Category Archives: Oceans

Climate change causes Canada’s oxygen loss

Scientists say climate change is causing oxygen loss in the cold waters of eastern Canada, imperilling the Greenland halibut and the Atlantic cod.

LONDON, 24 September, 2018 – Oceanographers have identified an act of slow suffocation, as oxygen loss grows near one of the world’s richest fishing grounds, and are linking the change to human-triggered global warming.

They have measured a dramatic drop in levels of dissolved oxygen deep in the Gulf of St Lawrence, in eastern Canada, and they link this increasing strangulation to shifts – connected to climate change driven by ever higher ratios of carbon dioxide in the atmosphere, as a consequence of the profligate burning of coal, oil and natural gas – in the Gulf Stream and the Labrador Current.

As carbon dioxide and other greenhouse gas levels have risen in the past 100 years, the Gulf Stream has shifted northward, and the Labrador Current has weakened. As a consequence, according to new research in Nature Climate Change, more warm, salty and oxygen-depleted water from the Gulf Stream is getting into one of the world’s great waterways.

Lower oxygen levels have already affected the Atlantic wolffish, the researchers say. And the change is a threat to the Atlantic cod, and the Greenland halibut: two of the world’s most prized commercial catches.

“The oxygen decline in this region was already reported, but what was not explored before was the underlying cause”

“Observations in the very inner Gulf of St Lawrence show a dramatic oxygen decline, which is reaching hypoxic conditions, meaning it can’t fully support marine life,” said Mariona Claret, of the University of Washington, who led the study.

“The oxygen decline in this region was already reported, but what was not explored before was the underlying cause.”

Researchers have warned for years that warmer waters mean lower levels of dissolved oxygen, and therefore ever greater risk of “dead zones” in the world’s oceans. There has been evidence that rates of oxygen depletion are higher than expected and direct evidence that fish may be voting with their fins, by migrating northwards as the oceans heat up.

Canadian fishery authorities have been measuring the salinity and temperature in the St Lawrence seaway since 1920, and oxygen levels since 1960. The latest study finds that the changes there have been more than twice the average change of 2% measured for the Atlantic and the oceans as a whole.

Current falters

An intricate, detailed computer simulation of the gulf and the seaway shows that the Labrador Current, which brings cold, oxygen-rich water southwards, has faltered, and the Gulf Stream – already warm and less oxygenated – has gained in ground.

The study also links shifts off coastal Canada to the bigger picture of an alarming decline in a marine monster called the Atlantic Meridional Overturning Circulation, which plays a powerful role in the climate of the North Atlantic.

The scientists speculate – their word – on the possibility that the lower oxygen levels in one watery corner of Canada “may ultimately influence the oxygen variability of the open North Atlantic.”

More alarmingly, they warn that their computer simulation may be delivering a very conservative picture, and that future oxygen declines in the Gulf may be “significantly larger.” – Climate News Network

Scientists say climate change is causing oxygen loss in the cold waters of eastern Canada, imperilling the Greenland halibut and the Atlantic cod.

LONDON, 24 September, 2018 – Oceanographers have identified an act of slow suffocation, as oxygen loss grows near one of the world’s richest fishing grounds, and are linking the change to human-triggered global warming.

They have measured a dramatic drop in levels of dissolved oxygen deep in the Gulf of St Lawrence, in eastern Canada, and they link this increasing strangulation to shifts – connected to climate change driven by ever higher ratios of carbon dioxide in the atmosphere, as a consequence of the profligate burning of coal, oil and natural gas – in the Gulf Stream and the Labrador Current.

As carbon dioxide and other greenhouse gas levels have risen in the past 100 years, the Gulf Stream has shifted northward, and the Labrador Current has weakened. As a consequence, according to new research in Nature Climate Change, more warm, salty and oxygen-depleted water from the Gulf Stream is getting into one of the world’s great waterways.

Lower oxygen levels have already affected the Atlantic wolffish, the researchers say. And the change is a threat to the Atlantic cod, and the Greenland halibut: two of the world’s most prized commercial catches.

“The oxygen decline in this region was already reported, but what was not explored before was the underlying cause”

“Observations in the very inner Gulf of St Lawrence show a dramatic oxygen decline, which is reaching hypoxic conditions, meaning it can’t fully support marine life,” said Mariona Claret, of the University of Washington, who led the study.

“The oxygen decline in this region was already reported, but what was not explored before was the underlying cause.”

Researchers have warned for years that warmer waters mean lower levels of dissolved oxygen, and therefore ever greater risk of “dead zones” in the world’s oceans. There has been evidence that rates of oxygen depletion are higher than expected and direct evidence that fish may be voting with their fins, by migrating northwards as the oceans heat up.

Canadian fishery authorities have been measuring the salinity and temperature in the St Lawrence seaway since 1920, and oxygen levels since 1960. The latest study finds that the changes there have been more than twice the average change of 2% measured for the Atlantic and the oceans as a whole.

Current falters

An intricate, detailed computer simulation of the gulf and the seaway shows that the Labrador Current, which brings cold, oxygen-rich water southwards, has faltered, and the Gulf Stream – already warm and less oxygenated – has gained in ground.

The study also links shifts off coastal Canada to the bigger picture of an alarming decline in a marine monster called the Atlantic Meridional Overturning Circulation, which plays a powerful role in the climate of the North Atlantic.

The scientists speculate – their word – on the possibility that the lower oxygen levels in one watery corner of Canada “may ultimately influence the oxygen variability of the open North Atlantic.”

More alarmingly, they warn that their computer simulation may be delivering a very conservative picture, and that future oxygen declines in the Gulf may be “significantly larger.” – Climate News Network

Tax havens threaten oceans and rainforests

Most of the foreign money funding ocean plunder and the felling of the Amazon forest comes through tax havens, researchers say.

LONDON, 14 August, 2018 – Tax havens have provided more than two-thirds of the foreign capital known to be linked to Amazon deforestation and pirate fishing, a new study says.

The researchers say 70% of known vessels involved in illegal, unreported and unregulated (IUU) fishing are or have been flagged under a tax haven jurisdiction. On average, they report, 68% of all investigated foreign capital (US$18.4bn of a total $26.9bn) which went to sectors associated with Amazon  deforestation between 2000 and 2011 was transferred through tax havens.

The report is the work of a team of researchers from the Stockholm Resilience Centre (SRC) and the Global Economic Dynamics and the Biosphere programme (GEDB), who say it is the first study to show how tax havens are linked to economic sectors with the potential to cause serious global environmental damage.

They say the release of the Paradise Papers and Panama Papers exposed how multinationals, politicians and the rich use offshore tax havens to conceal their wealth and money flows, and to reduce their exposure to tax. Accepting that the term “tax haven” is contested, their report uses a definition proposed in a report prepared for the US Congress.

The study’s lead author, Victor Galaz, deputy director of the SRC, says: “Our analysis shows that the use of tax havens is not only a socio-political and economic challenge, but also an environmental one. While the use of tax haven jurisdictions is not illegal in itself, financial secrecy hampers the ability to analyse how financial flows affect economic activities on the ground, and their environmental impacts.”

