s Future, is not worried about the average, but about the extremes that, over the course of a year, make up that average, and drive up the loss of one particular crop: maize.

Vulnerabilities

Maize is now the world’s biggest single crop: the US is the most important producer but the EU ranks fourth in the world, producing an average of 65 million tonnes a year for food and cattle fodder. This warm climate crop is at certain points in its growing season vulnerable to heat stress and to drought. And heat stress seems increasingly  certain.

Researchers have warned, repeatedly, that higher average planetary or regional temperatures will mean increasingly intense, frequent, prolonged and potentially dangerous extremes of heat. And those areas already vulnerable to drought are likely to see much more of it, while other regions will become more at risk of catastrophic flood.

Agricultural scientists have already confirmed that untimely spells of heat and drought have started to slash cereal yields as measured across whole regions, or per field.

Hunger warning

And although the US has increased production, this too will be vulnerable to further warming. The World Meteorological Organisation has just warned of an already warmer, hungrier world.

The European researchers report that their analysis of past and future maize production surveys a range of outcomes: in one of these, the worst could start to happen as early as 2020. They suggest greater efforts to meet the goals set in Paris but even with those, farmers and agriculture ministries will need to find ways to adapt.

Their report ends bluntly. “We found that global warming will substantially increase the risk of maize production losses in most world regions, including the United States. The climatic events affecting historical global maize production once every 10 years will become normal at the 1.5°C global warming level, which is reached in the 2020s in most of the analysed climate model simulations,” they write.

“At the 2°C warning level (approximately late 2030s) our projections suggest that global maize production will suffer from unprecedented losses.” − Climate News Network

Soon the corn could roast on the cob long before the maize harvests are due. That could be far sooner than anyone expects.

LONDON, 3 April, 2019 − European scientists have bad news for the world’s farmers: within a decade, maize harvests will suffer as global temperatures will have reached a level that will turn the once-in-a-decade extremes of heat and drought into the new normal.

That will mean that the worst production losses ever felt by the maize farmers will happen with increasing frequency, if global planetary temperatures reach 1.5°C above the long-term average for almost all human history.

The world is already 1°C hotter on average than it was before the Industrial Revolution and its increasing dependence on fossil fuels to power the global economies.

And if the temperature reaches 2°C, researchers warn, farmlands where maize once flourished will be hit by heat and drought events never before experienced. The big agribusiness giants will be hurt – and so will the small subsistence farmers who depend on their crop to keep their families alive.

“At the 2°C warning level . . . our projections suggest that global maize production will suffer from unprecedented losses”

Already the warming in the last few decades has begun to hit yields: the scientists reckon that maize yield within the 28 European member states is 290,000 tonnes a year lower than it would have been without global warming.

Significantly, 195 nations met in Paris in 2015 to agree to co-operate to keep average global warming down to if possible “well below” 2°C by 2100. Their target was a rise of no more than 1.5°C.

At the present rate of action – to switch to solar and wind power, to restore the world’s forests – the planet is on course to warm by 3°C by the close of the century.

But a new study by the European Union’s Joint Research Centre in Ispra, Italy, published in the journal Earth’s Future, is not worried about the average, but about the extremes that, over the course of a year, make up that average, and drive up the loss of one particular crop: maize.

Vulnerabilities

Maize is now the world’s biggest single crop: the US is the most important producer but the EU ranks fourth in the world, producing an average of 65 million tonnes a year for food and cattle fodder. This warm climate crop is at certain points in its growing season vulnerable to heat stress and to drought. And heat stress seems increasingly  certain.

Researchers have warned, repeatedly, that higher average planetary or regional temperatures will mean increasingly intense, frequent, prolonged and potentially dangerous extremes of heat. And those areas already vulnerable to drought are likely to see much more of it, while other regions will become more at risk of catastrophic flood.

Agricultural scientists have already confirmed that untimely spells of heat and drought have started to slash cereal yields as measured across whole regions, or per field.

Hunger warning

And although the US has increased production, this too will be vulnerable to further warming. The World Meteorological Organisation has just warned of an already warmer, hungrier world.

