Tag Archives: Arctic

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

Human climate change causes Arctic’s record heat

The coldest place in the Arctic has experienced record heat. Climate change has made this 600 times more probable.

LONDON, 23 July, 2020 – An international team of scientists has pinned the strange weather and record heat in the Siberian Arctic firmly on human-induced climate change.

On average, from January to June, temperatures in the region have been 5°C hotter because the world’s cities have continued to consume ever-increasing levels of fossil fuels.

The researchers report that, without human help, such freak conditions could happen only once every 80,000 years or so. But a steady increase in greenhouse gas levels in the atmosphere for the last century or more has increased the chances of record temperatures – one Arctic Circle settlement, Verkhoyansk, normally one of the coldest places on Earth, recorded 38°C on 20 June – by a factor of 600.

“The findings of this rapid research – that climate change increased the chances of prolonged heat in Siberia by at least 600 times – are truly staggering,” said Andrew Ciavarella, of the UK Met Office, who led the study.

“This research is further evidence of the extreme temperatures we can expect to see more frequently around the world in a warming global climate. Importantly, an increasing frequency of these extreme heat events can be moderated by reducing greenhouse gas emissions.”

Confidence grows

That climate change has come to the Arctic is not news: what is significant about the research by British, French, Swiss, Dutch, German and Russian meteorologists is the readiness to put the blame fairly on climate change, even for a freak event.

It has always been a given in the science that the mix of air pressure and temperatures around the world delivers a random pattern of change marked by extremes, and for decades scientists backed away from blaming any single flood, windstorm or heat wave as evidence of climate change. That has, in the last few years, changed.

Research teams have successively warned that climate change driven by human action had contributed to California’s most recent disastrous drought; that both calamitous floods and catastrophic bushfires in Australia were made more probable and more intense by rising greenhouse gas emissions; and that the signature of climate change driven by fossil fuel combustion was now detectable in daily weather changes almost anywhere around the globe.

But the signature of climate change in the Siberian Arctic has been pronounced, and the latest attribution study is confirmation of a new confidence in the data.

“The findings of this rapid research – that climate change increased the chances of prolonged heat in Siberia by at least 600 times – are truly staggering”

In June, forest fires in Siberia consumed 1.15 million hectares and released about 56 million tonnes of carbon dioxide: this is more than the annual emissions from Switzerland or Norway.

The rising temperatures in the region have been grounds for extra alarm: permafrost in the Arctic Circle is a store of carbon that is increasingly being released as the ground thaws, to make Arctic warming even worse.

But the hazards of permafrost thaw are also direct: soils become more vulnerable to slip and slump, and there is already measurable damage to the infrastructure once supported by sediments and topsoils that used to be frozen solid all year round.

The region recorded one of the world’s worst oil spills in May, when an oil tank collapsed. The unseasonal and improbable heat has been coupled to an explosion of silk moths, bringing further caterpillar damage to conifer forests.

Even now such temperatures remain unlikely: the human component of climate change has simply reduced the frequency of such sustained temperatures to perhaps once every 135 years.

Little time left

But without rapid and drastic cuts worldwide in greenhouse gas emissions, towns like Verkhoyansk – which also shares the record for the coldest temperature in the northern hemisphere – could become a lot warmer, a lot more often before the century’s end.

“These results show that we are starting to experience extreme events which have almost no chance of happening without a human footprint on the climate system,” said Sonia Seneviratne, of the Swiss Federal Institute of Technology, known as ETH Zurich.

“We have little time left to stabilise global warming at levels at which climate change would lie within the bounds of the Paris Agreement.

“For a stabilisation at 1.5°C of global warming, which would still imply risks of such extreme heat events, we need to reduce our CO2 emissions by at least half until 2030.” – Climate News Network

The coldest place in the Arctic has experienced record heat. Climate change has made this 600 times more probable.

LONDON, 23 July, 2020 – An international team of scientists has pinned the strange weather and record heat in the Siberian Arctic firmly on human-induced climate change.

On average, from January to June, temperatures in the region have been 5°C hotter because the world’s cities have continued to consume ever-increasing levels of fossil fuels.

The researchers report that, without human help, such freak conditions could happen only once every 80,000 years or so. But a steady increase in greenhouse gas levels in the atmosphere for the last century or more has increased the chances of record temperatures – one Arctic Circle settlement, Verkhoyansk, normally one of the coldest places on Earth, recorded 38°C on 20 June – by a factor of 600.

“The findings of this rapid research – that climate change increased the chances of prolonged heat in Siberia by at least 600 times – are truly staggering,” said Andrew Ciavarella, of the UK Met Office, who led the study.

“This research is further evidence of the extreme temperatures we can expect to see more frequently around the world in a warming global climate. Importantly, an increasing frequency of these extreme heat events can be moderated by reducing greenhouse gas emissions.”

Confidence grows

That climate change has come to the Arctic is not news: what is significant about the research by British, French, Swiss, Dutch, German and Russian meteorologists is the readiness to put the blame fairly on climate change, even for a freak event.

It has always been a given in the science that the mix of air pressure and temperatures around the world delivers a random pattern of change marked by extremes, and for decades scientists backed away from blaming any single flood, windstorm or heat wave as evidence of climate change. That has, in the last few years, changed.

Research teams have successively warned that climate change driven by human action had contributed to California’s most recent disastrous drought; that both calamitous floods and catastrophic bushfires in Australia were made more probable and more intense by rising greenhouse gas emissions; and that the signature of climate change driven by fossil fuel combustion was now detectable in daily weather changes almost anywhere around the globe.

But the signature of climate change in the Siberian Arctic has been pronounced, and the latest attribution study is confirmation of a new confidence in the data.

“The findings of this rapid research – that climate change increased the chances of prolonged heat in Siberia by at least 600 times – are truly staggering”

In June, forest fires in Siberia consumed 1.15 million hectares and released about 56 million tonnes of carbon dioxide: this is more than the annual emissions from Switzerland or Norway.

The rising temperatures in the region have been grounds for extra alarm: permafrost in the Arctic Circle is a store of carbon that is increasingly being released as the ground thaws, to make Arctic warming even worse.

But the hazards of permafrost thaw are also direct: soils become more vulnerable to slip and slump, and there is already measurable damage to the infrastructure once supported by sediments and topsoils that used to be frozen solid all year round.

The region recorded one of the world’s worst oil spills in May, when an oil tank collapsed. The unseasonal and improbable heat has been coupled to an explosion of silk moths, bringing further caterpillar damage to conifer forests.

Even now such temperatures remain unlikely: the human component of climate change has simply reduced the frequency of such sustained temperatures to perhaps once every 135 years.