The study, published in the journal Nature Ecology and Evolution, is part of an on-going research project, Earth System Finance: New perspectives on financial markets and sustainability, led by GEDB and the Stockholm Resilience Centre in collaboration with Future Earth.

Systematic approach

The researchers say most previous analyses of the environmental impacts of tax havens are the work of investigative journalists focusing on a few locations. The new study, in contrast, takes a more systematic approach to analyse how the havens influence the sustainability of the ocean and the Amazon rainforest, two examples of the global environmental commons.

The Amazon forest is critical for stabilising the Earth’s climate system, and the oceans provide protein and income for millions of people worldwide, particularly in low-income food-deficit countries.

“The absence of a more systemic view is not surprising considering the chronic lack of data resulting from the financial opaqueness created by the use of these jurisdictions,” says co-author Beatrice Crona, GEDB’s executive director.

The study says lack of transparency hides how tax havens are linked to the degradation of environmental commons that are crucial for both people and planet at global scales.

“The use of tax havens is not only a socio-political and economic challenge, but also an environmental one”

It includes the first calculation of the foreign capital that flows into the beef and soya sectors operating in the Brazilian Amazon, both linked to deforestation.

The Cayman Islands proved to be the largest governmental source of transfers for foreign capital to both sectors. Well-known as a tax haven, the Islands provide three benefits to investors: legal efficiency, tax minimisation, and secrecy.

The study also includes a systematic analysis of tax havens’ role in global IUU fishing. With 70% of the vessels found to carry out or support IUU fishing, and for which flag information is available, flagged under a tax haven jurisdiction now or in the past, Belize and Panama are frequently mentioned.

Many of these tax havens are also so-called flags of convenience states, countries with limited monitoring and enforcement capacity that do not penalise vessels sailing under their flag even if they are identified as operating in violation of international law.

Dual identities

This combination of tax havens and flags of convenience allows companies to operate fishing vessels with dual identities, one used for legal and the other for illegal fishing.

“The global nature of fisheries value chains, complex ownership structures and limited governance capacities of many coastal nations, make the sector susceptible to the use of tax havens,” says co-author Henrik Österblom, SRC  deputy science director.

Among issues which the researchers suggest should be central to future research and to the governance of tax havens is the loss of tax revenue the havens cause. This, they argue, should be seen as an indirect subsidy to economic activities which damage the global commons, and organisations like UN Environment should assess the environmental costs involved.

And they argue that the international community should view tax evasion and aggressive tax planning as not only a socio-political problem, but also an environmental one. Putting tax havens on the global sustainability agenda, they say, is key to protecting the environment and achieving the UN Sustainable Development Goals. – Climate News Network

Most of the foreign money funding ocean plunder and the felling of the Amazon forest comes through tax havens, researchers say.

LONDON, 14 August, 2018 – Tax havens have provided more than two-thirds of the foreign capital known to be linked to Amazon deforestation and pirate fishing, a new study says.

The researchers say 70% of known vessels involved in illegal, unreported and unregulated (IUU) fishing are or have been flagged under a tax haven jurisdiction. On average, they report, 68% of all investigated foreign capital (US$18.4bn of a total $26.9bn) which went to sectors associated with Amazon  deforestation between 2000 and 2011 was transferred through tax havens.

The report is the work of a team of researchers from the Stockholm Resilience Centre (SRC) and the Global Economic Dynamics and the Biosphere programme (GEDB), who say it is the first study to show how tax havens are linked to economic sectors with the potential to cause serious global environmental damage.

They say the release of the Paradise Papers and Panama Papers exposed how multinationals, politicians and the rich use offshore tax havens to conceal their wealth and money flows, and to reduce their exposure to tax. Accepting that the term “tax haven” is contested, their report uses a definition proposed in a report prepared for the US Congress.

The study’s lead author, Victor Galaz, deputy director of the SRC, says: “Our analysis shows that the use of tax havens is not only a socio-political and economic challenge, but also an environmental one. While the use of tax haven jurisdictions is not illegal in itself, financial secrecy hampers the ability to analyse how financial flows affect economic activities on the ground, and their environmental impacts.”

The study, published in the journal Nature Ecology and Evolution, is part of an on-going research project, Earth System Finance: New perspectives on financial markets and sustainability, led by GEDB and the Stockholm Resilience Centre in collaboration with Future Earth.

Systematic approach

The researchers say most previous analyses of the environmental impacts of tax havens are the work of investigative journalists focusing on a few locations. The new study, in contrast, takes a more systematic approach to analyse how the havens influence the sustainability of the ocean and the Amazon rainforest, two examples of the global environmental commons.

The Amazon forest is critical for stabilising the Earth’s climate system, and the oceans provide protein and income for millions of people worldwide, particularly in low-income food-deficit countries.

“The absence of a more systemic view is not surprising considering the chronic lack of data resulting from the financial opaqueness created by the use of these jurisdictions,” says co-author Beatrice Crona, GEDB’s executive director.

The study says lack of transparency hides how tax havens are linked to the degradation of environmental commons that are crucial for both people and planet at global scales.

“The use of tax havens is not only a socio-political and economic challenge, but also an environmental one”

It includes the first calculation of the foreign capital that flows into the beef and soya sectors operating in the Brazilian Amazon, both linked to deforestation.

The Cayman Islands proved to be the largest governmental source of transfers for foreign capital to both sectors. Well-known as a tax haven, the Islands provide three benefits to investors: legal efficiency, tax minimisation, and secrecy.

The study also includes a systematic analysis of tax havens’ role in global IUU fishing. With 70% of the vessels found to carry out or support IUU fishing, and for which flag information is available, flagged under a tax haven jurisdiction now or in the past, Belize and Panama are frequently mentioned.

Many of these tax havens are also so-called flags of convenience states, countries with limited monitoring and enforcement capacity that do not penalise vessels sailing under their flag even if they are identified as operating in violation of international law.

Dual identities

This combination of tax havens and flags of convenience allows companies to operate fishing vessels with dual identities, one used for legal and the other for illegal fishing.

“The global nature of fisheries value chains, complex ownership structures and limited governance capacities of many coastal nations, make the sector susceptible to the use of tax havens,” says co-author Henrik Österblom, SRC  deputy science director.

Among issues which the researchers suggest should be central to future research and to the governance of tax havens is the loss of tax revenue the havens cause. This, they argue, should be seen as an indirect subsidy to economic activities which damage the global commons, and organisations like UN Environment should assess the environmental costs involved.

And they argue that the international community should view tax evasion and aggressive tax planning as not only a socio-political problem, but also an environmental one. Putting tax havens on the global sustainability agenda, they say, is key to protecting the environment and achieving the UN Sustainable Development Goals. – Climate News Network

Human activity leaves diminished oceans

Humankind has already disturbed or degraded six-sevenths of the blue planet, with diminished oceans the result. And that is before the impact of climate change.

LONDON, 3 August, 2018 – Humans huddle on a small part of the Earth’s surface, but our activity on the rest will leave our descendants only diminished oceans. Thanks to us, the wilderness of the world’s wide seas has shrunk drastically.

