Tag Archives: Arctic

Climate heat melts Arctic snows and dries forests

Fires now blaze under Arctic snows, where once even the wettest rainforests burned. Climate change delivers unlikely outcomes.

LONDON, 12 October, 2020 − The northern polar region isn’t just warming: it’s also smoking, as the rising heat thaws the Arctic snows. Researchers have identified a new class of fire hazard.

High above the Arctic Circle, fires that flared a year ago continued to smoulder under the snow through the winter to flare up again − two months earlier than usual, and on a scale not seen before.

And if the notion of fire and ice seems a surprise, prepare for the idea of a blazing rainforest. In a second and separate study, researchers exploring the climate lessons from the deep past 90 million years ago have found that, if the atmosphere is rich enough in oxygen, then even the wettest foliage can ignite and burn, to consume perhaps up to 40% of the world’s forest.

Scientists from the US report in Nature Geoscience that they have identified an unexpected threat from “zombie fires” which, despite heavy snowmelt, they say “can smoulder in carbon-rich peat below the surface for months or years, often only detectable through smoke released at the surface, and can even occur through cold winter months.”

“The climate change we are causing now, it’s not something where if we don’t fix it, only our grandkids will have to deal with it. The impacts are really long-lasting”

They warn that in the fast-changing climate of the highest northern latitudes, the evidence from last year and this suggest that extreme temperatures and drier conditions mean there is a lot more surface fuel in the Arctic to catch fire and melt the Arctic snows.

Dwarf shrubs, sedges, mosses and grasses are invading the tundra, to join the surface peat, and even the bogs, fens and marches of the tundra are now burning. In all, 50% of the detected fires above 65°North − many in the Russian Arctic − happened on permafrost: that is, on ever-icy soils.

“It’s not just the amount of burned area that is alarming,” said Merritt Turetsky of the University of Colorado at Boulder, and one of the authors. “There are other trends we noticed in the satellite data that tell us how the Arctic fire regime is changing and what this spells for our climate future.”

Wildfires are on the increase now, in a world in which climate change has delivered hotter and drier conditions for many regions. Unexpectedly, according to a second study in Nature Geoscience, fossilized evidence in rocks in Utah has delivered evidence of massive and sustained forest fires, in the form of polycyclic aromatic hydrocarbons preserved in black shales laid down in the Cretaceous.

Huge absorption rate

Researchers pieced together a story of dramatic climate change 94 million years ago, when carbon dioxide built up in the atmosphere, and land and sea plants began to absorb it from the atmosphere on a massive scale. Microbial respiration stepped up too, and parts of the ocean became increasingly low in oxygen.

During 100,000 years of this, so much carbon had been buried in the ground or the oceans that – with the release of molecular oxygen, the O2 in CO2 − atmospheric oxygen levels began to increase. And with that, the scientists say, so did the probability of forest fires, even in wet forest ecosystems. Altogether, perhaps 30% to 40% of the planet’s forests were consumed by fire over 100 millennia.

“One of the consequences of having more oxygen in the atmosphere is that it’s easier to burn fires. It’s the same reason you blow on embers to stoke a fire,” said Garrett Boudinot, then at the University of Boulder Colorado and now with the Colorado Wildlife Council, who led the research.

“This finding highlights the prolonged impacts of climate change. The climate change we are causing now, it’s not something where if we don’t fix it, only our grandkids will have to deal with it. The history of climate change in Earth history tells us that the impacts are really long-lasting.” − Climate News Network

Fires now blaze under Arctic snows, where once even the wettest rainforests burned. Climate change delivers unlikely outcomes.

LONDON, 12 October, 2020 − The northern polar region isn’t just warming: it’s also smoking, as the rising heat thaws the Arctic snows. Researchers have identified a new class of fire hazard.

High above the Arctic Circle, fires that flared a year ago continued to smoulder under the snow through the winter to flare up again − two months earlier than usual, and on a scale not seen before.

And if the notion of fire and ice seems a surprise, prepare for the idea of a blazing rainforest. In a second and separate study, researchers exploring the climate lessons from the deep past 90 million years ago have found that, if the atmosphere is rich enough in oxygen, then even the wettest foliage can ignite and burn, to consume perhaps up to 40% of the world’s forest.

Scientists from the US report in Nature Geoscience that they have identified an unexpected threat from “zombie fires” which, despite heavy snowmelt, they say “can smoulder in carbon-rich peat below the surface for months or years, often only detectable through smoke released at the surface, and can even occur through cold winter months.”

“The climate change we are causing now, it’s not something where if we don’t fix it, only our grandkids will have to deal with it. The impacts are really long-lasting”

They warn that in the fast-changing climate of the highest northern latitudes, the evidence from last year and this suggest that extreme temperatures and drier conditions mean there is a lot more surface fuel in the Arctic to catch fire and melt the Arctic snows.

Dwarf shrubs, sedges, mosses and grasses are invading the tundra, to join the surface peat, and even the bogs, fens and marches of the tundra are now burning. In all, 50% of the detected fires above 65°North − many in the Russian Arctic − happened on permafrost: that is, on ever-icy soils.

“It’s not just the amount of burned area that is alarming,” said Merritt Turetsky of the University of Colorado at Boulder, and one of the authors. “There are other trends we noticed in the satellite data that tell us how the Arctic fire regime is changing and what this spells for our climate future.”

Wildfires are on the increase now, in a world in which climate change has delivered hotter and drier conditions for many regions. Unexpectedly, according to a second study in Nature Geoscience, fossilized evidence in rocks in Utah has delivered evidence of massive and sustained forest fires, in the form of polycyclic aromatic hydrocarbons preserved in black shales laid down in the Cretaceous.

Huge absorption rate

Researchers pieced together a story of dramatic climate change 94 million years ago, when carbon dioxide built up in the atmosphere, and land and sea plants began to absorb it from the atmosphere on a massive scale. Microbial respiration stepped up too, and parts of the ocean became increasingly low in oxygen.

During 100,000 years of this, so much carbon had been buried in the ground or the oceans that – with the release of molecular oxygen, the O2 in CO2 − atmospheric oxygen levels began to increase. And with that, the scientists say, so did the probability of forest fires, even in wet forest ecosystems. Altogether, perhaps 30% to 40% of the planet’s forests were consumed by fire over 100 millennia.

“One of the consequences of having more oxygen in the atmosphere is that it’s easier to burn fires. It’s the same reason you blow on embers to stoke a fire,” said Garrett Boudinot, then at the University of Boulder Colorado and now with the Colorado Wildlife Council, who led the research.

“This finding highlights the prolonged impacts of climate change. The climate change we are causing now, it’s not something where if we don’t fix it, only our grandkids will have to deal with it. The history of climate change in Earth history tells us that the impacts are really long-lasting.” − Climate News Network

Hotter seas imperil both human and marine life

Climate warming brings hotter seas. The waters mix less. And conditions for some creatures could grow increasingly stifling.

LONDON, 9 October, 2020 − Climate change has led to hotter seas across the world: in 2018 European water temperatures reached record levels, and a marine heatwave in the north-east Pacific devastated marine life.

Less predictably, global heating has made the oceans more stable, with discrete, stratified layers that resist mixing. And that could be very bad news, because it could make the blue water that covers 70% of the planet less effective at absorbing atmospheric heat and thus mitigating climate change.

And ever-warmer sea temperatures could have another unwelcome impact: as temperatures rise, levels of dissolved oxygen fall. And that could make it difficult for some sea creatures to breathe.

The oceans play a vital role in the water, energy and carbon cycles upon which all life depends. In 2010, demographers counted 1.9 billion people living within 100kms of the sea and less than 100 metres above sea level: that is 28% of all humanity. Many of them are crowded into 17 megacities with populations of more than 5 million people each. For many, the sea is the neighbourhood.

European researchers warn, in a new and detailed report on the state of the oceans from 1993 to 2010, that the rise in sea temperatures in the Mediterranean is without precedent, and the largest rise of all has been measured in the Arctic Ocean.