Little time left

But without rapid and drastic cuts worldwide in greenhouse gas emissions, towns like Verkhoyansk – which also shares the record for the coldest temperature in the northern hemisphere – could become a lot warmer, a lot more often before the century’s end.

“These results show that we are starting to experience extreme events which have almost no chance of happening without a human footprint on the climate system,” said Sonia Seneviratne, of the Swiss Federal Institute of Technology, known as ETH Zurich.

“We have little time left to stabilise global warming at levels at which climate change would lie within the bounds of the Paris Agreement.

“For a stabilisation at 1.5°C of global warming, which would still imply risks of such extreme heat events, we need to reduce our CO2 emissions by at least half until 2030.” – Climate News Network

Arctic Ocean is set for more turbulent future

The Arctic Ocean is about to become more violent, with higher storm waves and higher frequency, across a wide region.

LONDON, 20 July, 2020 − The Arctic Ocean is changing, and changing fast. By the century’s end, the maximum height of storm waves in the polar seas could have risen by twice or even three times the present height.

According to new research, wave heights could increase by two metres and coastal floods could become four times, or even 10 times, as frequent.

And a separate study has found that even the character of the water in the ocean is changing: warm salty water from the Atlantic is weakening the ice cover at an accelerating rate, but providing more nutrients for Arctic life, while extra river water from the Pacific has made the American-Asian part of the Arctic Ocean less likely to mix, and less biologically productive.

The Arctic is warming at twice the rate of the planet as a whole: the ice cover has been thinning and retreating for decades. And temperatures keep on rising.

One Siberian town recorded a temperature of 38°C in June, and the region has been hit by devastating forest fires.

“In many respects, the Arctic Ocean now looks like a new ocean”

And as the oceans warm, winds become more powerful and the ocean waves respond, with prospects of ever-greater hazard for shipping and coastal settlements.

Extreme wave events that once occurred in the Arctic at average intervals of once every 20 years could by the end of the century happen every two to five years, according a study in the Journal of Geophysical Research: Oceans.

“It increases the risk of flooding and erosion. It increases drastically almost everywhere”, said Mercè Casas-Prat, a researcher with Environment and Climate Change Canada. “This can have a direct impact on communities that live close to the shoreline.”

She and a colleague used computer simulations and a range of climate predictions to work out what will happen to those ocean surfaces not covered by ice as the seas warm in response to greenhouse gas emissions from fossil fuel combustion.

They found that almost everywhere in the Arctic would experience greater wave height. The hardest-hit would be the Greenland Sea, bounded by the largest body of ice in the northern hemisphere, and the Svalbard Archipelago.

More salty water

Maximum annual wave heights could increase by as much as six metres.
“At the end of the century, the maximum will on average come later in the year and also be more extreme,” Dr Casas-Prat said.

The Arctic Ocean covers only about 3% of the planet’s surface, but it is vulnerable to change in ocean regions much nearer the Equator. US and Scandinavian scientists report in the journal Frontiers in Marine Science that they looked at 37 years of direct observation and measurement to find that not only are Arctic waters changing: they are changing in different ways.

Flows of increasingly warm salty water from the Atlantic have begun to mix at depth, weaken sea ice and bring deeper, nutrient-rich water to the surface. At the other entrance to the partly landlocked expanse of water, an increasing flow from rivers has begun to make the separation of surface and deep layers even more pronounced.

This limits the movement of nutrients to the surface, protentially making that part of the sea less biologically rich. Many marine creatures from low latitudes are moving north, in some cases replacing local species. The changes could affect fisheries, tourism, navigation and of course the people who live in the Arctic.

“In many respects, the Arctic Ocean now looks like a new ocean,” said Igor Polyakov, an oceanographer at the University of Fairbanks, Alaska, who led the research. − Climate News Network

The Arctic Ocean is about to become more violent, with higher storm waves and higher frequency, across a wide region.

LONDON, 20 July, 2020 − The Arctic Ocean is changing, and changing fast. By the century’s end, the maximum height of storm waves in the polar seas could have risen by twice or even three times the present height.

According to new research, wave heights could increase by two metres and coastal floods could become four times, or even 10 times, as frequent.

And a separate study has found that even the character of the water in the ocean is changing: warm salty water from the Atlantic is weakening the ice cover at an accelerating rate, but providing more nutrients for Arctic life, while extra river water from the Pacific has made the American-Asian part of the Arctic Ocean less likely to mix, and less biologically productive.

The Arctic is warming at twice the rate of the planet as a whole: the ice cover has been thinning and retreating for decades. And temperatures keep on rising.

One Siberian town recorded a temperature of 38°C in June, and the region has been hit by devastating forest fires.

“In many respects, the Arctic Ocean now looks like a new ocean”

And as the oceans warm, winds become more powerful and the ocean waves respond, with prospects of ever-greater hazard for shipping and coastal settlements.

Extreme wave events that once occurred in the Arctic at average intervals of once every 20 years could by the end of the century happen every two to five years, according a study in the Journal of Geophysical Research: Oceans.

“It increases the risk of flooding and erosion. It increases drastically almost everywhere”, said Mercè Casas-Prat, a researcher with Environment and Climate Change Canada. “This can have a direct impact on communities that live close to the shoreline.”

She and a colleague used computer simulations and a range of climate predictions to work out what will happen to those ocean surfaces not covered by ice as the seas warm in response to greenhouse gas emissions from fossil fuel combustion.

They found that almost everywhere in the Arctic would experience greater wave height. The hardest-hit would be the Greenland Sea, bounded by the largest body of ice in the northern hemisphere, and the Svalbard Archipelago.

More salty water

Maximum annual wave heights could increase by as much as six metres.
“At the end of the century, the maximum will on average come later in the year and also be more extreme,” Dr Casas-Prat said.

The Arctic Ocean covers only about 3% of the planet’s surface, but it is vulnerable to change in ocean regions much nearer the Equator. US and Scandinavian scientists report in the journal Frontiers in Marine Science that they looked at 37 years of direct observation and measurement to find that not only are Arctic waters changing: they are changing in different ways.

Flows of increasingly warm salty water from the Atlantic have begun to mix at depth, weaken sea ice and bring deeper, nutrient-rich water to the surface. At the other entrance to the partly landlocked expanse of water, an increasing flow from rivers has begun to make the separation of surface and deep layers even more pronounced.

This limits the movement of nutrients to the surface, protentially making that part of the sea less biologically rich. Many marine creatures from low latitudes are moving north, in some cases replacing local species. The changes could affect fisheries, tourism, navigation and of course the people who live in the Arctic.