Earth is a waterworld: 70% of it is swept by ocean. And 87% of this waterworld has been to some degree fouled, polluted, poisoned or impoverished by the actions of one almost entirely terrestrial mammal. That is, according to a new survey, only 13% of the high seas can now be considered true wilderness.

Terrestrial life is smeared thinly. It is concentrated almost entirely in an altitude bounded by tree roots and canopy. But all the ocean is habitable, from the tidal shallows to the abyssal plain. It is home to the greatest mountain chain on the planet and to the deepest chasms, and in all it makes up 99% of the living space on Earth.

Researchers who looked at 16 different kinds of watery realm and tested them for 15 different kinds of human impact – among them commercial shipping, sediment and fertiliser run-off, and overfishing – report in the journal Current Biology that humans had left their mark almost everywhere.

“We were astonished by just how little marine wilderness remains,” said Kendall Jones, a researcher at the University of Queensland in Australia, and also of the Wildlife Conservation Society.

Huge extent

“The ocean is immense, covering over 70% of our planet, but we’ve managed to significantly impact almost all of this vast ecosystem.”

The surviving watery wilderness is estimated at an area of 54 million square kilometres. Although this is seemingly an enormous tract – think of the land areas of Russia, China, Canada, the US and Australia rolled up together – it is still less than a seventh part of the sea surface.

Most of this “untouched” ocean is concentrated in the Arctic, the Antarctic, and around the more remote Pacific islands. Hardly any marine wilderness survives along the continental coastlines.

The study comes only weeks after a survey of land conservation areas – once again, led by researchers from the University of Queensland and the Wildlife Conservation Society – found that even those stretches of mountain, savannah, forest and wetland formally recognized by governments as nature reserves or conservation zones were in many cases significantly disturbed or degraded by human intrusion.

The plight of the high seas has been disturbing marine scientists and oceanographers for some time. They have repeatedly warned that human-driven climate change is affecting ocean temperatures and compromising the health of the ecosystems on which, for instance, commercial fisheries depend.

“Pristine wilderness areas hold massive levels of biodiversity and endemic species and are some of the last places on earth where big populations of apex predators are still found”

Human actions have created “dead zones” and great tracts of toxic algal growths fed by nutrients from the land. Plastic waste has been found almost everywhere, and changes in water chemistry threaten many species at all depths.

But the Queensland study looks only at those measurable human impacts that are not connected with climate change: the implicit message is that acidification, sea level rise, and ocean temperature increase, all of them driven by profligate human combustion of fossil fuels, will ultimately affect even those areas of ocean defined as surviving wilderness.

Research of this nature is inevitably a matter of meticulous accounting: scientists comb through huge numbers of studies, and identify the data on which they can rely, and then find ways to test their hypothesis. This involved, for instance, checking the range and distribution of more than 21,000 marine species, and separately considering submarine kelp forests, coastal reefs, warm and temperate zones, the deep ocean and the polar waters.

Little protection

The researchers found that more than 8% of the wilderness was in the warm Indo-Pacific and that only 5% of the remaining marine wilderness enjoyed any formal governmental or international protection.

“Pristine wilderness areas hold massive levels of biodiversity and endemic species and are some of the last places on earth where big populations of apex predators are still found,” Kendall Jones said.

“This means the vast majority of marine wilderness could be lost at any time, as improvements in technology allow us to fish deeper and ship farther than ever before.

“Thanks to a warming climate, even some places that were once safe due to year-round ice cover can now be fished.” – Climate News Network

Humankind has already disturbed or degraded six-sevenths of the blue planet, with diminished oceans the result. And that is before the impact of climate change.

LONDON, 3 August, 2018 – Humans huddle on a small part of the Earth’s surface, but our activity on the rest will leave our descendants only diminished oceans. Thanks to us, the wilderness of the world’s wide seas has shrunk drastically.

Earth is a waterworld: 70% of it is swept by ocean. And 87% of this waterworld has been to some degree fouled, polluted, poisoned or impoverished by the actions of one almost entirely terrestrial mammal. That is, according to a new survey, only 13% of the high seas can now be considered true wilderness.

Terrestrial life is smeared thinly. It is concentrated almost entirely in an altitude bounded by tree roots and canopy. But all the ocean is habitable, from the tidal shallows to the abyssal plain. It is home to the greatest mountain chain on the planet and to the deepest chasms, and in all it makes up 99% of the living space on Earth.

Researchers who looked at 16 different kinds of watery realm and tested them for 15 different kinds of human impact – among them commercial shipping, sediment and fertiliser run-off, and overfishing – report in the journal Current Biology that humans had left their mark almost everywhere.

“We were astonished by just how little marine wilderness remains,” said Kendall Jones, a researcher at the University of Queensland in Australia, and also of the Wildlife Conservation Society.

Huge extent

“The ocean is immense, covering over 70% of our planet, but we’ve managed to significantly impact almost all of this vast ecosystem.”

The surviving watery wilderness is estimated at an area of 54 million square kilometres. Although this is seemingly an enormous tract – think of the land areas of Russia, China, Canada, the US and Australia rolled up together – it is still less than a seventh part of the sea surface.

Most of this “untouched” ocean is concentrated in the Arctic, the Antarctic, and around the more remote Pacific islands. Hardly any marine wilderness survives along the continental coastlines.

The study comes only weeks after a survey of land conservation areas – once again, led by researchers from the University of Queensland and the Wildlife Conservation Society – found that even those stretches of mountain, savannah, forest and wetland formally recognized by governments as nature reserves or conservation zones were in many cases significantly disturbed or degraded by human intrusion.

The plight of the high seas has been disturbing marine scientists and oceanographers for some time. They have repeatedly warned that human-driven climate change is affecting ocean temperatures and compromising the health of the ecosystems on which, for instance, commercial fisheries depend.

“Pristine wilderness areas hold massive levels of biodiversity and endemic species and are some of the last places on earth where big populations of apex predators are still found”

Human actions have created “dead zones” and great tracts of toxic algal growths fed by nutrients from the land. Plastic waste has been found almost everywhere, and changes in water chemistry threaten many species at all depths.

But the Queensland study looks only at those measurable human impacts that are not connected with climate change: the implicit message is that acidification, sea level rise, and ocean temperature increase, all of them driven by profligate human combustion of fossil fuels, will ultimately affect even those areas of ocean defined as surviving wilderness.

Research of this nature is inevitably a matter of meticulous accounting: scientists comb through huge numbers of studies, and identify the data on which they can rely, and then find ways to test their hypothesis. This involved, for instance, checking the range and distribution of more than 21,000 marine species, and separately considering submarine kelp forests, coastal reefs, warm and temperate zones, the deep ocean and the polar waters.

Little protection

The researchers found that more than 8% of the wilderness was in the warm Indo-Pacific and that only 5% of the remaining marine wilderness enjoyed any formal governmental or international protection.

“Pristine wilderness areas hold massive levels of biodiversity and endemic species and are some of the last places on earth where big populations of apex predators are still found,” Kendall Jones said.

“This means the vast majority of marine wilderness could be lost at any time, as improvements in technology allow us to fish deeper and ship farther than ever before.

