Tag Archives: Oceans

Japan faces another Fukushima disaster crisis

A plan to dump a million tonnes of radioactive water from the Fukushima disaster off Japan is alarming local people.

LONDON, 3 November, 2020 − The Japanese government has an unsolvable problem: what to do with more than a million tonnes of water contaminated with radioactive tritium, in store since the Fukushima disaster and growing at more than 150 tonnes a day.

The water, contained in a thousand giant tanks, has been steadily accumulating since the nuclear accident in 2011. It has been used to cool the three reactors that suffered a meltdown as a result of the tsunami that hit the coast.

Tritium is a radioactive element produced as a by-product by nuclear reactors under normal operation, and is present everywhere in the fabric of the reactor buildings, so water used for cooling them is bound to be contaminated by it.

To avoid another potentially catastrophic meltdown in the remaining fuel the cooling has to continue indefinitely, so the problem continues to worsen. The government has been told that Japan will run out of storage tanks by 2022.

Announcement delayed

As often happens when governments are faced with difficult problems, the unpalatable decision to release the contaminated water into the sea has not been formally announced, but the intention of the government to take this course has been leaked and so widely reported.

Immediately both local and worldwide adverse reaction has resulted. There are the direct effects on the local fishermen who fear that no one will want to buy their catch, but over a wider area the health effects are the main concern.

As ever with the nuclear industry, there are two widely different views on tritium. The Health Physics Society says it is a mildly radioactive element that is present everywhere, and doubts that people will be affected by it. But the Nuclear Information and Resource Service believes tritium is far more dangerous and increases the likelihood of cancers, birth defects and genetic disorders.

The issue is further complicated because the Fukushima wastewater contains a number of other radionuclides, not in such high quantities, but sufficient to cause damage. Ian Fairlie, an independent consultant on radioactivity in the environment, is extremely concerned about Japan’s plans and the health of the local people.

“Ten half-lives for tritium is 123 years: that’s how long these tanks will have to last – at least. This will allow time also for politicians to reflect on the wisdom of their support for nuclear power”

In a detailed assessment of the situation he says other highly dangerous radioactive substances, including caesium-137 and strontium-90, are also in the water stored at Fukushima.

They are in lower quantities than the tritium, he says, but still unacceptably high – up to 100 times above the legally permitted limit. All these radionuclides decay over time − some take thousands of years − but tritium decays faster, the danger from it halving every 12.3 years.

In a briefing for the Nuclear Free Local Authorities (NFLA), a UK based organisation, another independent analyst, Tim Deere-Jones, discusses research that shows that tritium binds with organic material in plants and animals.

This is potentially highly damaging to human health because it travels up the food chain in the marine environment, specifically accumulating in fish. This means fish-eating communities on the Japanese coast could ingest much larger quantities of tritium than some physicists think likely.

Relying on dilution

Tim Deere-Jones is also concerned that the tritium will be blown inshore on the prevailing wind in sea spray and will bio-accumulate in food plants, making it risky to eat crops as far as ten miles inland. Because of the potential dangers of releasing the water the NFLA has asked the Japanese government to reconsider its decision.

The government has not yet responded though, because officially it is still considering what to do. However, it is likely to argue that pumping the contaminated water into the sea is acceptable because it will be diluted millions of times, and anyway seawater does already contain minute quantities of tritium.

Dr Fairlie is among many who think this is too dangerous, but he admits there are no easy solutions.

He says: “Barring a miraculous technical discovery which is unlikely, I think TEPCO/Japanese Gov’t [TEPCO is the Tokyo Electric Power Company, owner of the Fukushima Daiichi plant]  will have to buy more land and keep on building more holding tanks to allow for tritium decay to take place. Ten half-lives for tritium is 123 years: that’s how long these tanks will have to last – at least.

“This will allow time not only for tritium to decay, but also for politicians to reflect on the wisdom of their support for nuclear power.” − Climate News Network

A plan to dump a million tonnes of radioactive water from the Fukushima disaster off Japan is alarming local people.

LONDON, 3 November, 2020 − The Japanese government has an unsolvable problem: what to do with more than a million tonnes of water contaminated with radioactive tritium, in store since the Fukushima disaster and growing at more than 150 tonnes a day.

The water, contained in a thousand giant tanks, has been steadily accumulating since the nuclear accident in 2011. It has been used to cool the three reactors that suffered a meltdown as a result of the tsunami that hit the coast.

Tritium is a radioactive element produced as a by-product by nuclear reactors under normal operation, and is present everywhere in the fabric of the reactor buildings, so water used for cooling them is bound to be contaminated by it.

To avoid another potentially catastrophic meltdown in the remaining fuel the cooling has to continue indefinitely, so the problem continues to worsen. The government has been told that Japan will run out of storage tanks by 2022.

Announcement delayed

As often happens when governments are faced with difficult problems, the unpalatable decision to release the contaminated water into the sea has not been formally announced, but the intention of the government to take this course has been leaked and so widely reported.

Immediately both local and worldwide adverse reaction has resulted. There are the direct effects on the local fishermen who fear that no one will want to buy their catch, but over a wider area the health effects are the main concern.

As ever with the nuclear industry, there are two widely different views on tritium. The Health Physics Society says it is a mildly radioactive element that is present everywhere, and doubts that people will be affected by it. But the Nuclear Information and Resource Service believes tritium is far more dangerous and increases the likelihood of cancers, birth defects and genetic disorders.

The issue is further complicated because the Fukushima wastewater contains a number of other radionuclides, not in such high quantities, but sufficient to cause damage. Ian Fairlie, an independent consultant on radioactivity in the environment, is extremely concerned about Japan’s plans and the health of the local people.

“Ten half-lives for tritium is 123 years: that’s how long these tanks will have to last – at least. This will allow time also for politicians to reflect on the wisdom of their support for nuclear power”

In a detailed assessment of the situation he says other highly dangerous radioactive substances, including caesium-137 and strontium-90, are also in the water stored at Fukushima.

They are in lower quantities than the tritium, he says, but still unacceptably high – up to 100 times above the legally permitted limit. All these radionuclides decay over time − some take thousands of years − but tritium decays faster, the danger from it halving every 12.3 years.

In a briefing for the Nuclear Free Local Authorities (NFLA), a UK based organisation, another independent analyst, Tim Deere-Jones, discusses research that shows that tritium binds with organic material in plants and animals.

This is potentially highly damaging to human health because it travels up the food chain in the marine environment, specifically accumulating in fish. This means fish-eating communities on the Japanese coast could ingest much larger quantities of tritium than some physicists think likely.

Relying on dilution

Tim Deere-Jones is also concerned that the tritium will be blown inshore on the prevailing wind in sea spray and will bio-accumulate in food plants, making it risky to eat crops as far as ten miles inland. Because of the potential dangers of releasing the water the NFLA has asked the Japanese government to reconsider its decision.

The government has not yet responded though, because officially it is still considering what to do. However, it is likely to argue that pumping the contaminated water into the sea is acceptable because it will be diluted millions of times, and anyway seawater does already contain minute quantities of tritium.

Dr Fairlie is among many who think this is too dangerous, but he admits there are no easy solutions.

He says: “Barring a miraculous technical discovery which is unlikely, I think TEPCO/Japanese Gov’t [TEPCO is the Tokyo Electric Power Company, owner of the Fukushima Daiichi plant]  will have to buy more land and keep on building more holding tanks to allow for tritium decay to take place. Ten half-lives for tritium is 123 years: that’s how long these tanks will have to last – at least.