“In many respects, the Arctic Ocean now looks like a new ocean,” said Igor Polyakov, an oceanographer at the University of Fairbanks, Alaska, who led the research. − Climate News Network

Siberia dries out as forests burn and climate heats

A huge swathe of Arctic Russia is changing rapidly as oil leaks, the climate warms and Siberia dries out.

LONDON, 5 June, 2020 – Residents of the small Arctic town of Khatanga have never experienced anything like it: their home is changing at a gallop as Siberia dries out.

Khatanga – population around 3,500 – is well north of the Arctic Circle, with usual daytime temperatures at this time of year hovering round a chilly 0°C. On 22 May the temperature in the town reached 25°C – more than double the record to date.

Global warming is causing profound change across the Arctic, a region which acts like a giant air conditioning system regulating the Earth’s climate.

Temperatures are rising far faster than elsewhere: sea ice cover is rapidly disappearing, valuable fish stocks are moving ever further north in search of colder waters, land around the Arctic perimeter is drying out – particularly across the vast expanse of Siberia.

Permafrost is melting. This week a giant oil tank collapsed and ruptured at a nickel and palladium works near the city of Norilsk in northern Siberia, spilling thousands of tonnes of diesel into the nearby Ambarnaya river.

Worst for years

The storage tank is believed to have been built on permafrost: a state of emergency has been declared for what is being described as one of the worst environmental disasters in recent Russian history. State media say an area stretching over 350 square kilometres is polluted and will take years to clean up.

A series of wildfires, often enveloping hundreds of thousands of hectares of Siberia’s boreal forests, or taiga, have raged in many areas over recent weeks.

In early spring farmers across Siberia often light fires to clear land of dead grass and unwanted vegetation. A combination of high temperatures and strong winds has led to fires blazing out of control. Last year Siberia’s fires are estimated to have destroyed an area of forest the size of Belgium.

“2019 saw a record number of fires over the summer months in Siberia”, says Thomas Smith, an environmental geographer at the London School of Economics (LSE) and a wildfires expert.

“This year, aided by high temperatures and conditions that have promoted growth, the fires started early, though so far their incidence is about average and not as extensive as in 2019.

“Forest fires in this region of the Arctic used to happen about every hundred years and now we’re seeing them every summer”

“But what’s important are the peak summer months: the soils are dry and there’s plenty of fuel, so conditions are favourable for more widespread fires”, Dr Smith told Climate News Network.

One of the regions worst affected is in the south of Siberia, around Lake Baikal, the world’s largest and deepest freshwater lake, where an estimated half a million hectares of forest were destroyed by fire earlier this year.

Evgeny Zinichev, Russia’s emergencies minister, speaks of a critical situation unfolding in Siberia and across Russia’s Far East. “The main reason, of course, is unauthorised and uncontrolled agricultural fires”, he says.

“A less snowy winter, an abnormal winter, and insufficient soil moisture are factors that create the conditions for the transition of landscape fires to settlements.”

Other factors have also led to the spread of wildfires. After weeks of lockdown due to the Covid-19 pandemic, people trapped in often cramped and stiflingly hot apartment blocks have sought freedom in the countryside and forests, camping and lighting barbecues.

Hungry Chinese demand

In Soviet times the taiga was more closely monitored and policed: that system has tended to break down in recent years. The Covid crisis has also drawn attention away from the fires.

Corruption and illegal logging, driven in large part by China’s demand for forest products, is an additional threat to the taiga.

The warming and wildfires are having an impact not only across Siberia but around the world. Its forests act as an enormous carbon sink, storing millions of tonnes of climate-changing greenhouse gases.

Fires and logging release the gases into the atmosphere, creating what scientists call a positive feedback loop – the more gases that are released, the warmer and drier the air becomes, so that more areas of forest are at risk from fire.

“Substantial areas of forest in Siberia are on peat soils”, says Dr Smith. “When these soils dry out, fires go underground, threatening to release large amounts of carbon which can lead to a catastrophic climate event.”

Wide impact

Smoke from the fires is carried by winds to other parts of the globe, trapping warm air near the Earth’s surface. The warm air generated by the fires is also likely to result in a further depletion in ice cover and warming of the Arctic seas.

The temperature rises and the growing incidence of wildfires in Siberia have other effects too.

A recent study published in the journal Scientific Reports says the fires mean that more nutrients, particularly nitrogen, leak into streams and waterways.

“Forest fires in this region of the Arctic used to happen about every hundred years and now we’re seeing them every summer”, says Bianca Rodriguez-Cardona, of the University of New Hampshire, Durham, US, one of the study’s authors.

“This increase in fires leads to more input of inorganic solutes into local streams which can alter the chemistry and trigger issues like increased algal blooms and bacteria that can be harmful to humans who depend on these waterways for drinking water, fishing and their livelihoods.” When these waters reach the Arctic they can also dramatically alter the chemistry of the surrounding seas, says the study. – Climate News Network

A huge swathe of Arctic Russia is changing rapidly as oil leaks, the climate warms and Siberia dries out.

LONDON, 5 June, 2020 – Residents of the small Arctic town of Khatanga have never experienced anything like it: their home is changing at a gallop as Siberia dries out.

Khatanga – population around 3,500 – is well north of the Arctic Circle, with usual daytime temperatures at this time of year hovering round a chilly 0°C. On 22 May the temperature in the town reached 25°C – more than double the record to date.

Global warming is causing profound change across the Arctic, a region which acts like a giant air conditioning system regulating the Earth’s climate.

Temperatures are rising far faster than elsewhere: sea ice cover is rapidly disappearing, valuable fish stocks are moving ever further north in search of colder waters, land around the Arctic perimeter is drying out – particularly across the vast expanse of Siberia.

Permafrost is melting. This week a giant oil tank collapsed and ruptured at a nickel and palladium works near the city of Norilsk in northern Siberia, spilling thousands of tonnes of diesel into the nearby Ambarnaya river.

Worst for years

The storage tank is believed to have been built on permafrost: a state of emergency has been declared for what is being described as one of the worst environmental disasters in recent Russian history. State media say an area stretching over 350 square kilometres is polluted and will take years to clean up.

A series of wildfires, often enveloping hundreds of thousands of hectares of Siberia’s boreal forests, or taiga, have raged in many areas over recent weeks.

In early spring farmers across Siberia often light fires to clear land of dead grass and unwanted vegetation. A combination of high temperatures and strong winds has led to fires blazing out of control. Last year Siberia’s fires are estimated to have destroyed an area of forest the size of Belgium.

“2019 saw a record number of fires over the summer months in Siberia”, says Thomas Smith, an environmental geographer at the London School of Economics (LSE) and a wildfires expert.