“Thanks to a warming climate, even some places that were once safe due to year-round ice cover can now be fished.” – Climate News Network

Fish can’t smell well in more acidic seas

If you can’t smell food, you’re in trouble, and it’s worse if you can’t scent danger. More acidic seas could affect fishes’ ability to smell.

LONDON, 23 July, 2018 – More acidic seas mean greater dangers for fish. Sea bass tested in oceans with the greater levels of dissolved carbon dioxide expected at the end of the century had their sense of smell dramatically reduced by the change.

Since fish depend on smell to forage for food, avoid predators, recognise each other and identify spawning grounds, the loss of smell could mean a more dangerous world.

British and Portuguese scientists report in the journal Nature Climate Change that they used a mix of physiological and behavioural studies to work out how a valuable commercial species – Dicentrarchus labrax, also known as the European bass or loup de mer – responded to higher levels of dissolved carbon dioxide (CO2) in ocean waters.

Oceanic CO2 has risen by 43% since the start of the Industrial Revolution, when humans began burning fossil fuels at ever-increasing rates, to discharge greenhouse gases into the atmosphere, and thus into the seas. By 2100, current levels of this dissolved gas will have more than doubled.

And the researchers found that to detect a scent, under end-of-century conditions, juvenile bass had to be 42% nearer the source.

“Having to cope with two different problems caused by CO2, rather than just one, may reduce their ability to adapt or how long this will take”

“First we compared the behaviour of juvenile sea bass at CO2 levels typical of today’s ocean conditions, and those predicted for the end of the century,” said Cosima Porteous of the University of Exeter, UK, who led the research.

“Sea bass in acidic waters swam less and were less likely to respond when they encountered the smell of a predator. These fish were also more likely to ‘freeze’, indicating anxiety.”

The study confirms that economically important species will be affected by changes in ocean water chemistry: as waters warm, fish can migrate to cooler climates, but the impact of acidification will be much the same across the entire planet.

Researchers warned years ago that shifts in what chemists call the pH value of the oceans could seriously affect the citizens of the deep. Carbon dioxide has been implicated in at least one long-ago distant mass extinction event. Increasing acidification threatens corals and other species that employ carbonates. It has been found to alter behaviour or present a hazard to sharks, submarine snails and shrimps, and other species such as sea urchins and rockfish.

Commercial significance

The new study is hailed as the first to test the olfactory responses of a commercially important species. Although only sea bass were tested, mechanisms of smell in fish are thought to be the same across a wide range of species.

“Their ability to detect and respond to some odours associated with food and threatening situations was more strongly affected than for other odours. We think this is explained by acidified water affecting how odorant molecules bind to olfactory receptors in the fish’s nose, reducing how well they can distinguish these important stimuli,” said Dr Porteous.

And her colleague, Rod Wilson from Exeter, said: “Our intriguing results show that CO2 impacts the nose of the fish directly. This will be in addition to the impact of CO2 on their central nervous system function suggested by others previously, which proposed an impaired processing of information in the brain itself.

“It is not yet known how rapidly fish will be able to overcome these problems as CO2 rises in the future. However, having to cope with two different problems caused by CO2, rather than just one, may reduce their ability to adapt or how long this will take.” – Climate News Network

If you can’t smell food, you’re in trouble, and it’s worse if you can’t scent danger. More acidic seas could affect fishes’ ability to smell.

LONDON, 23 July, 2018 – More acidic seas mean greater dangers for fish. Sea bass tested in oceans with the greater levels of dissolved carbon dioxide expected at the end of the century had their sense of smell dramatically reduced by the change.

Since fish depend on smell to forage for food, avoid predators, recognise each other and identify spawning grounds, the loss of smell could mean a more dangerous world.

British and Portuguese scientists report in the journal Nature Climate Change that they used a mix of physiological and behavioural studies to work out how a valuable commercial species – Dicentrarchus labrax, also known as the European bass or loup de mer – responded to higher levels of dissolved carbon dioxide (CO2) in ocean waters.

Oceanic CO2 has risen by 43% since the start of the Industrial Revolution, when humans began burning fossil fuels at ever-increasing rates, to discharge greenhouse gases into the atmosphere, and thus into the seas. By 2100, current levels of this dissolved gas will have more than doubled.

And the researchers found that to detect a scent, under end-of-century conditions, juvenile bass had to be 42% nearer the source.

“Having to cope with two different problems caused by CO2, rather than just one, may reduce their ability to adapt or how long this will take”

“First we compared the behaviour of juvenile sea bass at CO2 levels typical of today’s ocean conditions, and those predicted for the end of the century,” said Cosima Porteous of the University of Exeter, UK, who led the research.

“Sea bass in acidic waters swam less and were less likely to respond when they encountered the smell of a predator. These fish were also more likely to ‘freeze’, indicating anxiety.”

The study confirms that economically important species will be affected by changes in ocean water chemistry: as waters warm, fish can migrate to cooler climates, but the impact of acidification will be much the same across the entire planet.

Researchers warned years ago that shifts in what chemists call the pH value of the oceans could seriously affect the citizens of the deep. Carbon dioxide has been implicated in at least one long-ago distant mass extinction event. Increasing acidification threatens corals and other species that employ carbonates. It has been found to alter behaviour or present a hazard to sharks, submarine snails and shrimps, and other species such as sea urchins and rockfish.

Commercial significance

The new study is hailed as the first to test the olfactory responses of a commercially important species. Although only sea bass were tested, mechanisms of smell in fish are thought to be the same across a wide range of species.

“Their ability to detect and respond to some odours associated with food and threatening situations was more strongly affected than for other odours. We think this is explained by acidified water affecting how odorant molecules bind to olfactory receptors in the fish’s nose, reducing how well they can distinguish these important stimuli,” said Dr Porteous.

And her colleague, Rod Wilson from Exeter, said: “Our intriguing results show that CO2 impacts the nose of the fish directly. This will be in addition to the impact of CO2 on their central nervous system function suggested by others previously, which proposed an impaired processing of information in the brain itself.

“It is not yet known how rapidly fish will be able to overcome these problems as CO2 rises in the future. However, having to cope with two different problems caused by CO2, rather than just one, may reduce their ability to adapt or how long this will take.” – Climate News Network

Nature may explain North Atlantic circulation

Ocean circulation distributes the planet’s heat. If the North Atlantic circulation slows, is it because of global warming, or a natural cycle?

LONDON, 26 July, 2018 – The world can breathe again. Europe can relax: the glaciers will not return. The North Atlantic circulation may resume its former pace and the Gulf Stream slowdown could be coming to an end.

But that may not be entirely good news. Global warming could also be about to accelerate, according to new research into one of oceanography’s most enigmatic phenomena, the North Atlantic Meridional Overturning Circulation.

New studies of all the data so far by an ocean scientist and a mathematician say that what affects North Atlantic circulation may not be driven by man-made climate change. The ocean may be responding to a very long-term natural climate cycle.

At the heart of the puzzle is a simple fact. The flow of warm water from the tropical Atlantic right up to the coast of northern Norway has a dramatic impact on western Europe’s climate. This means that the United Kingdom, France, and other nations are conspicuously warmer than they might be if latitude was the only factor.