“Human society has always been dependent on the seas. Failure to reach good environmental status for our seas and oceans is not an option”

They also call as a matter of urgency for comprehensive and systematic monitoring of the ocean. “Human society has always been dependent on the seas,” they warn. “Failure to reach good environmental status for our seas and oceans is not an option.”

Chinese and US scientists report in the journal Nature Climate Change that − beyond reports of stronger winds and waves and ever more intense tropical cyclones − the rise in atmospheric temperatures has fundamentally altered oceanic temperatures and salinity, with a paradoxical effect: the seas have become more stable. Warm and therefore less dense surface water lies upon colder, more saline and denser waters at depth, to limit overall mixing.

Since 1960, the upper 2000 metres of the oceans have become 5% more stratified, and the top 150 metres 18% more stratified.

“The same process, global warming, is both making the atmosphere less stable and the oceans more stable. Water near the ocean’s surface is warming faster than the water below. That makes the oceans become more stable,” said Michael Mann of Penn State University in Pennsylvania, one of the team.

“The ability of the oceans to bury heat from the atmosphere and mitigate global warming is made more difficult when the ocean becomes more stratified and there is less mixing. Less downward mixing of warming waters means the ocean surface warms even faster, leading, for example, to more powerful hurricanes. Global climate models underestimate these trends.”

Struggle for survival

Warmer temperatures don’t just make the oceans more stable, they may make living conditions more uncomfortable or even impossible for some of the sea’s citizenry.

US researchers report in the journal Nature that they looked at the physiological challenge of oxygen and energy demands faced by 145 marine species − including shrimps, catsharks and sea squirts − to find that many are already under pressure.

“Organisms today are living right up to the warmest temperatures possible that will supply them with adequate oxygen for their activity level – so higher temperatures are immediately going to affect their ability to get enough oxygen,” said Curtis Deutsch of the University of Washington.

“In response to warming, their activity level is going to be restricted or their habitat is going to start shrinking. It’s not like they are going to be fine and carry on.” − Climate News Network

Climate warming brings hotter seas. The waters mix less. And conditions for some creatures could grow increasingly stifling.

LONDON, 9 October, 2020 − Climate change has led to hotter seas across the world: in 2018 European water temperatures reached record levels, and a marine heatwave in the north-east Pacific devastated marine life.

Less predictably, global heating has made the oceans more stable, with discrete, stratified layers that resist mixing. And that could be very bad news, because it could make the blue water that covers 70% of the planet less effective at absorbing atmospheric heat and thus mitigating climate change.

And ever-warmer sea temperatures could have another unwelcome impact: as temperatures rise, levels of dissolved oxygen fall. And that could make it difficult for some sea creatures to breathe.

The oceans play a vital role in the water, energy and carbon cycles upon which all life depends. In 2010, demographers counted 1.9 billion people living within 100kms of the sea and less than 100 metres above sea level: that is 28% of all humanity. Many of them are crowded into 17 megacities with populations of more than 5 million people each. For many, the sea is the neighbourhood.

European researchers warn, in a new and detailed report on the state of the oceans from 1993 to 2010, that the rise in sea temperatures in the Mediterranean is without precedent, and the largest rise of all has been measured in the Arctic Ocean.

“Human society has always been dependent on the seas. Failure to reach good environmental status for our seas and oceans is not an option”

They also call as a matter of urgency for comprehensive and systematic monitoring of the ocean. “Human society has always been dependent on the seas,” they warn. “Failure to reach good environmental status for our seas and oceans is not an option.”

Chinese and US scientists report in the journal Nature Climate Change that − beyond reports of stronger winds and waves and ever more intense tropical cyclones − the rise in atmospheric temperatures has fundamentally altered oceanic temperatures and salinity, with a paradoxical effect: the seas have become more stable. Warm and therefore less dense surface water lies upon colder, more saline and denser waters at depth, to limit overall mixing.

Since 1960, the upper 2000 metres of the oceans have become 5% more stratified, and the top 150 metres 18% more stratified.

“The same process, global warming, is both making the atmosphere less stable and the oceans more stable. Water near the ocean’s surface is warming faster than the water below. That makes the oceans become more stable,” said Michael Mann of Penn State University in Pennsylvania, one of the team.

“The ability of the oceans to bury heat from the atmosphere and mitigate global warming is made more difficult when the ocean becomes more stratified and there is less mixing. Less downward mixing of warming waters means the ocean surface warms even faster, leading, for example, to more powerful hurricanes. Global climate models underestimate these trends.”

Struggle for survival

Warmer temperatures don’t just make the oceans more stable, they may make living conditions more uncomfortable or even impossible for some of the sea’s citizenry.

US researchers report in the journal Nature that they looked at the physiological challenge of oxygen and energy demands faced by 145 marine species − including shrimps, catsharks and sea squirts − to find that many are already under pressure.

“Organisms today are living right up to the warmest temperatures possible that will supply them with adequate oxygen for their activity level – so higher temperatures are immediately going to affect their ability to get enough oxygen,” said Curtis Deutsch of the University of Washington.

“In response to warming, their activity level is going to be restricted or their habitat is going to start shrinking. It’s not like they are going to be fine and carry on.” − Climate News Network

Greenland’s ice loss likely to hit 12,000-year high

Greenland’s ice loss could be more this century than at any time in the history of civilization − and perhaps much more.

LONDON, 5 October, 2020 − By the end of this century Greenland’s ice loss will probably be higher than in any century during the last 12,000 years.

Even if humans take immediate drastic action to reduce greenhouse gas emissions, this new record loss will happen. And if − as seems the case − nations go on burning ever more fossil fuels and destroying ever more natural forest, then this ice loss will be four times greater than at any period in human history, according to a new study.

US, Canadian and Danish scientists report in the journal Nature that they used geological evidence and detailed computer simulations to model the past and future loss of ice from the northern hemisphere’s biggest land-borne store − Greenland bears enough ice to raise global sea levels by six metres or more − and measure possible rates of change.

On their reckoning, shortly after the end of the last Ice Age around 12,000 years ago, Greenland’s ice loss was up to 6,000 billion tonnes in the course of 100 years. That, for the entire span from then till now, stayed the record.

They calculate that the rate of loss now, based on measurements in the first 18 years of this century, could still be slightly greater, even if the 195 nations that promised in Paris in 2015 to co-operate to keep global heating to a level “well below” 2°C above the annual average for most of human history, actually kept that promise.

“Our nation has produced more of the CO2 that resides in the atmosphere today than any other country. Americans need to go on an energy diet”

But if the world’s economies continue using fossil fuels under the notorious business-as-usual scenario, then the mass of ice shed from Greenland before the close of the century could be anywhere between 8,800 billion tonnes and 35,900 billion tonnes.

“Basically, we’ve altered our planet so much that the rates of ice sheet melt this century are on pace to be greater than anything we’ve seen under natural variability of the ice sheet over the past 12,000 years.

“We’ll blow that out of the water if we don’t make severe reductions to greenhouse gas emissions,” says Jason Briner, a geologist at the University of Buffalo in New York.

“If the world goes on a massive energy diet,” he adds, “our model predicts that the Greenland Ice Sheet’s rate of mass loss this century will be only slightly higher than anything experienced in the past 12,000 years.”

If on the other hand the world follows what has always been − for climate modellers − the worst case scenario, then, he warns, “the rate of mass loss could be about four times the highest values experienced under natural climate variability over the past 12,000 years.”

‘Eye-opening’ timeline

The latest study supports a flurry of alarming observations and conclusions about Greenland’s ice sheet just in the last few months. Other teams of researchers have found that ice loss from the island is possibly irreversible, that that loss is accelerating in an Arctic region that is warming as fast as or faster than all previous “worst case” predictions, and at a rate that suggests climate scientists may even have to redefine what used to be considered Arctic conditions.