“This will allow time not only for tritium to decay, but also for politicians to reflect on the wisdom of their support for nuclear power.” − Climate News Network

Antarctic depths warm far beyond oceanic average

Heat from factories and car exhausts must go somewhere. A surprising amount is now sunk in the remote Antarctic depths.

LONDON, 28 October, 2020 − Thanks to global heating, a vital part of the Southern Ocean is warming at a rate five times faster than the average for the Blue Planet as a whole, in the far Antarctic depths: 2000 metres or more below the surface of the Weddell Sea.

It is happening because at that depth the Weddell Sea has absorbed five times as much atmospheric heat − fuelled by greenhouse gas emissions from human fossil fuel combustion − as the average for the rest of the ocean. But what happens out of sight and far below the surface may not stay invisible. The Weddell Sea is where vast volumes of water circulate.

The fear is that such dramatic warming at depth could end up weakening a powerful current that encircles Antarctica, according to a new study in the Journal of Climate.

The evidence comes from 30 years of temperature and salinity samples, taken at the same spot and through the entire water column, with exquisite accuracy, by scientists aboard the German research icebreaker Polarstern.

“Our time series confirms the pivotal role of the Southern Ocean and especially the Weddell Sea in terms of storing heat in the depths of the world’s oceans”

“Our data shows a clear division in the water column of the Weddell Sea. While the water in the upper 700 metres has hardly warmed at all, in the deeper regions we’re seeing a consistent temperature rise of 0.0021 to 0.0024 degrees Celsius per year,” said Volker Strass, of the Alfred Wegener Institute in Bremerhaven in Germany.

“Since the ocean has roughly 1,000 times the heat capacity of the atmosphere, these numbers represent an enormous scale of heat absorption. By using the temperature rise to calculate the warming rate in watts per square metre, you can see that over the past 30 years, at depths of over 2,000 metres, the Weddell Sea has absorbed five times as much heat as the rest of the ocean on average.”

The global ocean is the great absorber of atmospheric shock. The deep blue sea has so far absorbed more than nine-tenths of the heat trapped by greenhouse gas emissions in the atmosphere.

The Weddell Sea begins at the extreme south of the Atlantic Ocean: it is roughly 10 times the size of Europe’s North Sea. Here tremendous volumes of water cool down. As sea ice forms on the surface the remaining waters become more salty, and because they have become colder, and denser, sink to the bottom, to spread at depth to drive deep sea flow into the oceans.

Ocean circulation risk

This act of overturning − the sinking of surface waters for thousands of metres into the Antarctic depths − is part of the machinery of ocean circulation that drives and modifies the world’s weather systems, and the climate.

The problem is that if the bottom waters are warming − and are therefore less dense − then this could weaken or stall the mechanism for ocean circulation. In the past 30 years the prevailing winds have shifted and intensified, and the flow speed of ocean water has increased to deliver more heat to the Weddell Sea with each decade.

Warming ocean waters have already been implicated in the loss of sea ice  cover that normally slows the flow of Antarctica’s continental glaciers. And warming in the Arctic has already triggered worries about the future of the “Atlantic Conveyer,” that enormous circulation of water that distributes heat from the Equator to the Poles and keeps northern Europe much warmer than its latitudes would dictate.

“Our time series confirms the pivotal role of the Southern Ocean and especially the Weddell Sea in terms of storing heat in the depths of the world’s oceans,” said Dr Strass. − Climate News Network

Heat from factories and car exhausts must go somewhere. A surprising amount is now sunk in the remote Antarctic depths.

LONDON, 28 October, 2020 − Thanks to global heating, a vital part of the Southern Ocean is warming at a rate five times faster than the average for the Blue Planet as a whole, in the far Antarctic depths: 2000 metres or more below the surface of the Weddell Sea.

It is happening because at that depth the Weddell Sea has absorbed five times as much atmospheric heat − fuelled by greenhouse gas emissions from human fossil fuel combustion − as the average for the rest of the ocean. But what happens out of sight and far below the surface may not stay invisible. The Weddell Sea is where vast volumes of water circulate.

The fear is that such dramatic warming at depth could end up weakening a powerful current that encircles Antarctica, according to a new study in the Journal of Climate.

The evidence comes from 30 years of temperature and salinity samples, taken at the same spot and through the entire water column, with exquisite accuracy, by scientists aboard the German research icebreaker Polarstern.

“Our time series confirms the pivotal role of the Southern Ocean and especially the Weddell Sea in terms of storing heat in the depths of the world’s oceans”

“Our data shows a clear division in the water column of the Weddell Sea. While the water in the upper 700 metres has hardly warmed at all, in the deeper regions we’re seeing a consistent temperature rise of 0.0021 to 0.0024 degrees Celsius per year,” said Volker Strass, of the Alfred Wegener Institute in Bremerhaven in Germany.

“Since the ocean has roughly 1,000 times the heat capacity of the atmosphere, these numbers represent an enormous scale of heat absorption. By using the temperature rise to calculate the warming rate in watts per square metre, you can see that over the past 30 years, at depths of over 2,000 metres, the Weddell Sea has absorbed five times as much heat as the rest of the ocean on average.”

The global ocean is the great absorber of atmospheric shock. The deep blue sea has so far absorbed more than nine-tenths of the heat trapped by greenhouse gas emissions in the atmosphere.

The Weddell Sea begins at the extreme south of the Atlantic Ocean: it is roughly 10 times the size of Europe’s North Sea. Here tremendous volumes of water cool down. As sea ice forms on the surface the remaining waters become more salty, and because they have become colder, and denser, sink to the bottom, to spread at depth to drive deep sea flow into the oceans.

Ocean circulation risk

This act of overturning − the sinking of surface waters for thousands of metres into the Antarctic depths − is part of the machinery of ocean circulation that drives and modifies the world’s weather systems, and the climate.

The problem is that if the bottom waters are warming − and are therefore less dense − then this could weaken or stall the mechanism for ocean circulation. In the past 30 years the prevailing winds have shifted and intensified, and the flow speed of ocean water has increased to deliver more heat to the Weddell Sea with each decade.

Warming ocean waters have already been implicated in the loss of sea ice  cover that normally slows the flow of Antarctica’s continental glaciers. And warming in the Arctic has already triggered worries about the future of the “Atlantic Conveyer,” that enormous circulation of water that distributes heat from the Equator to the Poles and keeps northern Europe much warmer than its latitudes would dictate.

“Our time series confirms the pivotal role of the Southern Ocean and especially the Weddell Sea in terms of storing heat in the depths of the world’s oceans,” said Dr Strass. − Climate News Network

Geology’s human footprint is enough to spur rage

Once again science has presented evidence that a new geological epoch is here. This human footprint is all our own work.

LONDON, 21 October, 2020 − The human footprint has left its mark on Earth, in every sense. The United States alone is scarred by 500,000 abandoned mines and quarries.

Right now, worldwide, there are more than 500,000 active quarries and pits, employing 4 million people, excavating the sand and gravel needed for new roads, new homes and new megacities.

Humans have not simply pitted the face of the Earth, they have paved it. In 1904, beyond the cities, the US had just 225 km of sealed highway. Now it has 4.3m km of asphalt or concrete roadway, consuming more than 20 billion tonnes of sand and gravel.

By comparison, the Great Wall of China, the biggest and most enduring construction in early human history, contains just 0.4bn tonnes of stone.