“This year, aided by high temperatures and conditions that have promoted growth, the fires started early, though so far their incidence is about average and not as extensive as in 2019.

“Forest fires in this region of the Arctic used to happen about every hundred years and now we’re seeing them every summer”

“But what’s important are the peak summer months: the soils are dry and there’s plenty of fuel, so conditions are favourable for more widespread fires”, Dr Smith told Climate News Network.

One of the regions worst affected is in the south of Siberia, around Lake Baikal, the world’s largest and deepest freshwater lake, where an estimated half a million hectares of forest were destroyed by fire earlier this year.

Evgeny Zinichev, Russia’s emergencies minister, speaks of a critical situation unfolding in Siberia and across Russia’s Far East. “The main reason, of course, is unauthorised and uncontrolled agricultural fires”, he says.

“A less snowy winter, an abnormal winter, and insufficient soil moisture are factors that create the conditions for the transition of landscape fires to settlements.”

Other factors have also led to the spread of wildfires. After weeks of lockdown due to the Covid-19 pandemic, people trapped in often cramped and stiflingly hot apartment blocks have sought freedom in the countryside and forests, camping and lighting barbecues.

Hungry Chinese demand

In Soviet times the taiga was more closely monitored and policed: that system has tended to break down in recent years. The Covid crisis has also drawn attention away from the fires.

Corruption and illegal logging, driven in large part by China’s demand for forest products, is an additional threat to the taiga.

The warming and wildfires are having an impact not only across Siberia but around the world. Its forests act as an enormous carbon sink, storing millions of tonnes of climate-changing greenhouse gases.

Fires and logging release the gases into the atmosphere, creating what scientists call a positive feedback loop – the more gases that are released, the warmer and drier the air becomes, so that more areas of forest are at risk from fire.

“Substantial areas of forest in Siberia are on peat soils”, says Dr Smith. “When these soils dry out, fires go underground, threatening to release large amounts of carbon which can lead to a catastrophic climate event.”

Wide impact

Smoke from the fires is carried by winds to other parts of the globe, trapping warm air near the Earth’s surface. The warm air generated by the fires is also likely to result in a further depletion in ice cover and warming of the Arctic seas.

The temperature rises and the growing incidence of wildfires in Siberia have other effects too.

A recent study published in the journal Scientific Reports says the fires mean that more nutrients, particularly nitrogen, leak into streams and waterways.

“Forest fires in this region of the Arctic used to happen about every hundred years and now we’re seeing them every summer”, says Bianca Rodriguez-Cardona, of the University of New Hampshire, Durham, US, one of the study’s authors.

“This increase in fires leads to more input of inorganic solutes into local streams which can alter the chemistry and trigger issues like increased algal blooms and bacteria that can be harmful to humans who depend on these waterways for drinking water, fishing and their livelihoods.” When these waters reach the Arctic they can also dramatically alter the chemistry of the surrounding seas, says the study. – Climate News Network

Global heating means a wetter and warmer world

A wetter and even warmer world will result from faster global warming. The evidence is in the sands of time.

LONDON, 14 May, 2020 – A warmer world may not be just a wetter one. It may get even warmer as well. New studies suggest the heavier rain that will accompany ever-higher global average atmospheric temperatures is in itself likely to trigger ever more carbon dioxide release from tropical soils.

This is what engineers call positive feedback. The very symptoms of a warming world become part of the fuel for accelerating global temperature change.

And the warning is derived not just from models of climate change, but once again from evidence from the past.

Scientists from the US, Canada and Switzerland report in the journal Nature that for the past 18,000 years, the “time of residence” of carbon in the soils of the Ganges-Brahmaputra river basin has been controlled by India’s summer monsoon rainfall.

The lower the rainfall, the higher the length of stored carbon. But as levels of downpour go up, so does the activity of the microbes that turn vegetable matter back into carbon dioxide, and the levels of stored soil carbon go down.

“Climate change is likely to increase rainfall in tropical regions, further accelerating respiration of soil carbon, and adding even more CO2 to the atmosphere”

Right now, global atmospheric concentrations of carbon dioxide have risen from 285 parts per million – the average for most of human history – to 416 ppm as humans clear ever more forest and burn ever more fossil fuels. This 416ppm adds up to about 750 billion tonnes of carbon. The planet’s soils are home to an estimated 3,500 bn tonnes: more than four times as much.

“Our results suggest that future hydroclimate changes in tropical regions are likely to accelerate soil carbon destabilisation, further increasing carbon dioxide concentrations,” the scientists warn.

As temperatures rise, the atmosphere’s capacity to absorb moisture also increases. As temperatures rise, so does direct evaporation from oceans, lakes, rivers and soils. This water vapour will eventually fall as rain, but unevenly: those regions already rainy will become rainier, while drylands are likely to become increasingly arid.

The Ganges and Brahmaputra carry more than a billion tonnes of sediment – most of it eroded from the Himalayan mountain chain – into the Bay of Bengal each year, and cores of sediment taken from the sea floor provide a good record of climate conditions for the last 18,000 years, as the Ice Age began to wane, and the glaciers retreated to permit a hunter-gatherer species to cultivate cereals, domesticate animals, build permanent settlements and found human civilisation.

Radiocarbon readings mean that researchers can date the sediments, and preserved organic molecules from land plants provide an indicator of conditions at those dates.

Methane adds speed

Scientists have repeatedly warned that climate change in the Arctic – the fastest-warming zone of all – is likely to be matched by the release of soil carbon in the form of the greenhouse gas methane from the thawing permafrost, to accelerate yet more warming.

As the once-frozen ground warms up, and vegetation moves further and further north, an estimated 600 million tonnes of carbon is released into the atmosphere every year.

Now, and for different reasons, the same could be true of the tropics, and the evidence is in the sands of time, deposited by one of the world’s great river systems. As the Ice Age ended, monsoon rains began to increase and in 2,600 years soil respiration – and therefore carbon release – doubled. Since then, monsoon rainfall has increased threefold.

“We found that shifts toward a warmer and wetter climate in the drainage basin of the Ganges and Brahmaputra rivers over the last 18,000 years enhanced rates of soil respiration and decreased stocks of soil carbon,” said Christopher Hein, of the Virginia Institute of Marine Science, who led the study.

“This has direct implications for the Earth’s future, as climate change is likely to increase rainfall in tropical regions, further accelerating respiration of soil carbon, and adding even more CO2 to the atmosphere than that directly added by humans.” – Climate News Network

A wetter and even warmer world will result from faster global warming. The evidence is in the sands of time.