The latest study is one of a series that take the long view of climate history: it is important to separate where possible the effect of natural cycles that would anyway deliver changing conditions, from human-driven or anthropogenic change that could tip the global climate into a new and potentially catastrophic state.

“We have long timelines of temperature change, past to present to future, that show the influence of greenhouse gases on Earth’s temperature. And now, for the first time, we have a long timeline of the impacts of that temperature − in the form of Greenland Ice Sheet melt − from past to present to future. And what it shows is eye-opening,” says Professor Briner.

“Our findings are yet another wake-up call, especially for countries like the US. Americans use more energy per person than any other nation in the world.

“Our nation has produced more of the CO2 that resides in the atmosphere today than any other country. Americans need to go on an energy diet.” − Climate News Network

Greenland’s ice loss could be more this century than at any time in the history of civilization − and perhaps much more.

LONDON, 5 October, 2020 − By the end of this century Greenland’s ice loss will probably be higher than in any century during the last 12,000 years.

Even if humans take immediate drastic action to reduce greenhouse gas emissions, this new record loss will happen. And if − as seems the case − nations go on burning ever more fossil fuels and destroying ever more natural forest, then this ice loss will be four times greater than at any period in human history, according to a new study.

US, Canadian and Danish scientists report in the journal Nature that they used geological evidence and detailed computer simulations to model the past and future loss of ice from the northern hemisphere’s biggest land-borne store − Greenland bears enough ice to raise global sea levels by six metres or more − and measure possible rates of change.

On their reckoning, shortly after the end of the last Ice Age around 12,000 years ago, Greenland’s ice loss was up to 6,000 billion tonnes in the course of 100 years. That, for the entire span from then till now, stayed the record.

They calculate that the rate of loss now, based on measurements in the first 18 years of this century, could still be slightly greater, even if the 195 nations that promised in Paris in 2015 to co-operate to keep global heating to a level “well below” 2°C above the annual average for most of human history, actually kept that promise.

“Our nation has produced more of the CO2 that resides in the atmosphere today than any other country. Americans need to go on an energy diet”

But if the world’s economies continue using fossil fuels under the notorious business-as-usual scenario, then the mass of ice shed from Greenland before the close of the century could be anywhere between 8,800 billion tonnes and 35,900 billion tonnes.

“Basically, we’ve altered our planet so much that the rates of ice sheet melt this century are on pace to be greater than anything we’ve seen under natural variability of the ice sheet over the past 12,000 years.

“We’ll blow that out of the water if we don’t make severe reductions to greenhouse gas emissions,” says Jason Briner, a geologist at the University of Buffalo in New York.

“If the world goes on a massive energy diet,” he adds, “our model predicts that the Greenland Ice Sheet’s rate of mass loss this century will be only slightly higher than anything experienced in the past 12,000 years.”

If on the other hand the world follows what has always been − for climate modellers − the worst case scenario, then, he warns, “the rate of mass loss could be about four times the highest values experienced under natural climate variability over the past 12,000 years.”

‘Eye-opening’ timeline

The latest study supports a flurry of alarming observations and conclusions about Greenland’s ice sheet just in the last few months. Other teams of researchers have found that ice loss from the island is possibly irreversible, that that loss is accelerating in an Arctic region that is warming as fast as or faster than all previous “worst case” predictions, and at a rate that suggests climate scientists may even have to redefine what used to be considered Arctic conditions.

The latest study is one of a series that take the long view of climate history: it is important to separate where possible the effect of natural cycles that would anyway deliver changing conditions, from human-driven or anthropogenic change that could tip the global climate into a new and potentially catastrophic state.

“We have long timelines of temperature change, past to present to future, that show the influence of greenhouse gases on Earth’s temperature. And now, for the first time, we have a long timeline of the impacts of that temperature − in the form of Greenland Ice Sheet melt − from past to present to future. And what it shows is eye-opening,” says Professor Briner.

“Our findings are yet another wake-up call, especially for countries like the US. Americans use more energy per person than any other nation in the world.

“Our nation has produced more of the CO2 that resides in the atmosphere today than any other country. Americans need to go on an energy diet.” − Climate News Network

Abnormal heat spreads floods and wildfires globally

From the Arctic Circle to tropical Africa, abnormal heat is bringing mayhem and destruction and costing lives.

LONDON, 17 September, 2020 – Across the planet, abnormal heat is exacting a lethal toll. The west coast of the US is up in flames. Over recent months unprecedented high temperatures have been melting permafrost in Siberia, within the Arctic Circle. Fires have spread; many thousands of acres of taiga have been laid waste.

Across many parts of Africa unseasonable torrential rains are causing loss of life and crops.

Climate scientists are careful about attributing any one severe weather event to climate change until all data is gathered and a proper analysis is made.

But looking at various weather patterns around the world, fundamental changes in climate are happening – most related to big increases in temperature.

Along the western seaboard of the US people are having to cope not only with a prolonged drought but with temperatures which are way above normal.

As the ground and brush at the base of trees dries out, the ideal conditions for wildfires are set.

Over recent days more than 40,000 people in the state of Oregon have been told to evacuate their homes: dozens of people are believed to be missing in the mayhem caused by the fires.

“The debate is over.This is a climate damn emergency. This is real and it’s happening”

Kate Brown, Oregon’s governor, says that over three days recently more than 1,400 square miles of land was destroyed by fire – nearly double the amount burned over a typical year in the state.

“We have never seen this amount of uncontained fire”, said Brown.

“While our state reels from this horrific fire storm of hot weather, high winds and drought conditions, this will not be a one-time event.

“Unfortunately it is the bellwether of the future. We are feeling the acute impacts of climate change.”

Last month a group of Oregon’s leading industrialists launched a court action against Governor Brown, saying she overstepped her authority by introducing measures aimed at cutting carbon emissions in the state.

Further south in California, wildfires continue to burn. The skies of San Francisco and other cities have turned red in recent days. Smoke from the fires is causing severe air quality problems.

Gavin Newsom, California’s governor, launched an angry attack on President Trump and others who are sceptical about climate change, while visiting an area of the state destroyed by fire.

Africa inundated

“The debate is over” said Newsom. “This is a climate damn emergency. This is real and it’s happening.”

Studies say that since the early 1970s California has registered a more than fivefold increase in the annual incidence of forest fires.

A similar growing trend in abnormal heat and wildfires is being recorded in many parts of Siberia: soaring temperatures have been a big factor. In one Siberian town temperatures reached 38°C in mid-June – 18°C above the usual daytime temperature for the time of year.

Less reported on but a cause of death and hardship to some of the world’s poorest countries are floods that have been destroying homes and crops across large areas of the African continent.

In Somalia, still trying to establish itself as a functioning fully independent state in the face of terrorist attacks, nearly a million people have been affected by severe flooding in recent months.

Sudan and Ethiopia have also been subject to widespread flooding.

According to data from the US National Oceanic and Atmospheric Administration (NOAA), torrential rains and floods are affecting both east and west Africa. In Nigeria, Africa’s most populous state, thousands of homes have been destroyed and crops ruined. – Climate News Network

From the Arctic Circle to tropical Africa, abnormal heat is bringing mayhem and destruction and costing lives.

LONDON, 17 September, 2020 – Across the planet, abnormal heat is exacting a lethal toll. The west coast of the US is up in flames. Over recent months unprecedented high temperatures have been melting permafrost in Siberia, within the Arctic Circle. Fires have spread; many thousands of acres of taiga have been laid waste.

Across many parts of Africa unseasonable torrential rains are causing loss of life and crops.

Climate scientists are careful about attributing any one severe weather event to climate change until all data is gathered and a proper analysis is made.

But looking at various weather patterns around the world, fundamental changes in climate are happening – most related to big increases in temperature.

Along the western seaboard of the US people are having to cope not only with a prolonged drought but with temperatures which are way above normal.

As the ground and brush at the base of trees dries out, the ideal conditions for wildfires are set.