The European researchers report that their analysis of past and future maize production surveys a range of outcomes: in one of these, the worst could start to happen as early as 2020. They suggest greater efforts to meet the goals set in Paris but even with those, farmers and agriculture ministries will need to find ways to adapt.

Their report ends bluntly. “We found that global warming will substantially increase the risk of maize production losses in most world regions, including the United States. The climatic events affecting historical global maize production once every 10 years will become normal at the 1.5°C global warming level, which is reached in the 2020s in most of the analysed climate model simulations,” they write.

“At the 2°C warning level (approximately late 2030s) our projections suggest that global maize production will suffer from unprecedented losses.” − Climate News Network

Ocean heatwaves drive more fish north

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

Paris climate pledge would help world fishing

Honouring the Paris climate pledge would provide a fair catch for the world’s fishing fleets. Warm up the oceans, though, and everyone loses.

LONDON, 12 March, 2019 – Canadian scientists have worked out the way to make the most of the world’s fish stocks: by honouring the Paris climate pledge.

Seagoing nations could raise revenues for their fishing fleets, put more seafood on the table and protect the most valuable commercial fish stocks simply by doing what they had promised in 2015 to do anyway.

The key is the historic agreement reached then in Paris by 195 nations, to take steps to limit average global warming to “well below” a total of 2°C above the long-term average for most of human history, and to do this by 2100.

In the last century or so the global temperature has already risen by around 1°C, as a consequence of ever-increasing combustion of fossil fuels that emit greenhouse gases into the atmosphere.

“The largest gains will occur in developing country waters … which are at the greatest risk due to warming temperatures”

But although the world agreed its ideal target, the action so far leaves it on course for a potentially catastrophic rise of 3.5°C by the end of the century.

“Achieving the Agreement’s target could increase global fisheries revenues by $4.6 billion annually, seafood workers’ income by $3.7 bn and reduce household seafood expenditures by $5.4 bn,” said Rashid Sumaila, of the University of British Columbia’s Institute for Oceans and Fisheries.

“The largest gains will occur in developing country waters, such as Kiribati, the Maldives and Indonesia, which are at the greatest risk due to warming temperatures and rely the most on fish for food security, incomes and employment.”

What the researchers did – they explain their approach in the journal Science Advances – was to match what the computer forecasts said the Paris target would deliver, with what might happen if the world went on burning oil, coal and gas under the notorious business-as-usual scenario.

Impacts on ecosystems

They looked at the impact of less or more warming on 381 marine species, including the 10 that generate the most money, and they included ecosystem consequences as well as the economic payoff promised by the Paris target.

Their conclusion is that three-fourths of maritime countries would benefit, with the largest gains to be made by the developing nations.

Under the Paris scenario, the total mass of the fish species that generate the highest revenues would increase globally by 6.5%, with an 8.4% increase in the waters of developing countries. Overall, developed countries would see a marginal fall of 0.4%.

The Paris option would see an additional 3.3 million tonnes landed sustainably every year, compared with the business-as-usual scenario.

Conservation also needed

The British Columbia scientists are not the first to make the case for Paris in terms of fishery revenues: US and Japanese scientists looked at the same problem last year and concluded that the Paris option – matched by careful conservation approaches – could yield more fish for the hungry, and more revenues for the fishermen, if the ocean temperatures were kept from rising too dangerously.

But all the signals so far are ominous. A warmer world means a stormier one and greater danger for fishing fleets. More carbon dioxide in the atmosphere means ever more acidic seas, which seems to affect fish behaviour and threaten marine habitats such as coral reefs and kelp forests.

The same rise in carbon dioxide will warm the oceans and drive fish to migrate. Overall, humans have already left the seas diminished, and worse could be on the way. Fishing and seafood support an estimated 260 million full-time and part-time jobs worldwide.

Many to benefit

The Science Advances study is a reminder that while change is inexorable, the worst need not be inevitable. All continents except Europe would benefit from implementation of the Paris Agreement.

But as fish move towards the poles, countries in northern Europe might benefit from greater choice in their waters, and losses in the overall catch might be buffered by hjgher prices for those fish actually landed.