Humans have changed the face of the waters. In 1950, trawlers, long-liners and purse seiners fished just 1% of the high seas beyond territorial waters. No fish species of any kind was considered over-exploited or depleted.

Extinction threat widens

Less than one human lifetime on, fishing fleets roam 63% of the high seas and 87% of fish species are exploited, over-exploited or in a state of collapse. Meanwhile somewhere between 5m and almost 13 million tons of discarded plastics flow each year into the sea.

Humans and human livestock now far outweigh all other mammalian life. At least 96% of the mass of all mammals is represented by humans and their domesticated animals. Domestic poultry makes up 70% of the mass of all living birds. The natural world is now endangered, with a million species at risk of extinction.

And humans have left an almost indelible radiant signature over the entire global surface: between 1950 and 1980, nations detonated more than 500 thermonuclear weapons to smear the air and surface of the planet with radioactive materials: one of these, plutonium-239, will be detectable for the next 100,000 years.

The catalogue of planetary devastation that is the human footprint is assembled in a new study by US and European scientists in the journal Nature Communications: Earth and Environment. It is part of a fresh attempt to settle a seemingly academic question of geological bureaucracy, the naming of ages.

“We humans collectively got ourselves into this mess, we need to work together to reverse these environmental trends and dig ourselves out of it”

The 11,000-year interval since the end of the last Ice Age and the dawn of agriculture, metal smelting, and the first cities, cultures and empires is still formally identified as the Holocene. The latest study of the human legacy is just another salvo in the campaign to announce and confirm the launch of an entirely new epoch, to be called the Anthropocene.

In fact, environmental campaigners, biologists and geophysicists have for years been informally calling the last six or seven decades the Anthropocene. But the authority with the last word on internationally-agreed geological labels − the International Commission on Stratigraphy − has yet to confirm the launch of the new geological epoch.

To help confirm the case for change, researchers have once again assembled the evidence and identified at least 16 ways in which humans have dramatically altered the planet since 1950, and the beginning of what is sometimes called The Great Acceleration.

For instance, humans have doubled the quantity of fixed nitrogen in the biosphere, created an alarming hole in the stratospheric ozone layer, released enough gases to raise the planetary temperature and precipitate global climate change, fashioned or forged perhaps 180,000 kinds of mineral (by comparison, only about 5,300 occur naturally) and − with dams, drains, wells, irrigation, and hydraulic engineering − effectively replumbed the world’s river systems.

Ineradicable scar

By forging metals and building structures, humans have become the greatest earth-moving force on the planet, and left a mark that will endure for aeons.

Altogether, humans have altered the world’s rivers, lakes, coastlines, vegetation, soils, chemistry and climate. The study makes grim reading.

“This is the first time that humans have documented humanity’s geological footprint on such a comprehensive scale in a single publication,” said Jaia Syvitski, of the University of Colorado, Boulder, who led the research team that assembled the evidence.

“We humans collectively got ourselves into this mess, we need to work together to reverse these environmental trends and dig ourselves out of it.

“Society shouldn’t feel complacent. Few people who read the manuscript should come away without emotions bubbling up, like rage, grief and even fear.” − Climate News Network

Once again science has presented evidence that a new geological epoch is here. This human footprint is all our own work.

LONDON, 21 October, 2020 − The human footprint has left its mark on Earth, in every sense. The United States alone is scarred by 500,000 abandoned mines and quarries.

Right now, worldwide, there are more than 500,000 active quarries and pits, employing 4 million people, excavating the sand and gravel needed for new roads, new homes and new megacities.

Humans have not simply pitted the face of the Earth, they have paved it. In 1904, beyond the cities, the US had just 225 km of sealed highway. Now it has 4.3m km of asphalt or concrete roadway, consuming more than 20 billion tonnes of sand and gravel.

By comparison, the Great Wall of China, the biggest and most enduring construction in early human history, contains just 0.4bn tonnes of stone.

Humans have changed the face of the waters. In 1950, trawlers, long-liners and purse seiners fished just 1% of the high seas beyond territorial waters. No fish species of any kind was considered over-exploited or depleted.

Extinction threat widens

Less than one human lifetime on, fishing fleets roam 63% of the high seas and 87% of fish species are exploited, over-exploited or in a state of collapse. Meanwhile somewhere between 5m and almost 13 million tons of discarded plastics flow each year into the sea.

Humans and human livestock now far outweigh all other mammalian life. At least 96% of the mass of all mammals is represented by humans and their domesticated animals. Domestic poultry makes up 70% of the mass of all living birds. The natural world is now endangered, with a million species at risk of extinction.

And humans have left an almost indelible radiant signature over the entire global surface: between 1950 and 1980, nations detonated more than 500 thermonuclear weapons to smear the air and surface of the planet with radioactive materials: one of these, plutonium-239, will be detectable for the next 100,000 years.

The catalogue of planetary devastation that is the human footprint is assembled in a new study by US and European scientists in the journal Nature Communications: Earth and Environment. It is part of a fresh attempt to settle a seemingly academic question of geological bureaucracy, the naming of ages.

“We humans collectively got ourselves into this mess, we need to work together to reverse these environmental trends and dig ourselves out of it”

The 11,000-year interval since the end of the last Ice Age and the dawn of agriculture, metal smelting, and the first cities, cultures and empires is still formally identified as the Holocene. The latest study of the human legacy is just another salvo in the campaign to announce and confirm the launch of an entirely new epoch, to be called the Anthropocene.

In fact, environmental campaigners, biologists and geophysicists have for years been informally calling the last six or seven decades the Anthropocene. But the authority with the last word on internationally-agreed geological labels − the International Commission on Stratigraphy − has yet to confirm the launch of the new geological epoch.

To help confirm the case for change, researchers have once again assembled the evidence and identified at least 16 ways in which humans have dramatically altered the planet since 1950, and the beginning of what is sometimes called The Great Acceleration.

For instance, humans have doubled the quantity of fixed nitrogen in the biosphere, created an alarming hole in the stratospheric ozone layer, released enough gases to raise the planetary temperature and precipitate global climate change, fashioned or forged perhaps 180,000 kinds of mineral (by comparison, only about 5,300 occur naturally) and − with dams, drains, wells, irrigation, and hydraulic engineering − effectively replumbed the world’s river systems.

Ineradicable scar

By forging metals and building structures, humans have become the greatest earth-moving force on the planet, and left a mark that will endure for aeons.

Altogether, humans have altered the world’s rivers, lakes, coastlines, vegetation, soils, chemistry and climate. The study makes grim reading.

“This is the first time that humans have documented humanity’s geological footprint on such a comprehensive scale in a single publication,” said Jaia Syvitski, of the University of Colorado, Boulder, who led the research team that assembled the evidence.

“We humans collectively got ourselves into this mess, we need to work together to reverse these environmental trends and dig ourselves out of it.

“Society shouldn’t feel complacent. Few people who read the manuscript should come away without emotions bubbling up, like rage, grief and even fear.” − 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

Wilder shores of science yield new ideas on climate

New ideas on climate mean earthquake scientists know more about global heating and astronomers worry over rising warmth.

LONDON, 22 September, 2020 – Science has extended research into the global heating crisis, thanks to new ideas on climate. And, conversely, climate change has extended science in unexpected ways.

Seismologists believe they may have a new way to take the temperature of the world’s oceans. And astronomers focused on distant galaxies have unwittingly amassed a 30-year record of climate change in the Earth’s own atmosphere.