LONDON, 14 May, 2020 – A warmer world may not be just a wetter one. It may get even warmer as well. New studies suggest the heavier rain that will accompany ever-higher global average atmospheric temperatures is in itself likely to trigger ever more carbon dioxide release from tropical soils.

This is what engineers call positive feedback. The very symptoms of a warming world become part of the fuel for accelerating global temperature change.

And the warning is derived not just from models of climate change, but once again from evidence from the past.

Scientists from the US, Canada and Switzerland report in the journal Nature that for the past 18,000 years, the “time of residence” of carbon in the soils of the Ganges-Brahmaputra river basin has been controlled by India’s summer monsoon rainfall.

The lower the rainfall, the higher the length of stored carbon. But as levels of downpour go up, so does the activity of the microbes that turn vegetable matter back into carbon dioxide, and the levels of stored soil carbon go down.

“Climate change is likely to increase rainfall in tropical regions, further accelerating respiration of soil carbon, and adding even more CO2 to the atmosphere”

Right now, global atmospheric concentrations of carbon dioxide have risen from 285 parts per million – the average for most of human history – to 416 ppm as humans clear ever more forest and burn ever more fossil fuels. This 416ppm adds up to about 750 billion tonnes of carbon. The planet’s soils are home to an estimated 3,500 bn tonnes: more than four times as much.

“Our results suggest that future hydroclimate changes in tropical regions are likely to accelerate soil carbon destabilisation, further increasing carbon dioxide concentrations,” the scientists warn.

As temperatures rise, the atmosphere’s capacity to absorb moisture also increases. As temperatures rise, so does direct evaporation from oceans, lakes, rivers and soils. This water vapour will eventually fall as rain, but unevenly: those regions already rainy will become rainier, while drylands are likely to become increasingly arid.

The Ganges and Brahmaputra carry more than a billion tonnes of sediment – most of it eroded from the Himalayan mountain chain – into the Bay of Bengal each year, and cores of sediment taken from the sea floor provide a good record of climate conditions for the last 18,000 years, as the Ice Age began to wane, and the glaciers retreated to permit a hunter-gatherer species to cultivate cereals, domesticate animals, build permanent settlements and found human civilisation.

Radiocarbon readings mean that researchers can date the sediments, and preserved organic molecules from land plants provide an indicator of conditions at those dates.

Methane adds speed

Scientists have repeatedly warned that climate change in the Arctic – the fastest-warming zone of all – is likely to be matched by the release of soil carbon in the form of the greenhouse gas methane from the thawing permafrost, to accelerate yet more warming.

As the once-frozen ground warms up, and vegetation moves further and further north, an estimated 600 million tonnes of carbon is released into the atmosphere every year.

Now, and for different reasons, the same could be true of the tropics, and the evidence is in the sands of time, deposited by one of the world’s great river systems. As the Ice Age ended, monsoon rains began to increase and in 2,600 years soil respiration – and therefore carbon release – doubled. Since then, monsoon rainfall has increased threefold.

“We found that shifts toward a warmer and wetter climate in the drainage basin of the Ganges and Brahmaputra rivers over the last 18,000 years enhanced rates of soil respiration and decreased stocks of soil carbon,” said Christopher Hein, of the Virginia Institute of Marine Science, who led the study.

“This has direct implications for the Earth’s future, as climate change is likely to increase rainfall in tropical regions, further accelerating respiration of soil carbon, and adding even more CO2 to the atmosphere than that directly added by humans.” – Climate News Network

North Pole may be clear water by mid-century

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

Within 30 years, there could be clear blue water over the North Pole – not good news for most of the planet.

LONDON, 25 April, 2020 – Within three decades, the North Pole could be free of sea ice in the late summer. The latest and most advanced climate simulations, tested by 21 research institutes from around the world, predict that if humans go on emitting ever-greater volumes of carbon dioxide from fossil fuel combustion and other actions, then before 2050, for the first time in human history, there could be no ice over the North Pole.

And a team of research scientists aboard a ship intent on spending a year observing the drift of sea ice across the Arctic Ocean has been warned that they may have to finish early: the ice supposed to hold the ship fast could melt too soon.

The loss of sea ice promises devastating consequences for the rich life in the most northern waters. The ice reflects sunlight back into space and keeps the Arctic cool. It also provides space for seals on which to haul out, and hunting grounds for blubber-hungry polar bears.

And although human inaction in the climate emergency makes the loss of polar ice ever more probable, so much greenhouse gas has already built up in the planetary atmosphere that it could happen anyway.

Taken aback

“If we reduce global emissions rapidly and substantially, and thus keep our warming below 2°C relative to pre-industrial levels, sea ice will nevertheless likely disappear occasionally in summer even before 2050,” said Dirk Notz, of the University of Hamburg in Germany, who led the study. “This really surprised us.”

Climate scientists first warned of the accelerating loss of Arctic sea ice two decades ago, and have repeatedly re-examined the climate predictions, each time with much the same outcome.

The loss of ice promises new trade routes between Atlantic and Pacific Oceans, but the cost of a warming Arctic could have catastrophic economic consequences.

The pattern of the northern hemisphere climate is driven by the temperature difference between the Arctic and the tropics, and rapid polar warming both disturbs temperate climate regimes and brings ever higher sea levels, with accelerating ice loss from Greenland, which right now bears enough ice to raise global sea levels by more than seven metres.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today”

Dr Notz and his co-authors report in the journal Geophysical Research Letters that they used the very latest climate model developed for the Intergovernmental Panel on Climate Change and tested it on a range of 40 possible climate outcomes.

In most simulations, the Arctic sea ice was reduced to less than a million square kilometres – polar researchers call this “practically sea-ice free” – in the month of September for the first time before 2050. Even if human fossil fuel use was sharply reduced, the ocean could be free of ice some years; if not, the pole could become open water most years.

And a second study, in the journal The Cryosphere, offers a measure of the sea ice loss even now. More than a century ago, the great explorer Fridtjof Nansen sailed his ship the Fram into the polar ice, became fast, and travelled with the floe across the Arctic Ocean.

His became the first scientific observation of a phenomenon called the trans-Polar drift, which takes algae, sediments and nutrients – and increasingly, plastic pollution – across the Arctic from Siberia to Canada and Greenland.

Melted out

In October a team of international researchers boarded a vessel called Polarstern with the intention of measuring the ice movement in the modern Arctic in more detail. They had planned for a year fast in the ice. Their project even has a name: Mosaic, or Multidisciplinary drifting Observatory for the Study of Arctic Climate.

But climate simulations by the US scientists reveal that in every sense, the project is on thin ice and could end prematurely. The flow of ice could be faster, and carry the ship further, than expected: nearly one in five of the simulations also predicted that the ship could melt out of the ice in less than a year.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today,” said one of the authors, Marika Holland of the US National Center for Atmospheric Research.