Over recent days more than 40,000 people in the state of Oregon have been told to evacuate their homes: dozens of people are believed to be missing in the mayhem caused by the fires.

“The debate is over.This is a climate damn emergency. This is real and it’s happening”

Kate Brown, Oregon’s governor, says that over three days recently more than 1,400 square miles of land was destroyed by fire – nearly double the amount burned over a typical year in the state.

“We have never seen this amount of uncontained fire”, said Brown.

“While our state reels from this horrific fire storm of hot weather, high winds and drought conditions, this will not be a one-time event.

“Unfortunately it is the bellwether of the future. We are feeling the acute impacts of climate change.”

Last month a group of Oregon’s leading industrialists launched a court action against Governor Brown, saying she overstepped her authority by introducing measures aimed at cutting carbon emissions in the state.

Further south in California, wildfires continue to burn. The skies of San Francisco and other cities have turned red in recent days. Smoke from the fires is causing severe air quality problems.

Gavin Newsom, California’s governor, launched an angry attack on President Trump and others who are sceptical about climate change, while visiting an area of the state destroyed by fire.

Africa inundated

“The debate is over” said Newsom. “This is a climate damn emergency. This is real and it’s happening.”

Studies say that since the early 1970s California has registered a more than fivefold increase in the annual incidence of forest fires.

A similar growing trend in abnormal heat and wildfires is being recorded in many parts of Siberia: soaring temperatures have been a big factor. In one Siberian town temperatures reached 38°C in mid-June – 18°C above the usual daytime temperature for the time of year.

Less reported on but a cause of death and hardship to some of the world’s poorest countries are floods that have been destroying homes and crops across large areas of the African continent.

In Somalia, still trying to establish itself as a functioning fully independent state in the face of terrorist attacks, nearly a million people have been affected by severe flooding in recent months.

Sudan and Ethiopia have also been subject to widespread flooding.

According to data from the US National Oceanic and Atmospheric Administration (NOAA), torrential rains and floods are affecting both east and west Africa. In Nigeria, Africa’s most populous state, thousands of homes have been destroyed and crops ruined. – Climate News Network

Melting Arctic needs new name to match reality

Change in the far north is happening so fast that soon the melting Arctic won’t be arctic any more.

LONDON, 16 September, 2020 − The word Arctic may be up for redefinition. The conditions within the melting Arctic Circle are changing so fast that what was once a frozen seascape could now be entering a new climate regime in which nothing is predictable.

Even in an unusually cold year, the sea ice may not return to the summer limits normal in the last century. For some months of autumn and even winter, rain will fall instead of snow, US scientists report in the journal Nature Climate Change.

“The rate of change is remarkable,” said Laura Landrum, of the US National Centre for Atmospheric Research, who led the study.

“It’s a period of such rapid change that observations of past weather patterns no longer show what you can expect next year. The Arctic is already entering a completely different climate than just a few decades ago.”

She and a colleague looked at four decades of satellite data and ground observations and hundreds of computer simulations to confirm that polar warming is happening at such a rate that any change year to year is no longer within the extremes of the past. Conditions that were once normally changeable are now abnormally so.

“The Arctic is already entering a completely different climate than just a few decades ago … We need to change our definition of what the Arctic is”

Climate in the northern hemisphere is moderated by temperature differences that vary with latitude: between them, a torrid equator and a frozen Arctic drive the prevailing winds and ocean currents and the mix of cloud, sunshine, rainfall, frost, windstorm, dry spells and seasonal flooding in which agriculture, industry and civilisation have evolved for the last 10,000 years.

But as carbon dioxide levels in the atmosphere soar in response to rapidly-increasing use of fossil fuels, the melting Arctic has been warming far more swiftly than the planet as a whole.

The extent of summer sea ice in each of the last 13 years has been lower than any minimum observed since 1979, when systematic observation began. Winters have been warmer, winter sea ice has been reduced, rain has been falling on snow ever earlier.

The climate scientists posed themselves the simple question: “While these changes appear extreme compared with the recent past, are they climate extremes in a statistical sense, or do they represent expected events in a new Arctic climate?”

New climate develops

The answer seems to be: yes. The researchers tested their statistical techniques on five different climate simulations. Each of these showed the sea ice retreating so dramatically that a new climate had emerged some time in the late 20th and early 21st centuries.

The finding fits a pattern of foreboding delivered by recent research. In the last two months, researchers have warned that ice loss in the Arctic regions has been so severe that the region’s most charismatic predator, the polar bear, may be gone by the century’s end.

Another group has warned that the Arctic ocean in late summer may be effectively ice-free within the next 15 years.

One group has concluded that ice loss from Greenland is now at such a rate as to be irreversible, and another has confirmed that the rate of ice melt from the northern hemisphere’s biggest reserve – enough to raise sea levels six or seven metres – last year reached new records.

And this month an international research team reported that the rate of change in the Arctic has exceeded the “worst-case” scenario proposed by climate researchers.

Unknown extremes ahead

Dr Landrum and her colleague report that − if greenhouse gas emissions continue at their present rate − some of their climate forecasts predict a mostly ice-free Arctic for between three and 10 months a year, every year, by the end of the century.

Air temperatures over the ocean in autumn and winter will become warmer before or by mid-century, and then start warming over land in the second half.

In a warmer world, more water will evaporate and fall again as rain. Over Alaska, northern Canada and northern Siberia there will be more rain rather than snow: by mid-century, perhaps an extra 20 to 60 days, and by 2100, perhaps from 60 to an extra 90 days. In some parts of the Arctic, by the century’s end, rain might fall in any month of the year.

“The Arctic is likely to experience extremes in sea ice, temperature and precipitation that are far outside anything we’ve experienced before,” Dr Landrum said. “We need to change our definition of what the Arctic is.” − Climate News Network

Change in the far north is happening so fast that soon the melting Arctic won’t be arctic any more.

LONDON, 16 September, 2020 − The word Arctic may be up for redefinition. The conditions within the melting Arctic Circle are changing so fast that what was once a frozen seascape could now be entering a new climate regime in which nothing is predictable.

Even in an unusually cold year, the sea ice may not return to the summer limits normal in the last century. For some months of autumn and even winter, rain will fall instead of snow, US scientists report in the journal Nature Climate Change.

“The rate of change is remarkable,” said Laura Landrum, of the US National Centre for Atmospheric Research, who led the study.

“It’s a period of such rapid change that observations of past weather patterns no longer show what you can expect next year. The Arctic is already entering a completely different climate than just a few decades ago.”

She and a colleague looked at four decades of satellite data and ground observations and hundreds of computer simulations to confirm that polar warming is happening at such a rate that any change year to year is no longer within the extremes of the past. Conditions that were once normally changeable are now abnormally so.

“The Arctic is already entering a completely different climate than just a few decades ago … We need to change our definition of what the Arctic is”

Climate in the northern hemisphere is moderated by temperature differences that vary with latitude: between them, a torrid equator and a frozen Arctic drive the prevailing winds and ocean currents and the mix of cloud, sunshine, rainfall, frost, windstorm, dry spells and seasonal flooding in which agriculture, industry and civilisation have evolved for the last 10,000 years.

But as carbon dioxide levels in the atmosphere soar in response to rapidly-increasing use of fossil fuels, the melting Arctic has been warming far more swiftly than the planet as a whole.

The extent of summer sea ice in each of the last 13 years has been lower than any minimum observed since 1979, when systematic observation began. Winters have been warmer, winter sea ice has been reduced, rain has been falling on snow ever earlier.

The climate scientists posed themselves the simple question: “While these changes appear extreme compared with the recent past, are they climate extremes in a statistical sense, or do they represent expected events in a new Arctic climate?”

New climate develops

The answer seems to be: yes. The researchers tested their statistical techniques on five different climate simulations. Each of these showed the sea ice retreating so dramatically that a new climate had emerged some time in the late 20th and early 21st centuries.