Russia could see catches reduced by as much as 25% under the 1.5°C target rather than the 3.5°C forecast. “However a projected 19% increase in fish prices, known as the price effect, should result in a negligible loss of less than 2% in fisheries revenues in Russia,” said William Cheung, one of the co-authors, of the University of British Columbia.

“Conversely, for the US fishing revenues are expected to decrease by 8% due to price effects but will be offset by a 21% increase in catch potential.” – Climate News Network

Honouring the Paris climate pledge would provide a fair catch for the world’s fishing fleets. Warm up the oceans, though, and everyone loses.

LONDON, 12 March, 2019 – Canadian scientists have worked out the way to make the most of the world’s fish stocks: by honouring the Paris climate pledge.

Seagoing nations could raise revenues for their fishing fleets, put more seafood on the table and protect the most valuable commercial fish stocks simply by doing what they had promised in 2015 to do anyway.

The key is the historic agreement reached then in Paris by 195 nations, to take steps to limit average global warming to “well below” a total of 2°C above the long-term average for most of human history, and to do this by 2100.

In the last century or so the global temperature has already risen by around 1°C, as a consequence of ever-increasing combustion of fossil fuels that emit greenhouse gases into the atmosphere.

“The largest gains will occur in developing country waters … which are at the greatest risk due to warming temperatures”

But although the world agreed its ideal target, the action so far leaves it on course for a potentially catastrophic rise of 3.5°C by the end of the century.

“Achieving the Agreement’s target could increase global fisheries revenues by $4.6 billion annually, seafood workers’ income by $3.7 bn and reduce household seafood expenditures by $5.4 bn,” said Rashid Sumaila, of the University of British Columbia’s Institute for Oceans and Fisheries.

“The largest gains will occur in developing country waters, such as Kiribati, the Maldives and Indonesia, which are at the greatest risk due to warming temperatures and rely the most on fish for food security, incomes and employment.”

What the researchers did – they explain their approach in the journal Science Advances – was to match what the computer forecasts said the Paris target would deliver, with what might happen if the world went on burning oil, coal and gas under the notorious business-as-usual scenario.

Impacts on ecosystems

They looked at the impact of less or more warming on 381 marine species, including the 10 that generate the most money, and they included ecosystem consequences as well as the economic payoff promised by the Paris target.

Their conclusion is that three-fourths of maritime countries would benefit, with the largest gains to be made by the developing nations.

Under the Paris scenario, the total mass of the fish species that generate the highest revenues would increase globally by 6.5%, with an 8.4% increase in the waters of developing countries. Overall, developed countries would see a marginal fall of 0.4%.

The Paris option would see an additional 3.3 million tonnes landed sustainably every year, compared with the business-as-usual scenario.

Conservation also needed

The British Columbia scientists are not the first to make the case for Paris in terms of fishery revenues: US and Japanese scientists looked at the same problem last year and concluded that the Paris option – matched by careful conservation approaches – could yield more fish for the hungry, and more revenues for the fishermen, if the ocean temperatures were kept from rising too dangerously.

But all the signals so far are ominous. A warmer world means a stormier one and greater danger for fishing fleets. More carbon dioxide in the atmosphere means ever more acidic seas, which seems to affect fish behaviour and threaten marine habitats such as coral reefs and kelp forests.

The same rise in carbon dioxide will warm the oceans and drive fish to migrate. Overall, humans have already left the seas diminished, and worse could be on the way. Fishing and seafood support an estimated 260 million full-time and part-time jobs worldwide.

Many to benefit

The Science Advances study is a reminder that while change is inexorable, the worst need not be inevitable. All continents except Europe would benefit from implementation of the Paris Agreement.

But as fish move towards the poles, countries in northern Europe might benefit from greater choice in their waters, and losses in the overall catch might be buffered by hjgher prices for those fish actually landed.

Russia could see catches reduced by as much as 25% under the 1.5°C target rather than the 3.5°C forecast. “However a projected 19% increase in fish prices, known as the price effect, should result in a negligible loss of less than 2% in fisheries revenues in Russia,” said William Cheung, one of the co-authors, of the University of British Columbia.