“Now there is thinner ice, which moves more quickly, and there is less snow cover. It is a totally different ice regime.” – Climate News Network

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

Within 30 years, there could be clear blue water over the North Pole – not good news for most of the planet.

LONDON, 25 April, 2020 – Within three decades, the North Pole could be free of sea ice in the late summer. The latest and most advanced climate simulations, tested by 21 research institutes from around the world, predict that if humans go on emitting ever-greater volumes of carbon dioxide from fossil fuel combustion and other actions, then before 2050, for the first time in human history, there could be no ice over the North Pole.

And a team of research scientists aboard a ship intent on spending a year observing the drift of sea ice across the Arctic Ocean has been warned that they may have to finish early: the ice supposed to hold the ship fast could melt too soon.

The loss of sea ice promises devastating consequences for the rich life in the most northern waters. The ice reflects sunlight back into space and keeps the Arctic cool. It also provides space for seals on which to haul out, and hunting grounds for blubber-hungry polar bears.

And although human inaction in the climate emergency makes the loss of polar ice ever more probable, so much greenhouse gas has already built up in the planetary atmosphere that it could happen anyway.

Taken aback

“If we reduce global emissions rapidly and substantially, and thus keep our warming below 2°C relative to pre-industrial levels, sea ice will nevertheless likely disappear occasionally in summer even before 2050,” said Dirk Notz, of the University of Hamburg in Germany, who led the study. “This really surprised us.”

Climate scientists first warned of the accelerating loss of Arctic sea ice two decades ago, and have repeatedly re-examined the climate predictions, each time with much the same outcome.

The loss of ice promises new trade routes between Atlantic and Pacific Oceans, but the cost of a warming Arctic could have catastrophic economic consequences.

The pattern of the northern hemisphere climate is driven by the temperature difference between the Arctic and the tropics, and rapid polar warming both disturbs temperate climate regimes and brings ever higher sea levels, with accelerating ice loss from Greenland, which right now bears enough ice to raise global sea levels by more than seven metres.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today”

Dr Notz and his co-authors report in the journal Geophysical Research Letters that they used the very latest climate model developed for the Intergovernmental Panel on Climate Change and tested it on a range of 40 possible climate outcomes.

In most simulations, the Arctic sea ice was reduced to less than a million square kilometres – polar researchers call this “practically sea-ice free” – in the month of September for the first time before 2050. Even if human fossil fuel use was sharply reduced, the ocean could be free of ice some years; if not, the pole could become open water most years.

And a second study, in the journal The Cryosphere, offers a measure of the sea ice loss even now. More than a century ago, the great explorer Fridtjof Nansen sailed his ship the Fram into the polar ice, became fast, and travelled with the floe across the Arctic Ocean.

His became the first scientific observation of a phenomenon called the trans-Polar drift, which takes algae, sediments and nutrients – and increasingly, plastic pollution – across the Arctic from Siberia to Canada and Greenland.

Melted out

In October a team of international researchers boarded a vessel called Polarstern with the intention of measuring the ice movement in the modern Arctic in more detail. They had planned for a year fast in the ice. Their project even has a name: Mosaic, or Multidisciplinary drifting Observatory for the Study of Arctic Climate.

But climate simulations by the US scientists reveal that in every sense, the project is on thin ice and could end prematurely. The flow of ice could be faster, and carry the ship further, than expected: nearly one in five of the simulations also predicted that the ship could melt out of the ice in less than a year.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today,” said one of the authors, Marika Holland of the US National Center for Atmospheric Research.

“Now there is thinner ice, which moves more quickly, and there is less snow cover. It is a totally different ice regime.” – Climate News Network

Cloudless skies hasten Greenland’s ice loss

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

The bad news about Greenland’s ice loss has just got even worse. Blame it on mischief by blue skies all day long.

LONDON, 22 April, 2020 – Greenland’s ice loss reached record levels in 2019, and scientists think they’ve identified the culprit: the good weather which normally brings the snow-bearing clouds to the High Arctic.

The huge island, the biggest bank of ice in the northern hemisphere, has been losing ice at an ever-increasing rate in a rapidly warming world. Last year it shed more ice than ever, and this time because the skies were unusually clear.

There is enough ice on Greenland to raise global sea levels by more than seven metres. A recent study established that in the years between 1992 and 2018, rates of polar ice loss have risen six-fold, and so much water has flowed off the Greenland ice surface that sea levels have risen by more than 10mm everywhere.

Now a new study by US and Belgian scientists in the journal The Cryosphere confirms that 2019 was even worse. Because of good weather and cloudless skies, only enough snow fell to deposit 50 billion tonnes of ice into the island’s profit-and-loss ice account. The average annual deposit between 1981 and 2010 was about 375bn tonnes.

But glaciers still flowed towards the sea at an ever-increasing rate, summer snow melt continued to flow off the ice sheet, and icebergs continued to calve, so on balance the island lost 600 billion tonnes of ice: enough to raise global sea levels by 1.5mm. This is the biggest overall loss of ice since records in Greenland began in 1948.

“These atmospheric conditions are becoming more and more frequent over the past few decades. It is very likely that this is due to the waviness of the jet stream”

The cause: unusual spells of high atmospheric pressure over the island for unusually long periods of time. That stopped the formation of clouds, and that meant less precipitation, in the form of snow. Snow reflects solar radiation more effectively than ice, so the surface absorbed more heat and melting also accelerated.

The pattern of warm moist clouds trapped over northern Greenland by the heat that would normally radiate off the ice, instead of releasing snow, also emitted their own heat, to make things worse. The worst year for surface melting remains 2012, but the summer of 2019 was a good second.

The implication is that things could get worse, and losses of Greenland ice could accelerate.

“These atmospheric conditions are becoming more and more frequent over the past few decades,” said Marco Tedesco, of the Lamont-Doherty Earth Observatory at the University of Columbia in the US, the lead author.

“It is very likely that this is due to the waviness of the jet stream, which we think is related to, among other things, the disappearance of snow cover in Siberia, the disappearance of sea ice, and the difference in the rate at which temperature is increasing in the Arctic versus the mid-latitudes.” – Climate News Network

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

The bad news about Greenland’s ice loss has just got even worse. Blame it on mischief by blue skies all day long.

LONDON, 22 April, 2020 – Greenland’s ice loss reached record levels in 2019, and scientists think they’ve identified the culprit: the good weather which normally brings the snow-bearing clouds to the High Arctic.

The huge island, the biggest bank of ice in the northern hemisphere, has been losing ice at an ever-increasing rate in a rapidly warming world. Last year it shed more ice than ever, and this time because the skies were unusually clear.