“We do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic”

A former UK chief scientist once calculated that the Gulf Stream contributed 27,000 times the warmth generated by all the UK’s power stations. But theorists argued that as the Arctic region warmed, the rate of flow could diminish, and paradoxically throw Europe into a new little Ice Age. A 2004 Hollywood disaster movie called The Day After Tomorrow followed this logic, with Britain frozen and glaciers cascading south into the US.

In fact, no such calamitous and sudden return of the intense and lethal cold could happen, but researchers have since then consistently observed a pattern of slowing in the North Atlantic circulation, linked such slowdowns to global warming
driven by profligate use of fossil fuels that enrich the levels of greenhouse gases in the atmosphere, and repeatedly warned that the consequences could be costly or even devastating.

But a new study of the data available exposes other possibilities. In the first place, climate scientists have direct measurements of the circulation strength only from 2004, and the decline measured since then has been 10 times more than anyone expected. Perhaps the slowdown could be just part of a regular, rhythmic cycle that happens independently of anything humans have done to trigger global warming, researchers say in the journal Nature.

“Many have focused on the fact that it’s declining very rapidly, and that if the trend continues it will go past a tipping point, bringing a catastrophe such as an ice age,” said Ka-Kit Tung, a mathematician at the University of Washington in the US.

Already over

“It turns out that none of that is going to happen in the near future. The fast response may instead be part of a natural cycle and there are signs that the decline is already ending.”

The Atlantic Meridional Overturning Circulation takes warm surface water northward. The dense salty water sinks into the Labrador and Nordic Seas and returns at depth all the way to the Southern Ocean, to rise again. The puzzle is what happens next.

As the current sinks in the far north, it carries heat away from the surface. But the same transport of heat causes the northern glaciers to recede, and melt, diluting the saline water and making it less likely to sink. So the circulation slows.

The reasoning that follows is that, in a slow phase, the North Atlantic becomes cooler, the ice melt slows, the fresh meltwater sources begin to dry up and the heavier, saltier water plunges more urgently, and the whole circulation speeds up again.

Disagreement

And if this happens in a natural cycle – and not all climate scientists and oceanographers will agree – it is one that lasts for many decades: 60 to 70 years. But oceanographers don’t have the more than 60 to 70 years of measurements needed to confirm this pattern.

“We have about one cycle of observations at depth, so we do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic,” said Professor Tung.

“The good news is that the indicators show that this slowdown of the Atlantic overturning circulation is ending, and so we shouldn’t be alarmed that this current will collapse any time soon.

“The bad news is that surface temperatures are likely to start rising more quickly in the coming decades.” – Climate News Network

Ocean circulation distributes the planet’s heat. If the North Atlantic circulation slows, is it because of global warming, or a natural cycle?

LONDON, 26 July, 2018 – The world can breathe again. Europe can relax: the glaciers will not return. The North Atlantic circulation may resume its former pace and the Gulf Stream slowdown could be coming to an end.

But that may not be entirely good news. Global warming could also be about to accelerate, according to new research into one of oceanography’s most enigmatic phenomena, the North Atlantic Meridional Overturning Circulation.

New studies of all the data so far by an ocean scientist and a mathematician say that what affects North Atlantic circulation may not be driven by man-made climate change. The ocean may be responding to a very long-term natural climate cycle.

At the heart of the puzzle is a simple fact. The flow of warm water from the tropical Atlantic right up to the coast of northern Norway has a dramatic impact on western Europe’s climate. This means that the United Kingdom, France, and other nations are conspicuously warmer than they might be if latitude was the only factor.

“We do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic”

A former UK chief scientist once calculated that the Gulf Stream contributed 27,000 times the warmth generated by all the UK’s power stations. But theorists argued that as the Arctic region warmed, the rate of flow could diminish, and paradoxically throw Europe into a new little Ice Age. A 2004 Hollywood disaster movie called The Day After Tomorrow followed this logic, with Britain frozen and glaciers cascading south into the US.

In fact, no such calamitous and sudden return of the intense and lethal cold could happen, but researchers have since then consistently observed a pattern of slowing in the North Atlantic circulation, linked such slowdowns to global warming
driven by profligate use of fossil fuels that enrich the levels of greenhouse gases in the atmosphere, and repeatedly warned that the consequences could be costly or even devastating.

But a new study of the data available exposes other possibilities. In the first place, climate scientists have direct measurements of the circulation strength only from 2004, and the decline measured since then has been 10 times more than anyone expected. Perhaps the slowdown could be just part of a regular, rhythmic cycle that happens independently of anything humans have done to trigger global warming, researchers say in the journal Nature.

“Many have focused on the fact that it’s declining very rapidly, and that if the trend continues it will go past a tipping point, bringing a catastrophe such as an ice age,” said Ka-Kit Tung, a mathematician at the University of Washington in the US.

Already over

“It turns out that none of that is going to happen in the near future. The fast response may instead be part of a natural cycle and there are signs that the decline is already ending.”

The Atlantic Meridional Overturning Circulation takes warm surface water northward. The dense salty water sinks into the Labrador and Nordic Seas and returns at depth all the way to the Southern Ocean, to rise again. The puzzle is what happens next.

As the current sinks in the far north, it carries heat away from the surface. But the same transport of heat causes the northern glaciers to recede, and melt, diluting the saline water and making it less likely to sink. So the circulation slows.

The reasoning that follows is that, in a slow phase, the North Atlantic becomes cooler, the ice melt slows, the fresh meltwater sources begin to dry up and the heavier, saltier water plunges more urgently, and the whole circulation speeds up again.

Disagreement

And if this happens in a natural cycle – and not all climate scientists and oceanographers will agree – it is one that lasts for many decades: 60 to 70 years. But oceanographers don’t have the more than 60 to 70 years of measurements needed to confirm this pattern.

“We have about one cycle of observations at depth, so we do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic,” said Professor Tung.

“The good news is that the indicators show that this slowdown of the Atlantic overturning circulation is ending, and so we shouldn’t be alarmed that this current will collapse any time soon.

“The bad news is that surface temperatures are likely to start rising more quickly in the coming decades.” – Climate News Network

Alien seaweed arrives in Antarctica

For more than a century, scientists believed that only humans could cross the hostile oceans to reach Antarctica. Some strands of alien seaweed tell another story.

LONDON, 19 July, 2018 – A foreign invader, a species of alien seaweed, has managed to cross the oceans to reach the frozen Antarctic shores. So scientists may have to give up a cherished belief: that Antarctica is inviolate.

For a century, researchers have assumed that the mix of ocean currents, distance and temperature have kept the Great White Continent shielded from invasion by Pacific or Atlantic flotsam.

But the discovery of strands of kelp on an Antarctic beach – seaweed that may have drifted for considerable periods and a distance of 20,000 kms before becoming stranded far from home – brings an end to that belief. And the discovery suggests that global warming could bring serious changes to Antarctic ecosystems.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected”

“This finding shows us that living plants and animals can reach Antarctica across the ocean, with temperate and sub-Antarctic marine species probably bombarding Antarctic coastlines all the time,” said Ceridwen Fraser, of the Australian National University.