Both discoveries, in the same week, start with the simple physics of sight and sound. US and Chinese researchers report in the journal Science that records from submarine earthquakes could now deliver an unexpected way of measuring the warmth of the water.

Submarine earthquakes create a pattern of sound that can be transmitted immense distances through the ocean without much weakening. And, since the speed of sound in water increases as the temperature of the water rises, the length of time the sound takes to reach detector equipment is itself an indicator of ocean temperature.

Seismologists know – from waves travelling through the Earth’s crust and its deep interior – when and where the earthquakes happen. Seismic waves sprint through rock at rates measured in kilometres per second. Sound waves propagate through oceans at rates measured in kilometres per hour.

“It is of prime importance that astronomy uses its unique perspective to claim this simple fact: there is no planet B”

Just as the differences between the speed of lightning and the speed of thunder can establish the distance of an electrical storm, so if researchers know the time and distance of the sea floor event, they have a way of taking the temperature of the water. The constant rumbling of a living planet could offer a new set of easily assembled readings.

“The key is that we use repeating earthquakes – earthquakes that happen again and again in the same place,” said Wenbo Wu, of the California Institute of Technology, who led the Science study.

“We’re looking at earthquakes that occur off Sumatra in Indonesia, and we measure when they arrive in the central Indian Ocean. It takes about half an hour for them to travel that distance, with water temperature causing about one tenth of a second difference. It’s a very small fractional change, but we can measure it.”

The finding matters because – although humans have been recording local ground and air temperatures for at least 300 years, and worldwide for more than a century – it is much harder to be sure about ocean temperatures: the seas cover 70% of the planet, to an average depth of more than 3 kms, and the temperatures vary with both depth and latitude.

Sound goes deep

Oceanographic research is costly, technically challenging, and uneven. Researchers know that the oceans are responding to climate change driven by global heating as a consequence of greenhouse gas emissions: they do not, however, yet have an assured measure of how much heat the oceans have absorbed, and will go on absorbing.

“The ocean plays a role in the rate that the climate is changing,” said Jörn Callies of Caltech, a co-author. “The ocean is the main reservoir of energy in the climate system, and the deep ocean in particular is important to monitor. One advantage of our method is that the sound waves sample depths below 2,000 metres where there are very few conventional measurements.”

Paradoxically, astronomers need to know a great deal about the first few thousand metres of planet Earth as they peer into the furthest reaches of the universe: what they see and how well they see it is affected by atmospheric temperature, turbulence and moisture.

As ground-based telescopes become bigger and more sensitive – the Extremely Large Telescope now under construction at Paranal in northern Chile will collect light with a mirror 39 metres across – so do the challenges of eliminating the atmospheric turbulence that puts the twinkle in the stars of the night sky: cold air and warm air refract light differently, to create a blur. The bigger the telescope, the greater will be the problem of blur.

For three decades, scientists in the highest and driest part of Chile have been recording subtle and not so subtle atmospheric change. And according to the journal Nature Astronomy, climate change is already beginning to affect astronomical research, and will go on creating problems.

Terrestrial disturbances

“The data showed a 1.5°C increase in near-ground temperature over the last four decades at the Paranal Observatory,” said Susanne Crewell of the University of Cologne. “This is slightly higher than the worldwide average of 1°C since the pre-industrial age.”

Average wind speeds – wind also affects the precision of observations – have increased by 3 or 4 metres per second in the same period. Humidity, too, is expected to change as the world moves to what could be a 4°C average rise in temperature by the century’s end.

The message is that conditions on Earth can disturb the observations and mask the understanding of events billions of light years away and billions of years ago. Astronomers, too, need to sound the alarm about climate change, she and her colleagues write.

“To do so, a massive cultural shift is needed,” they conclude, “and it is of prime importance that astronomy uses its unique perspective to claim this simple fact: there is no planet B.” – Climate News Network

New ideas on climate mean earthquake scientists know more about global heating and astronomers worry over rising warmth.

LONDON, 22 September, 2020 – Science has extended research into the global heating crisis, thanks to new ideas on climate. And, conversely, climate change has extended science in unexpected ways.

Seismologists believe they may have a new way to take the temperature of the world’s oceans. And astronomers focused on distant galaxies have unwittingly amassed a 30-year record of climate change in the Earth’s own atmosphere.

Both discoveries, in the same week, start with the simple physics of sight and sound. US and Chinese researchers report in the journal Science that records from submarine earthquakes could now deliver an unexpected way of measuring the warmth of the water.

Submarine earthquakes create a pattern of sound that can be transmitted immense distances through the ocean without much weakening. And, since the speed of sound in water increases as the temperature of the water rises, the length of time the sound takes to reach detector equipment is itself an indicator of ocean temperature.

Seismologists know – from waves travelling through the Earth’s crust and its deep interior – when and where the earthquakes happen. Seismic waves sprint through rock at rates measured in kilometres per second. Sound waves propagate through oceans at rates measured in kilometres per hour.

“It is of prime importance that astronomy uses its unique perspective to claim this simple fact: there is no planet B”

Just as the differences between the speed of lightning and the speed of thunder can establish the distance of an electrical storm, so if researchers know the time and distance of the sea floor event, they have a way of taking the temperature of the water. The constant rumbling of a living planet could offer a new set of easily assembled readings.

“The key is that we use repeating earthquakes – earthquakes that happen again and again in the same place,” said Wenbo Wu, of the California Institute of Technology, who led the Science study.

“We’re looking at earthquakes that occur off Sumatra in Indonesia, and we measure when they arrive in the central Indian Ocean. It takes about half an hour for them to travel that distance, with water temperature causing about one tenth of a second difference. It’s a very small fractional change, but we can measure it.”

The finding matters because – although humans have been recording local ground and air temperatures for at least 300 years, and worldwide for more than a century – it is much harder to be sure about ocean temperatures: the seas cover 70% of the planet, to an average depth of more than 3 kms, and the temperatures vary with both depth and latitude.

Sound goes deep

Oceanographic research is costly, technically challenging, and uneven. Researchers know that the oceans are responding to climate change driven by global heating as a consequence of greenhouse gas emissions: they do not, however, yet have an assured measure of how much heat the oceans have absorbed, and will go on absorbing.

“The ocean plays a role in the rate that the climate is changing,” said Jörn Callies of Caltech, a co-author. “The ocean is the main reservoir of energy in the climate system, and the deep ocean in particular is important to monitor. One advantage of our method is that the sound waves sample depths below 2,000 metres where there are very few conventional measurements.”

Paradoxically, astronomers need to know a great deal about the first few thousand metres of planet Earth as they peer into the furthest reaches of the universe: what they see and how well they see it is affected by atmospheric temperature, turbulence and moisture.

As ground-based telescopes become bigger and more sensitive – the Extremely Large Telescope now under construction at Paranal in northern Chile will collect light with a mirror 39 metres across – so do the challenges of eliminating the atmospheric turbulence that puts the twinkle in the stars of the night sky: cold air and warm air refract light differently, to create a blur. The bigger the telescope, the greater will be the problem of blur.

For three decades, scientists in the highest and driest part of Chile have been recording subtle and not so subtle atmospheric change. And according to the journal Nature Astronomy, climate change is already beginning to affect astronomical research, and will go on creating problems.

Terrestrial disturbances

“The data showed a 1.5°C increase in near-ground temperature over the last four decades at the Paranal Observatory,” said Susanne Crewell of the University of Cologne. “This is slightly higher than the worldwide average of 1°C since the pre-industrial age.”