There is enough ice on Greenland to raise global sea levels by more than seven metres. A recent study established that in the years between 1992 and 2018, rates of polar ice loss have risen six-fold, and so much water has flowed off the Greenland ice surface that sea levels have risen by more than 10mm everywhere.

Now a new study by US and Belgian scientists in the journal The Cryosphere confirms that 2019 was even worse. Because of good weather and cloudless skies, only enough snow fell to deposit 50 billion tonnes of ice into the island’s profit-and-loss ice account. The average annual deposit between 1981 and 2010 was about 375bn tonnes.

But glaciers still flowed towards the sea at an ever-increasing rate, summer snow melt continued to flow off the ice sheet, and icebergs continued to calve, so on balance the island lost 600 billion tonnes of ice: enough to raise global sea levels by 1.5mm. This is the biggest overall loss of ice since records in Greenland began in 1948.

“These atmospheric conditions are becoming more and more frequent over the past few decades. It is very likely that this is due to the waviness of the jet stream”

The cause: unusual spells of high atmospheric pressure over the island for unusually long periods of time. That stopped the formation of clouds, and that meant less precipitation, in the form of snow. Snow reflects solar radiation more effectively than ice, so the surface absorbed more heat and melting also accelerated.

The pattern of warm moist clouds trapped over northern Greenland by the heat that would normally radiate off the ice, instead of releasing snow, also emitted their own heat, to make things worse. The worst year for surface melting remains 2012, but the summer of 2019 was a good second.

The implication is that things could get worse, and losses of Greenland ice could accelerate.

“These atmospheric conditions are becoming more and more frequent over the past few decades,” said Marco Tedesco, of the Lamont-Doherty Earth Observatory at the University of Columbia in the US, the lead author.

“It is very likely that this is due to the waviness of the jet stream, which we think is related to, among other things, the disappearance of snow cover in Siberia, the disappearance of sea ice, and the difference in the rate at which temperature is increasing in the Arctic versus the mid-latitudes.” – Climate News Network

Poles attract marine life avoiding rising heat

In a warming ocean, some species will swim, others sink. But all agree: the poles attract marine life without exception.

LONDON, 3 April, 2020 − It’s the same the whole world over: everywhere in the oceans of this warming planet, the poles attract marine life.

Molluscs are on the move, haddock are feeling the heat, and penguins are shifting further south. Nautilus are heading north, and plankton are edging towards both poles.

New analysis of marine species has confirmed what commercial fishermen already know to their cost: that as the oceans warm, the sea’s citizens shift their grounds.

Researchers report in the journal Current Biology that they surveyed the evidence assembled in 540 records of 304 widely distributed marine animals over the last century, to find that all of them are shifting their range: away from the equatorial waters, and in both hemispheres nearer to the poles.

In the past century, overall, the world’s oceans have warmed by around 1°C. By 2050, the rise may reach 1.5°C, and all the evidence so far suggests fish and shellfish, along with the microbial creatures at the bottom of the food chain and the marine mammals and seabirds that prey on them all, will have shifted their latitudinal range.

“Both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem”

The greatest abundance of any species, the researchers found, was likely to be at the poleward edge of the preferred range, and the sparsest nearest to the tropical waters.

“The main surprise is how pervasive the effects were. We found the same trend across all groups of marine life we looked at, from plankton to marine invertebrates, and from fish to seabirds,” said Martin Genner, an evolutionary ecologist at the University of Bristol in the UK.

“This matters because it means that climate change is not only leading abundance changes, but intrinsically affecting the performance of species locally. We see species such as the Emperor penguin becoming less abundant as the water becomes too warm at their equatorward edge, and we see some fish such as the European sea bass thriving at their poleward edge, where historically they were uncommon.”

Fish and many marine animals have a preferred range of temperatures, and even seemingly imperceptible shifts can have unpredictable effects. Both individual research and commercial catch data have confirmed a series of shifts in response to global heating.

Winners and losers

Tropical fish are shifting away from the hottest waters, North Sea catches are more likely to be found in north Atlantic waters, and some Mediterranean species have now shifted to the waters of Western Europe.

The latest research suggests that whole ecosystems may be on the move, and with them Atlantic herring and Adelie penguins, loggerhead turtles and phytoplankton.

“Some marine species appear to benefit from climate change, particularly some populations at the poleward limits that are now able to thrive,” said Louise Rutterford, another of the research team at Bristol.

“Meanwhile, some marine life suffers as it is not able to adapt fast enough to survive warming, and this is most noticeable in populations nearer the equator.

“This is concerning, as both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem.” − Climate News Network

In a warming ocean, some species will swim, others sink. But all agree: the poles attract marine life without exception.

LONDON, 3 April, 2020 − It’s the same the whole world over: everywhere in the oceans of this warming planet, the poles attract marine life.

Molluscs are on the move, haddock are feeling the heat, and penguins are shifting further south. Nautilus are heading north, and plankton are edging towards both poles.

New analysis of marine species has confirmed what commercial fishermen already know to their cost: that as the oceans warm, the sea’s citizens shift their grounds.

Researchers report in the journal Current Biology that they surveyed the evidence assembled in 540 records of 304 widely distributed marine animals over the last century, to find that all of them are shifting their range: away from the equatorial waters, and in both hemispheres nearer to the poles.

In the past century, overall, the world’s oceans have warmed by around 1°C. By 2050, the rise may reach 1.5°C, and all the evidence so far suggests fish and shellfish, along with the microbial creatures at the bottom of the food chain and the marine mammals and seabirds that prey on them all, will have shifted their latitudinal range.

“Both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem”

The greatest abundance of any species, the researchers found, was likely to be at the poleward edge of the preferred range, and the sparsest nearest to the tropical waters.

“The main surprise is how pervasive the effects were. We found the same trend across all groups of marine life we looked at, from plankton to marine invertebrates, and from fish to seabirds,” said Martin Genner, an evolutionary ecologist at the University of Bristol in the UK.

“This matters because it means that climate change is not only leading abundance changes, but intrinsically affecting the performance of species locally. We see species such as the Emperor penguin becoming less abundant as the water becomes too warm at their equatorward edge, and we see some fish such as the European sea bass thriving at their poleward edge, where historically they were uncommon.”

Fish and many marine animals have a preferred range of temperatures, and even seemingly imperceptible shifts can have unpredictable effects. Both individual research and commercial catch data have confirmed a series of shifts in response to global heating.

Winners and losers

Tropical fish are shifting away from the hottest waters, North Sea catches are more likely to be found in north Atlantic waters, and some Mediterranean species have now shifted to the waters of Western Europe.