The finding fits a pattern of foreboding delivered by recent research. In the last two months, researchers have warned that ice loss in the Arctic regions has been so severe that the region’s most charismatic predator, the polar bear, may be gone by the century’s end.

Another group has warned that the Arctic ocean in late summer may be effectively ice-free within the next 15 years.

One group has concluded that ice loss from Greenland is now at such a rate as to be irreversible, and another has confirmed that the rate of ice melt from the northern hemisphere’s biggest reserve – enough to raise sea levels six or seven metres – last year reached new records.

And this month an international research team reported that the rate of change in the Arctic has exceeded the “worst-case” scenario proposed by climate researchers.

Unknown extremes ahead

Dr Landrum and her colleague report that − if greenhouse gas emissions continue at their present rate − some of their climate forecasts predict a mostly ice-free Arctic for between three and 10 months a year, every year, by the end of the century.

Air temperatures over the ocean in autumn and winter will become warmer before or by mid-century, and then start warming over land in the second half.

In a warmer world, more water will evaporate and fall again as rain. Over Alaska, northern Canada and northern Siberia there will be more rain rather than snow: by mid-century, perhaps an extra 20 to 60 days, and by 2100, perhaps from 60 to an extra 90 days. In some parts of the Arctic, by the century’s end, rain might fall in any month of the year.

“The Arctic is likely to experience extremes in sea ice, temperature and precipitation that are far outside anything we’ve experienced before,” Dr Landrum said. “We need to change our definition of what the Arctic is.” − Climate News Network

Arctic heating races ahead of worst case estimates

Arctic heating is happening far faster than anybody had anticipated. And the ice record suggests this has happened before.

LONDON, 2 September, 2020 – An international team of scientists brings bad news about Arctic heating: the polar ocean is warming not only faster than anybody predicted, it is getting hotter at a rate faster than even the worst case climate scenario predictions have so far foreseen.

Such dramatic rises in Arctic temperatures have been recorded before, but only during the last Ice Age. Evidence from the Greenland ice cores suggests that temperatures rose by 10°C or even 12°C, over a period of between 40 years and a century, between 120,000 years and 11,000 years ago.

“We have been clearly underestimating the rate of temperature increases in the atmosphere nearest to the sea level, which has ultimately caused sea ice to disappear faster than we had anticipated,” said Jens Hesselbjerg Christensen, a physicist at the University of Copenhagen in Denmark, one of 16 scientists who report in the journal Nature Climate Change on a new analysis of 40 years of data from the Arctic region.

They found that, on average, the Arctic has been warming at the rate of 1°C per decade for the last four decades. Around Norway’s Svalbard archipelago, temperatures rose even faster, at 1.5°C every 10 years.

“We have been clearly underestimating the rate of temperature increases in the atmosphere nearest to the sea level, which has ultimately caused sea ice to disappear faster than we had anticipated”

During the last two centuries, as atmospheric levels of carbon dioxide climbed from an average of around 285 parts per million to more than 400ppm, so the global average temperature of the planet rose: by a fraction more than 1°C.

The latest study is a reminder that temperatures in the Arctic are rising far faster than that. And the news is hardly a shock: within the past few weeks, separate teams of researchers, reporting to other journals, have warned that Greenland – the biggest single reservoir of ice in the northern hemisphere – is melting faster than ever; more alarmingly, its icecap is losing mass at a rate that suggests the loss could become irreversible.

Researchers have also confirmed that the average planetary temperature  continues to rise inexorably, that the Arctic Ocean could be free of ice in  summer as early as 2035, and that the climate scientists’ “worst case” scenarios are no longer to be regarded as a warning of what could happen: the evidence is that what is happening now already matches the climate forecaster’s worst case. The latest finding implicitly and explicitly supports this flurry of ominous observation.

“We have looked at the climate models analysed and assessed by the UN Climate Panel,” said Professor Christensen. “Only those models based on the worst case scenario, with the highest carbon dioxide emissions, come close to what our temperature measurements show over the past 40 years, from 1979 to today.” – Climate News Network

Arctic heating is happening far faster than anybody had anticipated. And the ice record suggests this has happened before.

LONDON, 2 September, 2020 – An international team of scientists brings bad news about Arctic heating: the polar ocean is warming not only faster than anybody predicted, it is getting hotter at a rate faster than even the worst case climate scenario predictions have so far foreseen.

Such dramatic rises in Arctic temperatures have been recorded before, but only during the last Ice Age. Evidence from the Greenland ice cores suggests that temperatures rose by 10°C or even 12°C, over a period of between 40 years and a century, between 120,000 years and 11,000 years ago.

“We have been clearly underestimating the rate of temperature increases in the atmosphere nearest to the sea level, which has ultimately caused sea ice to disappear faster than we had anticipated,” said Jens Hesselbjerg Christensen, a physicist at the University of Copenhagen in Denmark, one of 16 scientists who report in the journal Nature Climate Change on a new analysis of 40 years of data from the Arctic region.

They found that, on average, the Arctic has been warming at the rate of 1°C per decade for the last four decades. Around Norway’s Svalbard archipelago, temperatures rose even faster, at 1.5°C every 10 years.

“We have been clearly underestimating the rate of temperature increases in the atmosphere nearest to the sea level, which has ultimately caused sea ice to disappear faster than we had anticipated”

During the last two centuries, as atmospheric levels of carbon dioxide climbed from an average of around 285 parts per million to more than 400ppm, so the global average temperature of the planet rose: by a fraction more than 1°C.

The latest study is a reminder that temperatures in the Arctic are rising far faster than that. And the news is hardly a shock: within the past few weeks, separate teams of researchers, reporting to other journals, have warned that Greenland – the biggest single reservoir of ice in the northern hemisphere – is melting faster than ever; more alarmingly, its icecap is losing mass at a rate that suggests the loss could become irreversible.

Researchers have also confirmed that the average planetary temperature  continues to rise inexorably, that the Arctic Ocean could be free of ice in  summer as early as 2035, and that the climate scientists’ “worst case” scenarios are no longer to be regarded as a warning of what could happen: the evidence is that what is happening now already matches the climate forecaster’s worst case. The latest finding implicitly and explicitly supports this flurry of ominous observation.

“We have looked at the climate models analysed and assessed by the UN Climate Panel,” said Professor Christensen. “Only those models based on the worst case scenario, with the highest carbon dioxide emissions, come close to what our temperature measurements show over the past 40 years, from 1979 to today.” – Climate News Network

In Arctic heat Greenland’s ice loss grows faster still

Greenland’s ice loss tipped a new record last year. This ominous milestone is just the latest in a run of alarming news.

LONDON, 24 August, 2020 – Its icecap is now smaller than at any time since measurements began: Greenland’s ice loss means it lost mass in 2019 at a record rate.

By the close of the year, thanks to high summer melt and low snowfall, the northern hemisphere’s biggest reservoir of ice had shed 532 billion tonnes into the sea – raising global sea levels by around 1.5mm in a year.

The previous record loss for Greenland was in 2012. In that year, the island lost 464 billion tonnes, according to studies of satellite data published by European scientists in the journal Communications Earth and Environment.

Greenland’s ice cap has been shrinking, if unsteadily, for many years. In 2017 and 2018, the losses continued, but only at around 100bn tonnes a year.

“After a two-year breather, the mass loss increased steeply and exceeded all annual losses since 1948, and probably for more than 100 years,” said Ingo Sasgen of the Alfred Wegener Institute in Bremerhaven, Germany, who led the study.

“There are increasingly frequent, stable high-pressure areas over the ice sheet, which promote the influx of warm air from the middle latitudes. We saw a similar pattern in the previous record year, 2012.”

“The ice sheet has lost ice every year for the past 20. If everyone’s alarm bells were not already ringing, they must be now”

He and colleagues made their calculations from data delivered by two Nasa satellites, GRACE and GRACE-FO, that measure changes in the surface gravity of the planet: a way of calculating the mass of water stored as ice, or in aquifers, and observing sea level change.