Average wind speeds – wind also affects the precision of observations – have increased by 3 or 4 metres per second in the same period. Humidity, too, is expected to change as the world moves to what could be a 4°C average rise in temperature by the century’s end.

The message is that conditions on Earth can disturb the observations and mask the understanding of events billions of light years away and billions of years ago. Astronomers, too, need to sound the alarm about climate change, she and her colleagues write.

“To do so, a massive cultural shift is needed,” they conclude, “and it is of prime importance that astronomy uses its unique perspective to claim this simple fact: there is no planet B.” – Climate News Network

Seas and forests are muddying the carbon budget

As climates change, forests may not absorb more carbon as expected. But a new carbon budget could appeal to the oceans.

LONDON, 18 September 2020 – Two new studies could throw long-term climate forecasts into confusion. The planetary carbon budget – the all-important traffic of life’s first element between rocks, water, atmosphere and living things – that underpins planetary temperatures and maintains a stable climate needs a rethink.

A warming climate makes trees grow faster. The awkward finding is that  faster-growing trees die younger. Therefore they must surrender their carbon back to the atmosphere quicker.

So tomorrow’s forests may not be quite such reliable long-term banks of carbon pumped into the atmosphere as a consequence of profligate fossil fuel use by human economies.

The more reassuring news is that the ocean – that’s almost three fourths of the planet’s surface – may absorb and store a lot more atmospheric carbon than previous estimates suggest.

All calculations about the future rate of global heating, and the potential consequences of climate change, rest upon the carbon budget.

Forest doubts

This is the intricate accounting of the mass of carbon in continuous circulation from air to plant to animal and then to shell, skeleton and sediment, and the expected flow of carbon emissions from the combustion of fossil fuels stored hundreds of millions of years ago, and exhumed in the last two centuries.

To make sense of the factors at work, climate scientists have to make calculations about all the carbon stored in the permafrost, in the soils, in the forests, dissolved in the oceans, free in the atmosphere and being released from power station chimneys, vehicle exhausts and ploughed or scorched land.

But for decades, one component of the equation has been automatically accepted: more forests must mean more carbon absorbed, and better protected natural forests would store the most carbon, the most efficiently.

Now a new report in the journal Nature Communications introduces some doubt into this cornerstone of the carbon budget. In an already warming world, much more of the carbon stored in tomorrow’s forests might find its way back into the atmosphere.

Researchers looked at 200,000 tree ring records from 82 tree species from sites around the planet. They found what they describe as trade-offs that are near universal: faster-growing trees have shorter lives.

“There is likely to be a timelag before we see the worst of the potential loss of carbon stocks from increases in tree mortality”

This was true in cool climates and warm ones, and in all species. So the hope that natural vegetation will respond to warmer temperatures by absorbing even more carbon becomes insecure, especially if it means that the more vigorous growth means simply swifter death and decay.

“Our modeling suggests that there is likely to be a timelag before we see the worst of the potential loss of carbon stocks from increases in tree mortality,” said Roel Brienen of the University of Leeds in the UK, who led the research. “They estimate that global increases in tree death don’t kick in until after sites show accelerated growth.”

All such research is provisional: the findings gain currency only when supported by other teams using different approaches. So it has yet to be confirmed.

But recent studies have suggested that climate change has already begun to complicate calculations. Just in recent months, research teams have found that forest trees are growing shorter and dying younger; that higher temperatures may affect plant germination; and that forests already hit by drought may start surrendering carbon more swiftly than they absorb it. Planting more trees is not an alternative to reducing greenhouse gas emissions.

On the other hand, the carbon budget may still make sense: the oceans may be responding to ever-higher concentrations of carbon dioxide by absorbing more from the atmosphere, which also makes the oceans more acidic, which is not necessarily helpful.

Oceans’ effect

All such calculations are based on sea surface temperatures. Gases such as carbon dioxide and oxygen dissolve well in colder water, not so well in warm lagoons and tropical tides.

But a British group reports in the same journal that calculations so far may have been under-estimates. This is because, on balance, researchers have tended to ignore the small difference between the temperatures at the surface, and a few metres down, where the measurements of dissolved greenhouse gas were actually made.

A team from the University of Exeter worked from a global database to make new estimates of the oceans’ appetite for carbon between 1992 and 2018.

“We used satellite data to correct for these temperature differences, and when we do that, it makes a big difference – we get a substantially larger flux going into the ocean,” said Andrew Watson, who led the study.

“The difference in ocean uptake we calculate amounts to 10% of global fossil fuel emissions.” – Climate News Network

As climates change, forests may not absorb more carbon as expected. But a new carbon budget could appeal to the oceans.

LONDON, 18 September 2020 – Two new studies could throw long-term climate forecasts into confusion. The planetary carbon budget – the all-important traffic of life’s first element between rocks, water, atmosphere and living things – that underpins planetary temperatures and maintains a stable climate needs a rethink.

A warming climate makes trees grow faster. The awkward finding is that  faster-growing trees die younger. Therefore they must surrender their carbon back to the atmosphere quicker.

So tomorrow’s forests may not be quite such reliable long-term banks of carbon pumped into the atmosphere as a consequence of profligate fossil fuel use by human economies.

The more reassuring news is that the ocean – that’s almost three fourths of the planet’s surface – may absorb and store a lot more atmospheric carbon than previous estimates suggest.

All calculations about the future rate of global heating, and the potential consequences of climate change, rest upon the carbon budget.

Forest doubts

This is the intricate accounting of the mass of carbon in continuous circulation from air to plant to animal and then to shell, skeleton and sediment, and the expected flow of carbon emissions from the combustion of fossil fuels stored hundreds of millions of years ago, and exhumed in the last two centuries.

To make sense of the factors at work, climate scientists have to make calculations about all the carbon stored in the permafrost, in the soils, in the forests, dissolved in the oceans, free in the atmosphere and being released from power station chimneys, vehicle exhausts and ploughed or scorched land.

But for decades, one component of the equation has been automatically accepted: more forests must mean more carbon absorbed, and better protected natural forests would store the most carbon, the most efficiently.

Now a new report in the journal Nature Communications introduces some doubt into this cornerstone of the carbon budget. In an already warming world, much more of the carbon stored in tomorrow’s forests might find its way back into the atmosphere.

Researchers looked at 200,000 tree ring records from 82 tree species from sites around the planet. They found what they describe as trade-offs that are near universal: faster-growing trees have shorter lives.

“There is likely to be a timelag before we see the worst of the potential loss of carbon stocks from increases in tree mortality”

This was true in cool climates and warm ones, and in all species. So the hope that natural vegetation will respond to warmer temperatures by absorbing even more carbon becomes insecure, especially if it means that the more vigorous growth means simply swifter death and decay.

“Our modeling suggests that there is likely to be a timelag before we see the worst of the potential loss of carbon stocks from increases in tree mortality,” said Roel Brienen of the University of Leeds in the UK, who led the research. “They estimate that global increases in tree death don’t kick in until after sites show accelerated growth.”

All such research is provisional: the findings gain currency only when supported by other teams using different approaches. So it has yet to be confirmed.

But recent studies have suggested that climate change has already begun to complicate calculations. Just in recent months, research teams have found that forest trees are growing shorter and dying younger; that higher temperatures may affect plant germination; and that forests already hit by drought may start surrendering carbon more swiftly than they absorb it. Planting more trees is not an alternative to reducing greenhouse gas emissions.