“We always thought Antarctic plants and animals were distinct because they were isolated, but this research now suggests these differences are almost entirely due to environmental extremes, not isolation.”

Dr Fraser and her colleagues report in the journal Nature Climate Change that strands of southern bull kelp, Durvillaea antarctica, found by a Chilean scientist, must have floated 20,000 km from the Kerguelen Islands and South Georgia. The kelp was encrusted with barnacles, evidence of a long time adrift.

In fact, researchers believe, it may be evidence of the longest episode of “biological rafting” ever confirmed. The word raft is significant: such floating platforms could provide shelter and transport for other biological invaders.

Plastic next?

Until now, the assumption has been that the pattern of surface currents and westerly winds tends to drive drifting material northwards from Antarctica. The discovery suggests that if kelp can get there, so can floating driftwood, or plastic debris, or any other unwelcome visitor.

The researchers think large waves driven by Southern Ocean storms may have steered the kelp rafts over what had been considered a natural ocean barrier. Global warming has begun to change conditions in Antarctica, and the continent – considered the last great tract of terrain unmarked by human colonisation – could become increasingly vulnerable to change.

“This is an unequivocal demonstration that marine species from the north can reach Antarctica. To get there the kelp had to pass through barriers created by polar winds and currents that were, until now, thought to be impenetrable,” Dr Fraser said.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected.” – Climate News Network

For more than a century, scientists believed that only humans could cross the hostile oceans to reach Antarctica. Some strands of alien seaweed tell another story.

LONDON, 19 July, 2018 – A foreign invader, a species of alien seaweed, has managed to cross the oceans to reach the frozen Antarctic shores. So scientists may have to give up a cherished belief: that Antarctica is inviolate.

For a century, researchers have assumed that the mix of ocean currents, distance and temperature have kept the Great White Continent shielded from invasion by Pacific or Atlantic flotsam.

But the discovery of strands of kelp on an Antarctic beach – seaweed that may have drifted for considerable periods and a distance of 20,000 kms before becoming stranded far from home – brings an end to that belief. And the discovery suggests that global warming could bring serious changes to Antarctic ecosystems.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected”

“This finding shows us that living plants and animals can reach Antarctica across the ocean, with temperate and sub-Antarctic marine species probably bombarding Antarctic coastlines all the time,” said Ceridwen Fraser, of the Australian National University.

“We always thought Antarctic plants and animals were distinct because they were isolated, but this research now suggests these differences are almost entirely due to environmental extremes, not isolation.”

Dr Fraser and her colleagues report in the journal Nature Climate Change that strands of southern bull kelp, Durvillaea antarctica, found by a Chilean scientist, must have floated 20,000 km from the Kerguelen Islands and South Georgia. The kelp was encrusted with barnacles, evidence of a long time adrift.

In fact, researchers believe, it may be evidence of the longest episode of “biological rafting” ever confirmed. The word raft is significant: such floating platforms could provide shelter and transport for other biological invaders.

Plastic next?

Until now, the assumption has been that the pattern of surface currents and westerly winds tends to drive drifting material northwards from Antarctica. The discovery suggests that if kelp can get there, so can floating driftwood, or plastic debris, or any other unwelcome visitor.

The researchers think large waves driven by Southern Ocean storms may have steered the kelp rafts over what had been considered a natural ocean barrier. Global warming has begun to change conditions in Antarctica, and the continent – considered the last great tract of terrain unmarked by human colonisation – could become increasingly vulnerable to change.

“This is an unequivocal demonstration that marine species from the north can reach Antarctica. To get there the kelp had to pass through barriers created by polar winds and currents that were, until now, thought to be impenetrable,” Dr Fraser said.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected.” – Climate News Network

Rising seas’ cost may be $27tn a year by 2100

In 80 years the rising seas’ cost may be $27tn a year globally, with the oceans possibly nearing two metres above their present levels.

LONDON, 4 July, 2018 – The rising seas’ cost may be US$27tn a year for the world by 2100 if it fails to meet the UN’s 2ºC global warming limit by then, with sea level rise of, at its worst, almost six feet (nearly two metres), new research says.

A study led by the UK’s National Oceanography Centre (NOC) says the worldwide cost of flooding caused by rising sea levels, at their median level, could by 2100 be $14 trillion, if governments miss the United Nations target of keeping the rise in global temperatures, caused by unremitting fossil fuel use, to less than 2ºC above pre-industrial levels. But the extent and cost could be much higher.

The target was agreed by 195 nations in Paris in 2015, with many politicians and most scientists urging them to treat 2ºC as a more modest and feasible limit while aiming if possible for 1.5°C. The cuts in greenhouse gas emissions already promised through the UN Framework Convention on Climate Change are not yet enough to achieve the 2ºC limit, let alone the more stringent figure, and much deeper cuts will be needed.

“These results place further emphasis on putting even greater efforts into mitigating rising global temperatures”

The researchers also found that it was upper-middle income countries such as China that would see the largest increase in flood costs, while the richest ones would suffer the least, because of the high levels of protection infrastructure they already enjoyed. The research is published in the journal Environmental Research Letters.

Svetlana Jevrejeva of the NOC is the study’s lead author. She said: “More than 600 million people live in low-elevation coastal areas, less than 10 metres above sea level. In a warming climate, global sea level will rise due to the melting of land-based glaciers and ice sheets, and from the thermal expansion of ocean waters. So sea level rise is one of the most damaging aspects of our warming climate.”

The researchers explored the pace and consequences of global and regional sea level rise under warming limited to both 1.5 ºC and 2 ºC, and compared their findings with projections for unmitigated warming.

Using World Bank income groups (high, upper-middle, lower-middle and low income countries), they then assessed the impact of sea level rise in coastal areas from a global perspective.

Steep increase

Dr Jevrejeva said: “We found that with a temperature rise trajectory of 1.5°C, by 2100 the median sea level will have risen by 0.52m (1.7ft). But, if the 2°C target is missed, we will see a median sea level rise of 0.86m (2.8ft), and a worst-case rise of 1.8m (5.9ft).”

If warming was not mitigated the global annual flood costs without adaptation would increase to $14tn annually for the median sea level rise of 0.86m, and up to $27tn per year for 1.8m. This would account for 2.8% of global GDP in 2100.

The conclusions she and her colleagues reached sound hair-raising and possibly far-fetched. But an earlier study put the possible global cost by 2100 of coastal flooding at nearly four times more than the NOC team – $100tn.

Another group of researchers suggested that if global warming continued at its present rate it could start a process in Antarctica which would lead ultimately to sea level rise of almost three metres.

Impact on tropics

The projected difference in coastal sea levels is also likely to mean that tropical areas will see very high sea levels more often, the study says.

“These extreme sea levels will have a negative effect on the economies of developing coastal nations, and the habitability of low-lying coastlines,” said Dr Jevrejeva.

“Small, low-lying island nations such as the Maldives will be very easily affected, and the pressures on their natural resources and environment will become even greater.