The finding is the latest in a succession of polar climate alarms. It follows closely on a warning from US scientists that ice loss from Greenland may  have reached the point of no return.

And it also follows a sober calculation of the alarming rate of planetary temperature rise in response to ever-higher use of fossil fuels that trigger ever-higher measures of greenhouse gases in the atmosphere.

And that in turn followed a warning that the entire Arctic was now warming so swiftly that the Arctic sea ice might be all but gone in the summer of 2035.

And that was only days after another research team, looking at the big picture of climate change, warned that the scenario climate forecasters liked to use as an example of their “worst case” was now a simple description of what was already happening.

“It is devastating that 2019 was another record year of ice loss. In 2012, it had been about 150 years since the ice sheet had experienced similar melt extent, and then a further 600-plus years back to find another similar event,” said Twila Moon, of the University of Colorado at Boulder, who was not involved in the research.

Damage off the scale

“We have now had record-breaking ice loss twice in less than 10 years, and the ice sheet has lost ice every year for the past 20. If everyone’s alarm bells were not already ringing, they must be now.”

The implications of continued loss of Greenland ice have been explored repeatedly: the run-off of fresh water from the ice cap to the sea is now so great that the North Atlantic is now “fresher” than at any time in the last 100 years.

And this change in water temperature and chemistry could – on the evidence of the distant past – possibly slow or switch off the circulation of the North Atlantic current, which for most of the history of human civilisation has kept the United Kingdom and north-western Europe from five to 10°C warmer than similar latitudes elsewhere.

“This tipping point in the climate system is one of the potential climate disasters facing us,” said Stuart Cunningham of the Scottish Association for Marine Science, commenting on the study.

“To transform the way we power, finance and run the world in the way we know we should is proving entirely beyond us,” said Chris Rapley, now a climate scientist at University College London, but once director of the British Antarctic Survey.

“Torpor, incompetence and indifference at the top may kill people in a health crisis, and torpedo the careers of young students in an education crisis; but the damage they are generating in the pipeline from climate change is on another scale.” – Climate News Network

Greenland’s ice loss tipped a new record last year. This ominous milestone is just the latest in a run of alarming news.

LONDON, 24 August, 2020 – Its icecap is now smaller than at any time since measurements began: Greenland’s ice loss means it lost mass in 2019 at a record rate.

By the close of the year, thanks to high summer melt and low snowfall, the northern hemisphere’s biggest reservoir of ice had shed 532 billion tonnes into the sea – raising global sea levels by around 1.5mm in a year.

The previous record loss for Greenland was in 2012. In that year, the island lost 464 billion tonnes, according to studies of satellite data published by European scientists in the journal Communications Earth and Environment.

Greenland’s ice cap has been shrinking, if unsteadily, for many years. In 2017 and 2018, the losses continued, but only at around 100bn tonnes a year.

“After a two-year breather, the mass loss increased steeply and exceeded all annual losses since 1948, and probably for more than 100 years,” said Ingo Sasgen of the Alfred Wegener Institute in Bremerhaven, Germany, who led the study.

“There are increasingly frequent, stable high-pressure areas over the ice sheet, which promote the influx of warm air from the middle latitudes. We saw a similar pattern in the previous record year, 2012.”

“The ice sheet has lost ice every year for the past 20. If everyone’s alarm bells were not already ringing, they must be now”

He and colleagues made their calculations from data delivered by two Nasa satellites, GRACE and GRACE-FO, that measure changes in the surface gravity of the planet: a way of calculating the mass of water stored as ice, or in aquifers, and observing sea level change.

The finding is the latest in a succession of polar climate alarms. It follows closely on a warning from US scientists that ice loss from Greenland may  have reached the point of no return.

And it also follows a sober calculation of the alarming rate of planetary temperature rise in response to ever-higher use of fossil fuels that trigger ever-higher measures of greenhouse gases in the atmosphere.

And that in turn followed a warning that the entire Arctic was now warming so swiftly that the Arctic sea ice might be all but gone in the summer of 2035.

And that was only days after another research team, looking at the big picture of climate change, warned that the scenario climate forecasters liked to use as an example of their “worst case” was now a simple description of what was already happening.

“It is devastating that 2019 was another record year of ice loss. In 2012, it had been about 150 years since the ice sheet had experienced similar melt extent, and then a further 600-plus years back to find another similar event,” said Twila Moon, of the University of Colorado at Boulder, who was not involved in the research.

Damage off the scale

“We have now had record-breaking ice loss twice in less than 10 years, and the ice sheet has lost ice every year for the past 20. If everyone’s alarm bells were not already ringing, they must be now.”

The implications of continued loss of Greenland ice have been explored repeatedly: the run-off of fresh water from the ice cap to the sea is now so great that the North Atlantic is now “fresher” than at any time in the last 100 years.

And this change in water temperature and chemistry could – on the evidence of the distant past – possibly slow or switch off the circulation of the North Atlantic current, which for most of the history of human civilisation has kept the United Kingdom and north-western Europe from five to 10°C warmer than similar latitudes elsewhere.

“This tipping point in the climate system is one of the potential climate disasters facing us,” said Stuart Cunningham of the Scottish Association for Marine Science, commenting on the study.

“To transform the way we power, finance and run the world in the way we know we should is proving entirely beyond us,” said Chris Rapley, now a climate scientist at University College London, but once director of the British Antarctic Survey.

“Torpor, incompetence and indifference at the top may kill people in a health crisis, and torpedo the careers of young students in an education crisis; but the damage they are generating in the pipeline from climate change is on another scale.” – Climate News Network

Greenland is losing more ice than it gains annually

The ice lost to the sea annually off Greenland is now more than the snow falling on the island. This is a tipping point.

LONDON, 18 August, 2020 – The loss of ice from Greenland may have reached the point of no return. The island’s glaciers have dwindled and retreated so much that annual snowfall can no longer replace the lost ice.

New studies confirm that between 1980 and the year 2000, the island – the biggest single store of ice in the northern hemisphere – lost on average 450 billion tonnes of ice each year from its glaciers. This is about what falls as snow and stays on the island’s surface each year.

And then 20 years ago the rate of melt – already speeding up – accelerated again. The glaciers are now spilling more than 500 billion tonnes of ice into the seas. But snowfall has not increased.

And US scientists warn, in the normally guarded language of science, of a “switch to a new dynamic state of sustained mass loss that would persist even under a decline in surface melt.”

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss”

The scientists base their new conclusions on a careful re-examination of 40 years of satellite observations to check the rates of snowfall and ice loss. “What we’ve found is that the ice that’s discharging into the ocean is far surpassing the snow that’s accumulating on the surface of the ice sheet,” said Michalea King of Ohio State University, who led the research. .

The news, in the journal Nature Communications Earth and Environment, is alarming but hardly surprising. In December researchers warned that – even to begin to arrest the melting of a store of ice big enough to raise global sea levels by up to seven metres the world would have to take immediate and drastic steps to halt global heating.

Researchers have found that surface melting is at a rate that has begun to make the glaciers more unstable. They have confirmed that the rate of melt is accelerating so swiftly that the bedrock beneath the weight of ice has begun to rise, while a range of other climate change triggers has begun to darken the ice cover in ways that can only increase the absorption of heat and step up the rate of melt.

The latest evidence is that the world has passed a tipping point of sorts: once such things happen, there is no way back.

Glaciers gather speed

All icecaps melt in summer, and all icecaps are drained by glaciers, rivers of ice that make slow progress to the sea. In a stable climate, annual precipitation and annual glacier calving remain more or less in balance, and the icecap functions as its own refrigerant. The whiteness of the ice reflects sunlight back into space and insulates itself against significant loss.

But as the air and oceans warm in response to ever higher levels of greenhouse gases pumped into the atmosphere as nations continue to burn ever more coal, oil and gas, the rates of melt became more dramatic and the glaciers began to flow ever faster: one of them was clocked at 45 metres a day.