On the other hand, the carbon budget may still make sense: the oceans may be responding to ever-higher concentrations of carbon dioxide by absorbing more from the atmosphere, which also makes the oceans more acidic, which is not necessarily helpful.

Oceans’ effect

All such calculations are based on sea surface temperatures. Gases such as carbon dioxide and oxygen dissolve well in colder water, not so well in warm lagoons and tropical tides.

But a British group reports in the same journal that calculations so far may have been under-estimates. This is because, on balance, researchers have tended to ignore the small difference between the temperatures at the surface, and a few metres down, where the measurements of dissolved greenhouse gas were actually made.

A team from the University of Exeter worked from a global database to make new estimates of the oceans’ appetite for carbon between 1992 and 2018.

“We used satellite data to correct for these temperature differences, and when we do that, it makes a big difference – we get a substantially larger flux going into the ocean,” said Andrew Watson, who led the study.

“The difference in ocean uptake we calculate amounts to 10% of global fossil fuel emissions.” – 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

Hotter oceans harm seabed life survival prospects

Seabed life is tough: only the young can migrate. But climate change is taking many of them the wrong way.

LONDON, 14 September, 2020 – It can be hard being a junior part of seabed life – a young starfish, say, or an adolescent worm. Down in the ocean depths, the environment is conspiring against you.

Marine biologists have just identified – and explained – a climate change paradox: while most fish are migrating towards the poles as the world’s oceans warm, one part of a potentially valuable commercial fishery is heading in the wrong direction – and perhaps to extinction.

Why? Once again, the finger of suspicion points to global climate change, and its impact on ocean tides and currents.

Throughout this century, researchers have repeatedly confirmed a pattern of ocean warming – and acidification – driven by ever-rising ratios of carbon dioxide in the atmosphere; a pattern that could affect both established commercial fishing industries and ocean life as a whole.

Tropical fish have been shifting away from the equator; further north and south, pelagic (open-ocean) and demersal (seabed-dwelling) fish have been seeking more suitable grounds. Warmer seas can affect spawning patterns.

“As the seas continue to warm, spawning times will get ever earlier and the currents will sweep many of the next generation to oblivion”

But the ocean is a vast living space, and the speed at which it warms tends to vary with depth.

US researchers report in the journal Nature Climate Change that they worked through 60 years of data on 50 species of benthic invertebrates – creatures without backbones that dwell on the sea floor – to find that the populations of four-fifths of these had begun to disappear from the shelves and fishing grounds of the Georges Bank and the outer shelf that runs from New Jersey and east of the Delmarva Peninsula occupied by the states of Delaware, Maryland and Virginia.

More to the point, they identified the mechanism that had begun to limit life on the submarine sediments. Bottom-dwellers – shellfish, snails, starfish, worms and so on – can’t migrate: they are stuck where they are. But their larvae can, and at spawning time the infant shellfish are at the mercy of the ocean currents.

The waters of the north-east Atlantic coast are warming at three times the global average rate. Warming has affected the time at which benthic invertebrates spawn. Because the larvae appear earlier in spring and summer, they are swept away by currents they would not encounter in a cooler, more stable world.

And these currents, driven by river discharge and seasonal winds, tend to bring them south-west and inshore, where waters are warmer and the larvae are even less likely to survive.

Nowhere to go

Those adults that remain are stuck where they are: as the seas continue to warm, spawning times will get ever earlier and the currents will sweep many of the next generation to oblivion.

These bottom-dwelling denizens could survive, if they could colonise cooler waters. Instead they are condemned to a submarine version of what terrestrial biologists call the elevator to extinction: on land, hotter temperatures drive birds and butterflies and plants ever further uphill: in the end, nearer the summit, there’s nowhere to go.

The researchers, from Rutgers University in New Brunswick, call it the downwelling effect, and identify a paradox: as the area habitable by bottom-dwellers gets bigger, their ranges dwindle.

The finding so far is true only for the north-east Atlantic waters, and some species seem less affected. Scallops could flourish, because they spawn at a wider range of temperatures. But clams and mussels are adapted to low temperatures, and their ranges have warmed and contracted.

And, the scientists warn, as global heating reduces yields from traditional fisheries, the seafood industry is likely to rely increasingly on shellfish. But this industry, too, is vulnerable to ocean change. – Climate News Network

Seabed life is tough: only the young can migrate. But climate change is taking many of them the wrong way.

LONDON, 14 September, 2020 – It can be hard being a junior part of seabed life – a young starfish, say, or an adolescent worm. Down in the ocean depths, the environment is conspiring against you.

Marine biologists have just identified – and explained – a climate change paradox: while most fish are migrating towards the poles as the world’s oceans warm, one part of a potentially valuable commercial fishery is heading in the wrong direction – and perhaps to extinction.

Why? Once again, the finger of suspicion points to global climate change, and its impact on ocean tides and currents.

Throughout this century, researchers have repeatedly confirmed a pattern of ocean warming – and acidification – driven by ever-rising ratios of carbon dioxide in the atmosphere; a pattern that could affect both established commercial fishing industries and ocean life as a whole.

Tropical fish have been shifting away from the equator; further north and south, pelagic (open-ocean) and demersal (seabed-dwelling) fish have been seeking more suitable grounds. Warmer seas can affect spawning patterns.

“As the seas continue to warm, spawning times will get ever earlier and the currents will sweep many of the next generation to oblivion”

But the ocean is a vast living space, and the speed at which it warms tends to vary with depth.

US researchers report in the journal Nature Climate Change that they worked through 60 years of data on 50 species of benthic invertebrates – creatures without backbones that dwell on the sea floor – to find that the populations of four-fifths of these had begun to disappear from the shelves and fishing grounds of the Georges Bank and the outer shelf that runs from New Jersey and east of the Delmarva Peninsula occupied by the states of Delaware, Maryland and Virginia.

More to the point, they identified the mechanism that had begun to limit life on the submarine sediments. Bottom-dwellers – shellfish, snails, starfish, worms and so on – can’t migrate: they are stuck where they are. But their larvae can, and at spawning time the infant shellfish are at the mercy of the ocean currents.

The waters of the north-east Atlantic coast are warming at three times the global average rate. Warming has affected the time at which benthic invertebrates spawn. Because the larvae appear earlier in spring and summer, they are swept away by currents they would not encounter in a cooler, more stable world.

And these currents, driven by river discharge and seasonal winds, tend to bring them south-west and inshore, where waters are warmer and the larvae are even less likely to survive.

Nowhere to go

Those adults that remain are stuck where they are: as the seas continue to warm, spawning times will get ever earlier and the currents will sweep many of the next generation to oblivion.

These bottom-dwelling denizens could survive, if they could colonise cooler waters. Instead they are condemned to a submarine version of what terrestrial biologists call the elevator to extinction: on land, hotter temperatures drive birds and butterflies and plants ever further uphill: in the end, nearer the summit, there’s nowhere to go.

The researchers, from Rutgers University in New Brunswick, call it the downwelling effect, and identify a paradox: as the area habitable by bottom-dwellers gets bigger, their ranges dwindle.

The finding so far is true only for the north-east Atlantic waters, and some species seem less affected. Scallops could flourish, because they spawn at a wider range of temperatures. But clams and mussels are adapted to low temperatures, and their ranges have warmed and contracted.