The latest research suggests that whole ecosystems may be on the move, and with them Atlantic herring and Adelie penguins, loggerhead turtles and phytoplankton.

“Some marine species appear to benefit from climate change, particularly some populations at the poleward limits that are now able to thrive,” said Louise Rutterford, another of the research team at Bristol.

“Meanwhile, some marine life suffers as it is not able to adapt fast enough to survive warming, and this is most noticeable in populations nearer the equator.

“This is concerning, as both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem.” − Climate News Network

Northern Europe’s warm water flow may falter

Global heating can stop the flow of Europe’s warm water from the tropics. Happening often during the Ice Ages, it could soon recur.

LONDON, 1 April, 2020 – Oceanographers have confirmed once again that global heating could slow or shut down the flow of currents such as the Gulf Stream, ending northern Europe’s warm water supply with an unexpected and prolonged cold snap.

This time the confidence is based neither on ocean measurements made now, nor complex computer simulations of the future. There is fresh evidence from the sea floor that such an ocean shutdown happened many times in the last half a million years of Ice Ages.

The Gulf Stream is part of a much larger flow of water called the Atlantic Meridional Overturning Circulation, an ocean recycling system that both nourishes marine life and moderates the climate in two hemispheres.

For the last 10,000 years of human history, tropical water has flowed north from the Caribbean and equatorial regions and washed the shores of Europe as far north as Norway, bringing equatorial heat to soften the impact of European winters.

A former UK chief scientist once calculated that the Gulf Stream delivered the warmth of 27,000 power stations and kept Britain about 5°C warmer than its citizens had any right to expect, given the latitude at which they lived.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions”

But as that stretch of the Gulf Stream known to oceanographers as the North Atlantic drift current reaches the Greenland Sea it becomes increasingly colder and saltier and thus more dense, and sinks to the ocean floor, loaded with dissolved atmospheric carbon dioxide and oxygen, to become a southward flow called the North Atlantic Deepwater formation.

And it also mingles with fresh water melting each summer from the Greenland ice sheet. But as the rate of Arctic melting accelerates, more fresh water will plunge into the same sea, with an increasing probability that it will disrupt the ocean cycle, turn off the flow of warm tropical water, and plunge Europe into a prolonged cold spell.

In its most dramatic form, this hypothesis was the basis for a 2004 Hollywood disaster movie called The Day After Tomorrow. Climate scientists are fairly sure that such an event would not mean the sudden advance of glacial ice over much of Europe and North America. But they have repeatedly identified evidence that the flow of the northward current is beginning to weaken.

And the journal Science now carries additional evidence that the ocean circulation was repeatedly interrupted for periods of a century or more during the warm spells or interglacials that have happened during the last 450,000 years.

Shells’ signatures

The signature of ocean change is there in the tiny sea shells from marine creatures called foraminifera that rain down onto the ocean floor to form annual layers of silent testimony to past climates.

When the mix of carbon isotope ratios preserved in them is high, that is a sign that the Atlantic circulation was once vigorous. When it is low, then this overturning circulation is feeble, or has stopped altogether.

The signal from the deep ocean is that when they happen, these disruptions seem to happen very swiftly, and to linger for 100 years or more. And, the scientists say, these interruptions in the flow of the ocean – and with it, the transport of heat from the tropics – happen more easily than previously appreciated, and they occurred in past climate conditions similar to those the world may soon face.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions,” said Yair Rosenthal of Rutgers University in the US, one of the authors.

“Although the disruptions in circulation and possible coolings may be relatively short-lived – lasting maybe a century or more – the consequences might be large.” – Climate News Network

Global heating can stop the flow of Europe’s warm water from the tropics. Happening often during the Ice Ages, it could soon recur.

LONDON, 1 April, 2020 – Oceanographers have confirmed once again that global heating could slow or shut down the flow of currents such as the Gulf Stream, ending northern Europe’s warm water supply with an unexpected and prolonged cold snap.

This time the confidence is based neither on ocean measurements made now, nor complex computer simulations of the future. There is fresh evidence from the sea floor that such an ocean shutdown happened many times in the last half a million years of Ice Ages.

The Gulf Stream is part of a much larger flow of water called the Atlantic Meridional Overturning Circulation, an ocean recycling system that both nourishes marine life and moderates the climate in two hemispheres.

For the last 10,000 years of human history, tropical water has flowed north from the Caribbean and equatorial regions and washed the shores of Europe as far north as Norway, bringing equatorial heat to soften the impact of European winters.

A former UK chief scientist once calculated that the Gulf Stream delivered the warmth of 27,000 power stations and kept Britain about 5°C warmer than its citizens had any right to expect, given the latitude at which they lived.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions”

But as that stretch of the Gulf Stream known to oceanographers as the North Atlantic drift current reaches the Greenland Sea it becomes increasingly colder and saltier and thus more dense, and sinks to the ocean floor, loaded with dissolved atmospheric carbon dioxide and oxygen, to become a southward flow called the North Atlantic Deepwater formation.

And it also mingles with fresh water melting each summer from the Greenland ice sheet. But as the rate of Arctic melting accelerates, more fresh water will plunge into the same sea, with an increasing probability that it will disrupt the ocean cycle, turn off the flow of warm tropical water, and plunge Europe into a prolonged cold spell.

In its most dramatic form, this hypothesis was the basis for a 2004 Hollywood disaster movie called The Day After Tomorrow. Climate scientists are fairly sure that such an event would not mean the sudden advance of glacial ice over much of Europe and North America. But they have repeatedly identified evidence that the flow of the northward current is beginning to weaken.

And the journal Science now carries additional evidence that the ocean circulation was repeatedly interrupted for periods of a century or more during the warm spells or interglacials that have happened during the last 450,000 years.

Shells’ signatures

The signature of ocean change is there in the tiny sea shells from marine creatures called foraminifera that rain down onto the ocean floor to form annual layers of silent testimony to past climates.

When the mix of carbon isotope ratios preserved in them is high, that is a sign that the Atlantic circulation was once vigorous. When it is low, then this overturning circulation is feeble, or has stopped altogether.

The signal from the deep ocean is that when they happen, these disruptions seem to happen very swiftly, and to linger for 100 years or more. And, the scientists say, these interruptions in the flow of the ocean – and with it, the transport of heat from the tropics – happen more easily than previously appreciated, and they occurred in past climate conditions similar to those the world may soon face.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions,” said Yair Rosenthal of Rutgers University in the US, one of the authors.

“Although the disruptions in circulation and possible coolings may be relatively short-lived – lasting maybe a century or more – the consequences might be large.” – Climate News Network