The message of the latest research is that, even if somehow humans could immediately halt climate change, the ice likely to be lost as the glaciers reach the sea would still be greater than the accumulation of ice on the surface each winter.

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss,” said Ian Howat, a co-author at Ohio State University. “Even if the climate were to stay the same or get a little colder, the ice sheet would still be losing mass.” – Climate News Network

The ice lost to the sea annually off Greenland is now more than the snow falling on the island. This is a tipping point.

LONDON, 18 August, 2020 – The loss of ice from Greenland may have reached the point of no return. The island’s glaciers have dwindled and retreated so much that annual snowfall can no longer replace the lost ice.

New studies confirm that between 1980 and the year 2000, the island – the biggest single store of ice in the northern hemisphere – lost on average 450 billion tonnes of ice each year from its glaciers. This is about what falls as snow and stays on the island’s surface each year.

And then 20 years ago the rate of melt – already speeding up – accelerated again. The glaciers are now spilling more than 500 billion tonnes of ice into the seas. But snowfall has not increased.

And US scientists warn, in the normally guarded language of science, of a “switch to a new dynamic state of sustained mass loss that would persist even under a decline in surface melt.”

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss”

The scientists base their new conclusions on a careful re-examination of 40 years of satellite observations to check the rates of snowfall and ice loss. “What we’ve found is that the ice that’s discharging into the ocean is far surpassing the snow that’s accumulating on the surface of the ice sheet,” said Michalea King of Ohio State University, who led the research. .

The news, in the journal Nature Communications Earth and Environment, is alarming but hardly surprising. In December researchers warned that – even to begin to arrest the melting of a store of ice big enough to raise global sea levels by up to seven metres the world would have to take immediate and drastic steps to halt global heating.

Researchers have found that surface melting is at a rate that has begun to make the glaciers more unstable. They have confirmed that the rate of melt is accelerating so swiftly that the bedrock beneath the weight of ice has begun to rise, while a range of other climate change triggers has begun to darken the ice cover in ways that can only increase the absorption of heat and step up the rate of melt.

The latest evidence is that the world has passed a tipping point of sorts: once such things happen, there is no way back.

Glaciers gather speed

All icecaps melt in summer, and all icecaps are drained by glaciers, rivers of ice that make slow progress to the sea. In a stable climate, annual precipitation and annual glacier calving remain more or less in balance, and the icecap functions as its own refrigerant. The whiteness of the ice reflects sunlight back into space and insulates itself against significant loss.

But as the air and oceans warm in response to ever higher levels of greenhouse gases pumped into the atmosphere as nations continue to burn ever more coal, oil and gas, the rates of melt became more dramatic and the glaciers began to flow ever faster: one of them was clocked at 45 metres a day.

The message of the latest research is that, even if somehow humans could immediately halt climate change, the ice likely to be lost as the glaciers reach the sea would still be greater than the accumulation of ice on the surface each winter.

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss,” said Ian Howat, a co-author at Ohio State University. “Even if the climate were to stay the same or get a little colder, the ice sheet would still be losing mass.” – Climate News Network

End of Arctic sea ice by 2035 possible, study finds

How soon will the northern polar ocean be ice-free? New research expects the end of Arctic sea ice by 2035.

LONDON, 11 August, 2020 − The temperature of the Arctic matters to the entire world: it helps to keep the global climate fairly cool. Scientists now say that by 2035 there could be an end to Arctic sea ice.

The northern polar ocean’s sea ice is a crucial element in the Earth system: because it is highly reflective, it sends solar radiation back out into space. Once it’s melted, there’s no longer any protection for the darker water and rock beneath, and nothing to prevent them absorbing the incoming heat.

High temperatures in the Arctic during the last interglacial – the warm period around 127,000 years ago – have puzzled scientists for decades.

Now the UK Met Office’s Hadley Centre climate model has enabled an international research team to compare Arctic sea ice conditions during the last interglacial with the present day. Their findings are important for improving predictions of future sea ice change.

What is striking about the latest research is the date it suggests for a possible total melt − 2035. Many studies have thought a mid-century crisis likely, with another even carefully specifying 2044 as the year to watch. So a breathing space of only 15 years may surprise some experts.

“The prospect of loss of sea ice by 2035 should really be focussing all our minds on achieving a low-carbon world as soon as humanly feasible”

During spring and early summer shallow pools of water form on the surface of the Arctic sea ice. These “melt ponds” help to determine how much sunlight is absorbed by the ice and how much is reflected back into space. The new Hadley Centre model is the UK’s most advanced physical representation of the Earth’s climate and a critical tool for climate research, and it incorporates sea ice and melt ponds.

The researchers report their findings in the journal Nature Climate Change. Using the model to look at Arctic sea ice during the last interglacial, they concluded that the impact of intense springtime sunshine created many melt ponds, which played a crucial role in sea ice melt. A simulation of the future using the same model indicates that the Arctic may become sea ice-free by 2035.

The joint lead author of the team is Dr Maria Vittoria Guarino, an earth system modeller at the British Antarctic Survey (BAS) in Cambridge. She says: “High temperatures in the Arctic have puzzled scientists for decades. Unravelling this mystery was technically and scientifically challenging. For the first time, we can begin to see how the Arctic became sea ice-free during the last interglacial.

“The advances made in climate modelling mean that we can create a more accurate simulation of the Earth’s past climate which, in turn, gives us greater confidence in model predictions for the future.”

Dr Louise Sime, the group head of the palaeoclimate group and joint lead author at BAS, says: “We know the Arctic is undergoing significant changes as our planet warms. By understanding what happened during Earth’s last warm period we are in a better position to understand what will happen in the future.

Melt ponds crucial

“The prospect of loss of sea ice by 2035 should really be focussing all our minds on achieving a low-carbon world as soon as humanly feasible.”

Dr David Schroeder from the University of Reading, UK, who co-led the implementation of the melt pond scheme in the climate model, says: “This shows just how important sea ice processes like melt ponds are in the Arctic, and why it is crucial that they are incorporated into climate models.”

The extent of the areas sea ice covers varies between summer and winter. If more solar energy is absorbed at the surface, and temperatures rise further, a cycle of warming and melting occurs during summer months.

When the ice forms, the ocean water beneath becomes saltier and denser than the surrounding ocean. Saltier water sinks and moves along the ocean bottom towards the equator, while warm water from mid-depths to the surface travels from the equator towards the poles.

Scientists refer to this process as the ocean’s global “conveyor-belt”. Changes to the volume of sea ice can disrupt normal ocean circulation, with consequences for global climate. − Climate News Network

How soon will the northern polar ocean be ice-free? New research expects the end of Arctic sea ice by 2035.

LONDON, 11 August, 2020 − The temperature of the Arctic matters to the entire world: it helps to keep the global climate fairly cool. Scientists now say that by 2035 there could be an end to Arctic sea ice.

The northern polar ocean’s sea ice is a crucial element in the Earth system: because it is highly reflective, it sends solar radiation back out into space. Once it’s melted, there’s no longer any protection for the darker water and rock beneath, and nothing to prevent them absorbing the incoming heat.

High temperatures in the Arctic during the last interglacial – the warm period around 127,000 years ago – have puzzled scientists for decades.

Now the UK Met Office’s Hadley Centre climate model has enabled an international research team to compare Arctic sea ice conditions during the last interglacial with the present day. Their findings are important for improving predictions of future sea ice change.

What is striking about the latest research is the date it suggests for a possible total melt − 2035. Many studies have thought a mid-century crisis likely, with another even carefully specifying 2044 as the year to watch. So a breathing space of only 15 years may surprise some experts.

“The prospect of loss of sea ice by 2035 should really be focussing all our minds on achieving a low-carbon world as soon as humanly feasible”

During spring and early summer shallow pools of water form on the surface of the Arctic sea ice. These “melt ponds” help to determine how much sunlight is absorbed by the ice and how much is reflected back into space. The new Hadley Centre model is the UK’s most advanced physical representation of the Earth’s climate and a critical tool for climate research, and it incorporates sea ice and melt ponds.