“Conversely, for the US fishing revenues are expected to decrease by 8% due to price effects but will be offset by a 21% increase in catch potential.” – Climate News Network

Greenland’s winter rain melts icecap faster

Its huge icecap is thawing faster because Greenland’s winter rain means its snows are being washed away, or falling at higher altitudes.

LONDON, 8 March, 2019 − The largest body of ice in the northern hemisphere faces a problem scientists had not identified before: Greenland’s winter rain is accelerating the loss of its vast store of ice.

Two new studies have identified mechanisms for ever-faster melting of the ice. One is that the snowline keeps shifting, to alter the levels of radiation absorbed by the ice sheet that masks the Greenland bedrock.

The other is that ever more snow and ice is simply washed away by the rainfall – even in the Arctic winter. That is because global warming has raised Greenland’s summer temperatures as much as 1.8°C, and by up to 3°C in the winter months.

Reports of winter rain over an icecap large enough – if it were all washed into the ocean – to raise global sea levels by more than seven metres are a surprise: glaciologists expect some melting of the polar ice caps each summer, to be replaced each winter by snowfall that insulates the ice below and then endures for much of the following summer.

Meltwater matters more

Such icecaps are thought to shed most of their mass as glaciers deliver ice downstream to the coast, and icebergs calve and float south.

But research in the journal The Cryosphere tells a different and unexpected story: direct meltwater now running off Greenland into the sea accounts for seven-tenths of the 270 billion tonnes of ice that Greenland loses each year. And increasingly, rainy weather is the trigger that sets off the rivulets of meltwater streaming to the coast.

German and US researchers took data from 20 Greenland weather stations between 1979 and 2012, and matched this with satellite imagery that could distinguish snow from liquid water. In the data they identified more than 300 episodes of melting in which the initial trigger was the arrival of rain.

And during the 33 years of data, they found that melting associated with rainfall doubled during the summer months, and tripled in winter. Nearly a third of all the flow of water from Greenland was initiated by rainfall.

“Suddenly the snowline was just gone. In a couple of days it had moved 30 kilometres or so up the ice sheet”

Warm air can melt ice but, more potently, warming air can turn what might have been snow into rain. Liquid water carries considerable heat, to soak into the snow and melt it. And the clouds that bring the rain have a way of conserving the warmth in the air.

Some of the meltwater will refreeze as surface ice, darkened by dust and colonised by algae, to absorb solar radiation more efficiently than snow, and to melt more easily and much earlier in the summer.

“If it rains in the winter, that preconditions the ice to be more vulnerable in the summer,” said Marco Tedesco of Columbia University’s Lamont-Doherty Earth Observatory, one of the authors. “We are starting to realise you have to look at all the seasons.”

Most of the winter rainfall is in the island’s south and southwest, spilled by warm ocean winds from the south, and these may have become more common because warming has been linked to changes in the stratospheric jet stream.

Loss not gain

Marilena Oltmanns, of Germany’s Geomar Centre for Ocean Research, called the discovery “a surprise to see. The ice should be gaining mass in winter when it snows, but an increasing part of the mass gain from precipitation is lost by melt.”

But research in the journal Science Advances in the same week pinpoints another related factor in setting the rate of melting in Greenland: the snowline.

This varies significantly from year to year. Once again, snow tends to reflect radiation, and with darker ice to absorb it the new study suggests that even Greenland’s icy mountains conform to simple physics.

Researchers flew drones inland across the bare ice to identify the snowline. A pause during a few days of high winds brought a big surprise.

No specific studies

“Suddenly the snowline was just gone. In a couple of days it had moved 30 kilometres or so up the ice sheet and was now out of the range of our drones.

“That was the first moment we thought we should investigate the effects of snowline movement on melt,” said Jonathan Ryan, of Brown University in Rhode Island, who led the study.

And Laurence Smith, a researcher based at Brown University, and one of the authors, said: “People who study alpine glaciers have recognised the importance of snowlines for years, but no one has explicitly studied them in Greenland before.