“These results place further emphasis on putting even greater efforts into mitigating rising global temperatures.” – Climate News Network

In 80 years the rising seas’ cost may be $27tn a year globally, with the oceans possibly nearing two metres above their present levels.

LONDON, 4 July, 2018 – The rising seas’ cost may be US$27tn a year for the world by 2100 if it fails to meet the UN’s 2ºC global warming limit by then, with sea level rise of, at its worst, almost six feet (nearly two metres), new research says.

A study led by the UK’s National Oceanography Centre (NOC) says the worldwide cost of flooding caused by rising sea levels, at their median level, could by 2100 be $14 trillion, if governments miss the United Nations target of keeping the rise in global temperatures, caused by unremitting fossil fuel use, to less than 2ºC above pre-industrial levels. But the extent and cost could be much higher.

The target was agreed by 195 nations in Paris in 2015, with many politicians and most scientists urging them to treat 2ºC as a more modest and feasible limit while aiming if possible for 1.5°C. The cuts in greenhouse gas emissions already promised through the UN Framework Convention on Climate Change are not yet enough to achieve the 2ºC limit, let alone the more stringent figure, and much deeper cuts will be needed.

“These results place further emphasis on putting even greater efforts into mitigating rising global temperatures”

The researchers also found that it was upper-middle income countries such as China that would see the largest increase in flood costs, while the richest ones would suffer the least, because of the high levels of protection infrastructure they already enjoyed. The research is published in the journal Environmental Research Letters.

Svetlana Jevrejeva of the NOC is the study’s lead author. She said: “More than 600 million people live in low-elevation coastal areas, less than 10 metres above sea level. In a warming climate, global sea level will rise due to the melting of land-based glaciers and ice sheets, and from the thermal expansion of ocean waters. So sea level rise is one of the most damaging aspects of our warming climate.”

The researchers explored the pace and consequences of global and regional sea level rise under warming limited to both 1.5 ºC and 2 ºC, and compared their findings with projections for unmitigated warming.

Using World Bank income groups (high, upper-middle, lower-middle and low income countries), they then assessed the impact of sea level rise in coastal areas from a global perspective.

Steep increase

Dr Jevrejeva said: “We found that with a temperature rise trajectory of 1.5°C, by 2100 the median sea level will have risen by 0.52m (1.7ft). But, if the 2°C target is missed, we will see a median sea level rise of 0.86m (2.8ft), and a worst-case rise of 1.8m (5.9ft).”

If warming was not mitigated the global annual flood costs without adaptation would increase to $14tn annually for the median sea level rise of 0.86m, and up to $27tn per year for 1.8m. This would account for 2.8% of global GDP in 2100.

The conclusions she and her colleagues reached sound hair-raising and possibly far-fetched. But an earlier study put the possible global cost by 2100 of coastal flooding at nearly four times more than the NOC team – $100tn.

Another group of researchers suggested that if global warming continued at its present rate it could start a process in Antarctica which would lead ultimately to sea level rise of almost three metres.

Impact on tropics

The projected difference in coastal sea levels is also likely to mean that tropical areas will see very high sea levels more often, the study says.

“These extreme sea levels will have a negative effect on the economies of developing coastal nations, and the habitability of low-lying coastlines,” said Dr Jevrejeva.

“Small, low-lying island nations such as the Maldives will be very easily affected, and the pressures on their natural resources and environment will become even greater.

“These results place further emphasis on putting even greater efforts into mitigating rising global temperatures.” – Climate News Network

Stormier weather ahead raises fishing risks

A warmer world means stormier weather ahead, and ever-greater dangers for those who work in the world’s commercial fishing fleets.

LONDON, 2 July, 2018 – Here is the shipping forecast for the next two centuries: there’s stormier weather ahead. Typhoons will be on the increase in the east China Sea. There will be a greater frequency of post-monsoon storms in the Arabian Sea.

The forecast for the Mediterranean is somewhat milder: storms could be reduced over the next 200 years. But the outlook for the northeast Atlantic is not good: autumn and winter storms are likely to increase, both in number and in intensity, off the coasts of the UK, Ireland and France.

And the impact on the fishing industry could, say the authors of a new study, be catastrophic.

Around 38 million people worldwide already engage in capture fishing, according to a study in Nature Climate Change. They regularly, the scientists say, “risk their lives in one of the most dangerous jobs on Earth.”

And as a consequence of climate change driven by global warming, fuelled by profligate combustion of fossil fuels that increase the levels of greenhouse gases in the atmosphere, fishing is about to become even more dangerous.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people”

Global warming has already begun to affect commercial fishing. As waters warm, fish begin to shift their grounds, both in the warmer seas and in the colder waters that have supported fishing industries for centuries, with troubling consequences both for international tensions  and for future diets.

The researchers report that although warming could certainly alter the potential fish catch over the next 50 to 100 years, “changing storminess has the potential to cause more immediate and catastrophic impacts.”

And they argue that once researchers understand better how the fisheries industry and community cope with stormy weather, there might be ways to adjust practices and safeguard both lives and livelihoods.

Between them, capture fisheries – with trawls, seine nets and long lines – and aquaculture, or fish farming, support the livelihoods of 12% of the global population. Fish provide more than 3 billion people with around one-fifth of their animal protein: there is a lot at stake.

Fish at risk

And storms are a threat not just to fishing crews but to the fish as well. Warming waters change the composition of submarine populations and in effect gradually alter the local ecosystems. But severe storms can displace whole fish populations, interfere with the dispersal of the larvae that will become fish, and even destroy the habitat that fish depend upon.

The scientists want to see a co-ordinated examination of the hazards ahead, drawing upon expertise from psychologists, anthropologists and economists as well as marine scientists and climatologists.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people around the world who rely on fish for their daily nutrition,” said Nigel Sainsbury, a social scientist at the University of Exeter, UK, who led the study.

“Changing storminess could have serious consequences for vulnerable coastal communities around the world. Conducting research in this area is critical to support the adaptation of fisheries to climate change.” – Climate News Network

A warmer world means stormier weather ahead, and ever-greater dangers for those who work in the world’s commercial fishing fleets.

LONDON, 2 July, 2018 – Here is the shipping forecast for the next two centuries: there’s stormier weather ahead. Typhoons will be on the increase in the east China Sea. There will be a greater frequency of post-monsoon storms in the Arabian Sea.

The forecast for the Mediterranean is somewhat milder: storms could be reduced over the next 200 years. But the outlook for the northeast Atlantic is not good: autumn and winter storms are likely to increase, both in number and in intensity, off the coasts of the UK, Ireland and France.

And the impact on the fishing industry could, say the authors of a new study, be catastrophic.

Around 38 million people worldwide already engage in capture fishing, according to a study in Nature Climate Change. They regularly, the scientists say, “risk their lives in one of the most dangerous jobs on Earth.”

And as a consequence of climate change driven by global warming, fuelled by profligate combustion of fossil fuels that increase the levels of greenhouse gases in the atmosphere, fishing is about to become even more dangerous.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people”

Global warming has already begun to affect commercial fishing. As waters warm, fish begin to shift their grounds, both in the warmer seas and in the colder waters that have supported fishing industries for centuries, with troubling consequences both for international tensions  and for future diets.