The researchers report their findings in the journal Nature Climate Change. Using the model to look at Arctic sea ice during the last interglacial, they concluded that the impact of intense springtime sunshine created many melt ponds, which played a crucial role in sea ice melt. A simulation of the future using the same model indicates that the Arctic may become sea ice-free by 2035.

The joint lead author of the team is Dr Maria Vittoria Guarino, an earth system modeller at the British Antarctic Survey (BAS) in Cambridge. She says: “High temperatures in the Arctic have puzzled scientists for decades. Unravelling this mystery was technically and scientifically challenging. For the first time, we can begin to see how the Arctic became sea ice-free during the last interglacial.

“The advances made in climate modelling mean that we can create a more accurate simulation of the Earth’s past climate which, in turn, gives us greater confidence in model predictions for the future.”

Dr Louise Sime, the group head of the palaeoclimate group and joint lead author at BAS, says: “We know the Arctic is undergoing significant changes as our planet warms. By understanding what happened during Earth’s last warm period we are in a better position to understand what will happen in the future.

Melt ponds crucial

“The prospect of loss of sea ice by 2035 should really be focussing all our minds on achieving a low-carbon world as soon as humanly feasible.”

Dr David Schroeder from the University of Reading, UK, who co-led the implementation of the melt pond scheme in the climate model, says: “This shows just how important sea ice processes like melt ponds are in the Arctic, and why it is crucial that they are incorporated into climate models.”

The extent of the areas sea ice covers varies between summer and winter. If more solar energy is absorbed at the surface, and temperatures rise further, a cycle of warming and melting occurs during summer months.

When the ice forms, the ocean water beneath becomes saltier and denser than the surrounding ocean. Saltier water sinks and moves along the ocean bottom towards the equator, while warm water from mid-depths to the surface travels from the equator towards the poles.

Scientists refer to this process as the ocean’s global “conveyor-belt”. Changes to the volume of sea ice can disrupt normal ocean circulation, with consequences for global climate. − Climate News Network

Food shortage may finish polar bears by 2100

How long polar bears can survive depends on how long they can last without food. And that may be: not long enough.

LONDON, 24 July, 2020 − As the Arctic sea ice dwindles, so will hope for the region’s most dramatic predator, its polar bears. A creature fashioned by evolution to fast a whole summer and gorge through the autumn and winter may not last, as the ice melts ever earlier and forms ever later.

That is because Ursus maritimus can find the food for the next generation of its cubs only by prowling the firm sea ice for a high-calorie diet of seal flesh and blubber.

And now a team of Canadian and US scientists has begun to establish the unknown of polar bear survival: how many days the creature can survive without food and still nourish its young and sustain life.

They call this the “fasting impact threshold” and the answer, they report in the journal Nature Climate Change, is not encouraging.

“Polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist”

If warming continues at the present rate, then by the century’s end most of the sub-populations of this charismatic animal will not survive.

“The challenge is that the Arctic ice will keep disappearing as the world continues to warm,” said Péter Molnár, of the University of Toronto Scarborough, who led the research.

“This means polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist as healthy populations.”

The researchers had to start with one big uncertainty: how much stored energy the bear has when the fasting season begins. Because the shelf ice has been thinning and shrinking for more than 40 years, hunting seasons have become shorter and bears now spend longer and longer on land.

Natural variability

That raised a second factor: some parts of the Arctic lose ice earlier than others. The third unknown is the health of the 19 sub-populations of Ursus maritimus, spread over four distinct eco-regions within the Arctic Circle, and how these separate populations would consider a “good” hunting season and a happy period of fasting.

In the southern Beaufort Sea, fewer than 127 ice-free days could be considered “good”, but even this seemingly assured number was based on only five years of systematic demographic data.

And then the researchers had to calculate the demands placed on individual bears: an adult male might be able to last 200 days; a solitary adult female up to 255 days. But a mother bear might begin to lose what it takes to get cubs through to maturity as early as 117 days, and certainly after 228 days.

But however incomplete, the scientists had data for about 80% of the polar bear populations, collected between 1979 and 2016, and report that what they politely call “recruitment and survival impact thresholds” may have already been exceeded in some populations.

Too hopeful?

That is, there are increasing numbers of bears in the Arctic no longer sure of having cubs or keeping them alive. That includes the polar bears of Hudson Bay and the Davis Strait in northern Canada: perhaps the most photographed bears in the world.

And if the world goes on warming, only a few creatures in the very high Arctic will see the next century.

“While our projections for the future of polar bears seem dire, the unfortunate thing is they might even be too optimistic. For example, we assumed that polar bears will use their available body energy in optimal ways when fasting. If that isn’t the case, the reality could be worse than our projections,” Dr Molnár said.

“What we do know is that becoming fat before a fasting season will be more difficult for polar bears as on-ice hunting seasons become shorter, so it’s likely that fasting impact thresholds will be crossed in the early years of our projected range.” − Climate News Network

How long polar bears can survive depends on how long they can last without food. And that may be: not long enough.

LONDON, 24 July, 2020 − As the Arctic sea ice dwindles, so will hope for the region’s most dramatic predator, its polar bears. A creature fashioned by evolution to fast a whole summer and gorge through the autumn and winter may not last, as the ice melts ever earlier and forms ever later.

That is because Ursus maritimus can find the food for the next generation of its cubs only by prowling the firm sea ice for a high-calorie diet of seal flesh and blubber.

And now a team of Canadian and US scientists has begun to establish the unknown of polar bear survival: how many days the creature can survive without food and still nourish its young and sustain life.

They call this the “fasting impact threshold” and the answer, they report in the journal Nature Climate Change, is not encouraging.

“Polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist”

If warming continues at the present rate, then by the century’s end most of the sub-populations of this charismatic animal will not survive.

“The challenge is that the Arctic ice will keep disappearing as the world continues to warm,” said Péter Molnár, of the University of Toronto Scarborough, who led the research.

“This means polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist as healthy populations.”

The researchers had to start with one big uncertainty: how much stored energy the bear has when the fasting season begins. Because the shelf ice has been thinning and shrinking for more than 40 years, hunting seasons have become shorter and bears now spend longer and longer on land.

Natural variability

That raised a second factor: some parts of the Arctic lose ice earlier than others. The third unknown is the health of the 19 sub-populations of Ursus maritimus, spread over four distinct eco-regions within the Arctic Circle, and how these separate populations would consider a “good” hunting season and a happy period of fasting.

In the southern Beaufort Sea, fewer than 127 ice-free days could be considered “good”, but even this seemingly assured number was based on only five years of systematic demographic data.

And then the researchers had to calculate the demands placed on individual bears: an adult male might be able to last 200 days; a solitary adult female up to 255 days. But a mother bear might begin to lose what it takes to get cubs through to maturity as early as 117 days, and certainly after 228 days.

But however incomplete, the scientists had data for about 80% of the polar bear populations, collected between 1979 and 2016, and report that what they politely call “recruitment and survival impact thresholds” may have already been exceeded in some populations.

Too hopeful?

That is, there are increasing numbers of bears in the Arctic no longer sure of having cubs or keeping them alive. That includes the polar bears of Hudson Bay and the Davis Strait in northern Canada: perhaps the most photographed bears in the world.

And if the world goes on warming, only a few creatures in the very high Arctic will see the next century.

“While our projections for the future of polar bears seem dire, the unfortunate thing is they might even be too optimistic. For example, we assumed that polar bears will use their available body energy in optimal ways when fasting. If that isn’t the case, the reality could be worse than our projections,” Dr Molnár said.

“What we do know is that becoming fat before a fasting season will be more difficult for polar bears as on-ice hunting seasons become shorter, so it’s likely that fasting impact thresholds will be crossed in the early years of our projected range.” − Climate News Network