“This study shows for the first time that simple partitioning between bare ice and snow matters more when it comes to melting than a whole host of other processes that receive more attention.” − Climate News Network

Its huge icecap is thawing faster because Greenland’s winter rain means its snows are being washed away, or falling at higher altitudes.

LONDON, 8 March, 2019 − The largest body of ice in the northern hemisphere faces a problem scientists had not identified before: Greenland’s winter rain is accelerating the loss of its vast store of ice.

Two new studies have identified mechanisms for ever-faster melting of the ice. One is that the snowline keeps shifting, to alter the levels of radiation absorbed by the ice sheet that masks the Greenland bedrock.

The other is that ever more snow and ice is simply washed away by the rainfall – even in the Arctic winter. That is because global warming has raised Greenland’s summer temperatures as much as 1.8°C, and by up to 3°C in the winter months.

Reports of winter rain over an icecap large enough – if it were all washed into the ocean – to raise global sea levels by more than seven metres are a surprise: glaciologists expect some melting of the polar ice caps each summer, to be replaced each winter by snowfall that insulates the ice below and then endures for much of the following summer.

Meltwater matters more

Such icecaps are thought to shed most of their mass as glaciers deliver ice downstream to the coast, and icebergs calve and float south.

But research in the journal The Cryosphere tells a different and unexpected story: direct meltwater now running off Greenland into the sea accounts for seven-tenths of the 270 billion tonnes of ice that Greenland loses each year. And increasingly, rainy weather is the trigger that sets off the rivulets of meltwater streaming to the coast.

German and US researchers took data from 20 Greenland weather stations between 1979 and 2012, and matched this with satellite imagery that could distinguish snow from liquid water. In the data they identified more than 300 episodes of melting in which the initial trigger was the arrival of rain.

And during the 33 years of data, they found that melting associated with rainfall doubled during the summer months, and tripled in winter. Nearly a third of all the flow of water from Greenland was initiated by rainfall.

“Suddenly the snowline was just gone. In a couple of days it had moved 30 kilometres or so up the ice sheet”

Warm air can melt ice but, more potently, warming air can turn what might have been snow into rain. Liquid water carries considerable heat, to soak into the snow and melt it. And the clouds that bring the rain have a way of conserving the warmth in the air.

Some of the meltwater will refreeze as surface ice, darkened by dust and colonised by algae, to absorb solar radiation more efficiently than snow, and to melt more easily and much earlier in the summer.

“If it rains in the winter, that preconditions the ice to be more vulnerable in the summer,” said Marco Tedesco of Columbia University’s Lamont-Doherty Earth Observatory, one of the authors. “We are starting to realise you have to look at all the seasons.”

Most of the winter rainfall is in the island’s south and southwest, spilled by warm ocean winds from the south, and these may have become more common because warming has been linked to changes in the stratospheric jet stream.

Loss not gain

Marilena Oltmanns, of Germany’s Geomar Centre for Ocean Research, called the discovery “a surprise to see. The ice should be gaining mass in winter when it snows, but an increasing part of the mass gain from precipitation is lost by melt.”

But research in the journal Science Advances in the same week pinpoints another related factor in setting the rate of melting in Greenland: the snowline.

This varies significantly from year to year. Once again, snow tends to reflect radiation, and with darker ice to absorb it the new study suggests that even Greenland’s icy mountains conform to simple physics.

Researchers flew drones inland across the bare ice to identify the snowline. A pause during a few days of high winds brought a big surprise.

No specific studies

“Suddenly the snowline was just gone. In a couple of days it had moved 30 kilometres or so up the ice sheet and was now out of the range of our drones.

“That was the first moment we thought we should investigate the effects of snowline movement on melt,” said Jonathan Ryan, of Brown University in Rhode Island, who led the study.

And Laurence Smith, a researcher based at Brown University, and one of the authors, said: “People who study alpine glaciers have recognised the importance of snowlines for years, but no one has explicitly studied them in Greenland before.

“This study shows for the first time that simple partitioning between bare ice and snow matters more when it comes to melting than a whole host of other processes that receive more attention.” − Climate News Network