And, the scientists warn, as global heating reduces yields from traditional fisheries, the seafood industry is likely to rely increasingly on shellfish. But this industry, too, is vulnerable to ocean change. – Climate News Network

Pandemic’s impacts are damaging climate research

Climate research is suffering permanent damage from some of the Covid-19 pandemic’s impacts, a UN report says.

LONDON, 9 September, 2020 − Whatever else the coronavirus onslaught is doing to humankind, some of the pandemic’s impacts are clear. It is making it harder for researchers to establish just what effect climate change is having on the planet.

A group of United Nations and other agencies is today launching a report, United in Science 2020, (webcast at 1600 hours New York time) which it calls “a high-level compilation of the latest climate science information”. It is being launched by the UN secretary-general, António Guterres, with a virtual link to his counterpart at the World Meteorological Organisation,  Petteri Taalas, in Geneva.

Much of what the report says will already be familiar, but its detailed finding that the pandemic is causing long-term damage to climate change monitoring is sobering.

Science advances by combining knowledge of the past with experience of the present and then combining them to forecast the probable future. That is how climate scientists have been able very recently to state that their earlier worst case scenario isn’t just an awful warning, but describes what is happening right now.

Several contenders have vied to be identified as the one who wrote: “You cannot manage what you cannot measure.” Which of them − if any − really did write that may not matter much. But it certainly matters for today’s researchers to know where the biosphere came from and where it is now if they are to have any idea where we shall all be in a few years.

Recalled to port

So it’s alarming that United in Science 2020, in its section on earth system observations, says: “The Covid-19 pandemic has produced significant impacts on the global observing systems, which in turn have affected the quality of forecasts and other weather, climate and ocean-related services.

“The reduction of aircraft-based observations by an average of 75% to 80% in March and April degraded the forecast skills of weather models. Since June, there has been only a slight recovery. Observations at manually-operated weather stations, especially in Africa and South America, have also been badly disrupted.”

In March this year, it says, nearly all oceanographic research vessels were recalled to home ports. Commercial ships have been unable to contribute vital ocean and weather observations, and ocean buoys and other systems could not be maintained.

Four “valuable” full-depth ocean surveys of variables such as carbon, temperature, salinity, and water alkalinity, completed only once every decade, have been cancelled. Surface carbon measurements from ships, which cast light on the evolution of greenhouse gases, also effectively stopped.

The impacts on climate change monitoring are long-term. They are likely to prevent or restrict measurement of glaciers and the thickness of permafrost, usually conducted at the end of the thawing period.

In an ominous warning the report notes that the overall disruption of observations will introduce gaps in the historical time series of Essential Climate Variables, vital for understanding what is happening to the planetary climate.

“The reduction of aircraft-based observations by an average of 75% to 80% in March and April degraded the forecast skills of weather models”

The report’s authors are also concerned about climate and water, where they expect the pandemic’s impacts to intensify existing problems. By 2050, they say, the number of people at risk of floods will increase from 1.2 billion now to 1.6 bn.

In the early to mid-2010s, 1.9 bn people, or 27% of the global population, lived in potential severely water-scarce areas. In 2050, this number will increase to between 2.7 and 3.2 bn people.

It is estimated that central Europe and the Caucasus have already reached peak water, and that the Tibetan Plateau region will do so between 2030 and 2050.

Runoff from snow cover, permafrost and glaciers in this region provides up to 45% of the total river flow, so a decrease would affect water availability for 1.7 bn people.

United in Science 2020 also says the world is a very long way from living up to its promises, with the targets of the Paris Agreement on climate change nowhere near being met.

The UN’s Emissions Gap Report 2019 compares “where we are likely to be and where we need to be” on cutting emissions of greenhouse gases (GHGs). The annual series of Gap Reports use gigatonnes (Gt) as units of measurement: one gigatonne is a billion metric tons.

Record emissions

Another frequent formula is GtCO2e, an abbreviation for “gigatonnes of equivalent carbon dioxide”. That’s a simplified way to put emissions of various GHGs on a common footing by expressing them in terms of the amount of carbon dioxide that would have the same global warming effect.

The 2019 Report says GHG emissions reached a record high of 55.3 GtCO2e in 2018. It continues: “There is no sign of GHG emissions peaking in the next few years; every year of postponed peaking means that deeper and faster cuts will be required.

“By 2030, emissions would need to be 25% and 55% lower than in 2018 to put the world on the least-cost pathway to limiting global warming to below 2 ̊C and 1.5°C respectively” [the two Paris Agreement targets].

The Gap in 2030 is estimated at 12-15 gigatonnes if the world is to limit global warming to below 2 °C. For the 1.5 °C goal, it is estimated at 29-32 Gt, roughly equivalent to the combined emissions of the world’s six largest emitters.

That’s an awful lot of GHGs which, as things stand, are going to be adding their heat to a torrid world a decade from now. − Climate News Network

Climate research is suffering permanent damage from some of the Covid-19 pandemic’s impacts, a UN report says.

LONDON, 9 September, 2020 − Whatever else the coronavirus onslaught is doing to humankind, some of the pandemic’s impacts are clear. It is making it harder for researchers to establish just what effect climate change is having on the planet.

A group of United Nations and other agencies is today launching a report, United in Science 2020, (webcast at 1600 hours New York time) which it calls “a high-level compilation of the latest climate science information”. It is being launched by the UN secretary-general, António Guterres, with a virtual link to his counterpart at the World Meteorological Organisation,  Petteri Taalas, in Geneva.

Much of what the report says will already be familiar, but its detailed finding that the pandemic is causing long-term damage to climate change monitoring is sobering.

Science advances by combining knowledge of the past with experience of the present and then combining them to forecast the probable future. That is how climate scientists have been able very recently to state that their earlier worst case scenario isn’t just an awful warning, but describes what is happening right now.

Several contenders have vied to be identified as the one who wrote: “You cannot manage what you cannot measure.” Which of them − if any − really did write that may not matter much. But it certainly matters for today’s researchers to know where the biosphere came from and where it is now if they are to have any idea where we shall all be in a few years.

Recalled to port

So it’s alarming that United in Science 2020, in its section on earth system observations, says: “The Covid-19 pandemic has produced significant impacts on the global observing systems, which in turn have affected the quality of forecasts and other weather, climate and ocean-related services.

“The reduction of aircraft-based observations by an average of 75% to 80% in March and April degraded the forecast skills of weather models. Since June, there has been only a slight recovery. Observations at manually-operated weather stations, especially in Africa and South America, have also been badly disrupted.”

In March this year, it says, nearly all oceanographic research vessels were recalled to home ports. Commercial ships have been unable to contribute vital ocean and weather observations, and ocean buoys and other systems could not be maintained.

Four “valuable” full-depth ocean surveys of variables such as carbon, temperature, salinity, and water alkalinity, completed only once every decade, have been cancelled. Surface carbon measurements from ships, which cast light on the evolution of greenhouse gases, also effectively stopped.

The impacts on climate change monitoring are long-term. They are likely to prevent or restrict measurement of glaciers and the thickness of permafrost, usually conducted at the end of the thawing period.

In an ominous warning the report notes that the overall disruption of observations will introduce gaps in the historical time series of Essential Climate Variables, vital for understanding what is happening to the planetary climate.

“The reduction of aircraft-based observations by an average of 75% to 80% in March and April degraded the forecast skills of weather models”

The report’s authors are also concerned about climate and water, where they expect the pandemic’s impacts to intensify existing problems. By 2050, they say, the number of people at risk of floods will increase from 1.2 billion now to 1.6 bn.

In the early to mid-2010s, 1.9 bn people, or 27% of the global population, lived in potential severely water-scarce areas. In 2050, this number will increase to between 2.7 and 3.2 bn people.

It is estimated that central Europe and the Caucasus have already reached peak water, and that the Tibetan Plateau region will do so between 2030 and 2050.

Runoff from snow cover, permafrost and glaciers in this region provides up to 45% of the total river flow, so a decrease would affect water availability for 1.7 bn people.

United in Science 2020 also says the world is a very long way from living up to its promises, with the targets of the Paris Agreement on climate change nowhere near being met.

The UN’s Emissions Gap Report 2019 compares “where we are likely to be and where we need to be” on cutting emissions of greenhouse gases (GHGs). The annual series of Gap Reports use gigatonnes (Gt) as units of measurement: one gigatonne is a billion metric tons.

Record emissions

Another frequent formula is GtCO2e, an abbreviation for “gigatonnes of equivalent carbon dioxide”. That’s a simplified way to put emissions of various GHGs on a common footing by expressing them in terms of the amount of carbon dioxide that would have the same global warming effect.

The 2019 Report says GHG emissions reached a record high of 55.3 GtCO2e in 2018. It continues: “There is no sign of GHG emissions peaking in the next few years; every year of postponed peaking means that deeper and faster cuts will be required.

“By 2030, emissions would need to be 25% and 55% lower than in 2018 to put the world on the least-cost pathway to limiting global warming to below 2 ̊C and 1.5°C respectively” [the two Paris Agreement targets].

The Gap in 2030 is estimated at 12-15 gigatonnes if the world is to limit global warming to below 2 °C. For the 1.5 °C goal, it is estimated at 29-32 Gt, roughly equivalent to the combined emissions of the world’s six largest emitters.

That’s an awful lot of GHGs which, as things stand, are going to be adding their heat to a torrid world a decade from now. − Climate News Network

Hotter oceans make the tropics expand polewards

The tropical climate zones are not just warmer, they now cover more of the planet. Blame it on steadily hotter oceans.

LONDON, 27 August, 2020 – The tropics are on the march and US and German scientists think they know why: hotter oceans have taken control.

The parched, arid fringes of the hot, moist conditions that nourish the equatorial forest band around the middle of the globe are moving, unevenly, further north and south in response to climate change.

And the role of the ocean is made even more dramatic in the southern hemisphere: because the ocean south of the equator is so much bigger than in the north, the southward shift of the parched zone is even more pronounced.

Across the globe, things don’t look good for places like California, which has already suffered some of its worst droughts and fires on record, and  Australia, where drought and fire if possible have been even worse.

In the past century or so, carbon dioxide levels in the atmosphere have risen from what was once a stable average of 285 parts per million to more than 400 ppm, and global average temperatures are now at least 1°C higher than they have been for most of human history.

“We demonstrate that the enhanced subtropical ocean warming is independent from the natural climate oscillations. This is a result of global warming”

And although the fastest and most dramatic changes in the world have been in the coldest zones – and particularly the Arctic – the tropics, too, have begun to feel the heat.

Researchers have observed tropical fish moving into cooler waters; they have warned that some tropical plant species may soon find temperatures too high for germination; they have mapped tropical cyclones hitting further north and south with time, and doing more damage; and they have seen evidence that tropical diseases could soon advance even into temperate Europe.

But although satellite observations have revealed that the tropical climate zone has expanded beyond the formal limits known as the Tropics of Capricorn and Cancer, and is doing so at somewhere between a quarter and half a degree of latitude each decade, no one has been able to work out why the shift is more pronounced in the southern half of the globe.

Now a new study in the Journal of Geophysical Research: Atmospheres offers an answer. The expansion of the tropics has been driven by ocean warming.

And if that expansion is more obvious in the southern hemisphere, it is because there is more sea to have more impact.

Clear link

Researchers analysed water temperature patterns in the great ocean gyres, those giant circular currents that take warm waters to the poles and return cold water to the equatorial regions.

They matched satellite readings from 1982 – the first year in the series of measurements – with data from 2018, and compared these to measurements of tropical zone expansion.

The connection was clear: excess heat that had been building up in the subtropical oceans ever since global warming began had driven both tropical edges and ocean gyres towards the poles.

That is, the shift in the tropics wasn’t just one of those slow pulses of expansion and retraction, of cyclic change, that happen in a complex world. And more precisely, the tropics were expanding more clearly in those places where the gyres moved poleward.

“We demonstrate that the enhanced subtropical ocean warming is independent from the natural climate oscillations,” said Hu Yang of the Alfred Wegener Institute in Bremerhaven, Germany, who led the research. “This is a result of global warming.” – Climate News Network

The tropical climate zones are not just warmer, they now cover more of the planet. Blame it on steadily hotter oceans.

LONDON, 27 August, 2020 – The tropics are on the march and US and German scientists think they know why: hotter oceans have taken control.

The parched, arid fringes of the hot, moist conditions that nourish the equatorial forest band around the middle of the globe are moving, unevenly, further north and south in response to climate change.

And the role of the ocean is made even more dramatic in the southern hemisphere: because the ocean south of the equator is so much bigger than in the north, the southward shift of the parched zone is even more pronounced.

Across the globe, things don’t look good for places like California, which has already suffered some of its worst droughts and fires on record, and  Australia, where drought and fire if possible have been even worse.

In the past century or so, carbon dioxide levels in the atmosphere have risen from what was once a stable average of 285 parts per million to more than 400 ppm, and global average temperatures are now at least 1°C higher than they have been for most of human history.

“We demonstrate that the enhanced subtropical ocean warming is independent from the natural climate oscillations. This is a result of global warming”

And although the fastest and most dramatic changes in the world have been in the coldest zones – and particularly the Arctic – the tropics, too, have begun to feel the heat.

Researchers have observed tropical fish moving into cooler waters; they have warned that some tropical plant species may soon find temperatures too high for germination; they have mapped tropical cyclones hitting further north and south with time, and doing more damage; and they have seen evidence that tropical diseases could soon advance even into temperate Europe.

But although satellite observations have revealed that the tropical climate zone has expanded beyond the formal limits known as the Tropics of Capricorn and Cancer, and is doing so at somewhere between a quarter and half a degree of latitude each decade, no one has been able to work out why the shift is more pronounced in the southern half of the globe.

Now a new study in the Journal of Geophysical Research: Atmospheres offers an answer. The expansion of the tropics has been driven by ocean warming.

And if that expansion is more obvious in the southern hemisphere, it is because there is more sea to have more impact.

Clear link

Researchers analysed water temperature patterns in the great ocean gyres, those giant circular currents that take warm waters to the poles and return cold water to the equatorial regions.

They matched satellite readings from 1982 – the first year in the series of measurements – with data from 2018, and compared these to measurements of tropical zone expansion.

The connection was clear: excess heat that had been building up in the subtropical oceans ever since global warming began had driven both tropical edges and ocean gyres towards the poles.

That is, the shift in the tropics wasn’t just one of those slow pulses of expansion and retraction, of cyclic change, that happen in a complex world. And more precisely, the tropics were expanding more clearly in those places where the gyres moved poleward.

“We demonstrate that the enhanced subtropical ocean warming is independent from the natural climate oscillations,” said Hu Yang of the Alfred Wegener Institute in Bremerhaven, Germany, who led the research. “This is a result of global warming.” – Climate News Network