The researchers report that although warming could certainly alter the potential fish catch over the next 50 to 100 years, “changing storminess has the potential to cause more immediate and catastrophic impacts.”

And they argue that once researchers understand better how the fisheries industry and community cope with stormy weather, there might be ways to adjust practices and safeguard both lives and livelihoods.

Between them, capture fisheries – with trawls, seine nets and long lines – and aquaculture, or fish farming, support the livelihoods of 12% of the global population. Fish provide more than 3 billion people with around one-fifth of their animal protein: there is a lot at stake.

Fish at risk

And storms are a threat not just to fishing crews but to the fish as well. Warming waters change the composition of submarine populations and in effect gradually alter the local ecosystems. But severe storms can displace whole fish populations, interfere with the dispersal of the larvae that will become fish, and even destroy the habitat that fish depend upon.

The scientists want to see a co-ordinated examination of the hazards ahead, drawing upon expertise from psychologists, anthropologists and economists as well as marine scientists and climatologists.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people around the world who rely on fish for their daily nutrition,” said Nigel Sainsbury, a social scientist at the University of Exeter, UK, who led the study.

“Changing storminess could have serious consequences for vulnerable coastal communities around the world. Conducting research in this area is critical to support the adaptation of fisheries to climate change.” – Climate News Network

Warmer world needs more protected habitat

With climate change soon to be the main threat to biodiversity, protected habitat will be a higher priority than ever to give wildlife a chance.

LONDON, 25 June, 2018 – Some time later this century, the world’s need for protected habitat will be more acute even than today.

The greatest danger to the wild vertebrates that roam the planet will not be the intruding humans, their livestock and their pesticides and herbicides. It will be human-induced global warming and climate change.

The conversion of wilderness – forest, grassland and swamp – to urban growth, agriculture and pasture has already caused losses of perhaps one species in 10 in the natural ecosystems disturbed by humankind.

But what could be catastrophic climate change driven by profligate human burning of fossil fuels could by 2070 overtake the damage delivered by changes in the way land is used, with catastrophic consequences for birds, reptiles, mammals and other vertebrates.

Losses could reach 20% or even 40%, according to a new study in an academic journal, the Proceedings of the Royal Society B.

“The current target of protecting 17% of terrestrial systems will never be enough to protect species as well as provide the benefits humanity needs”

And a second, separate study in another journal spells out the challenge for governments, communities and conservators: the present targets for biodiversity conservation are simply inadequate. They leave 83% of the land surface unprotected, and 90% of the oceans not effectively conserved.

There have been calls to set at least half of the globe aside for the wild animals, plants and fungi that – until human numbers began to expand – dominated the planet. But the latest study, in the journal Nature Ecology and Evolution, suggests that even a half-share for nature might not be enough to save many species from extinction.

Researchers have been warning for two decades that climate change poses a real threat to the thousands of known species of wild creature, and millions of plants and animals yet to be identified and monitored.

They have argued that climate change will damage the forests that provide a natural home for countless forms of life; that global warming already presents dangers for known species; and that climate change may already have claimed more victims than anyone has so far realised.

Natural answer

They have also, in different ways, proved again and again that rich, biodiverse habitats, especially forests, are part of the natural machinery for limiting climate change – and in any case, in simple cash terms, forests are worth more to humankind as natural forests than as plantations, or cattle ranches.

And to rub home the message a third study in the same week, in the Journal of Animal Ecology, highlights the direct dangers of warmer sea waters to the colonies of black-browed albatross in the Southern Ocean. Meticulous monitoring since 1979 has showed that the biggest variation in population growth depends simply on sea water temperatures as the juvenile birds set off for their first year of independence over the open sea.

The cold Antarctic waters are rich in dissolved oxygen and support enormous levels of plant and tiny animal life on which the birds, fish and sea mammals depend. As waters warm, food becomes less available.

“As our oceans are projected to warm, fewer juvenile albatrosses will manage to survive and populations are expected to decline at a faster rate,” said Stéphanie Jenouvrier, of the Woods Hole Oceanographic Institution in the US.

The albatross populations of the Southern Hemisphere are already vulnerable: climate change will make them even more at hazard. And researchers have already pointed out that although great tracts of the world have already been declared reserves, many of those territories already protected have been systematically degraded by human invasion.

Heavy demands

“Humanity asks a lot of the natural world. We need it to purify our water and air, to maintain our soils, and to regulate our climate,” said Martine Maron of the University of Queensland, Australia, who led the Royal Society study.

“Yet even as we increase the extent of protected areas, they don’t necessarily prevent the loss of natural systems. They’re often located in areas that might not have been lost anyway – and the current target of protecting 17% of terrestrial systems will never be enough to protect species as well as provide the benefits humanity needs.”

And her co-author James Watson, of the Wildlife Conservation Society, who is also based at the University of Queensland, said: “We need a big, bold plan.

“There is no doubt that when we add up the different environmental goals to halt biodiversity loss, stabilise runaway climate change and to ensure other critical ecosystems services such as pollination and clean water are maintained, we will need far more than 50% of the Earth’s natural systems to remain intact.” – Climate News Network

With climate change soon to be the main threat to biodiversity, protected habitat will be a higher priority than ever to give wildlife a chance.

LONDON, 25 June, 2018 – Some time later this century, the world’s need for protected habitat will be more acute even than today.

The greatest danger to the wild vertebrates that roam the planet will not be the intruding humans, their livestock and their pesticides and herbicides. It will be human-induced global warming and climate change.

The conversion of wilderness – forest, grassland and swamp – to urban growth, agriculture and pasture has already caused losses of perhaps one species in 10 in the natural ecosystems disturbed by humankind.

But what could be catastrophic climate change driven by profligate human burning of fossil fuels could by 2070 overtake the damage delivered by changes in the way land is used, with catastrophic consequences for birds, reptiles, mammals and other vertebrates.

Losses could reach 20% or even 40%, according to a new study in an academic journal, the Proceedings of the Royal Society B.

“The current target of protecting 17% of terrestrial systems will never be enough to protect species as well as provide the benefits humanity needs”

And a second, separate study in another journal spells out the challenge for governments, communities and conservators: the present targets for biodiversity conservation are simply inadequate. They leave 83% of the land surface unprotected, and 90% of the oceans not effectively conserved.

There have been calls to set at least half of the globe aside for the wild animals, plants and fungi that – until human numbers began to expand – dominated the planet. But the latest study, in the journal Nature Ecology and Evolution, suggests that even a half-share for nature might not be enough to save many species from extinction.

Researchers have been warning for two decades that climate change poses a real threat to the thousands of known species of wild creature, and millions of plants and animals yet to be identified and monitored.

They have argued that climate change will damage the forests that provide a natural home for countless forms of life; that global warming already presents dangers for known species; and that climate change may already have claimed more victims than anyone has so far realised.

Natural answer

They have also, in different ways, proved again and again that rich, biodiverse habitats, especially forests, are part of the natural machinery for limiting climate change – and in any case, in simple cash terms, forests are worth more to humankind as natural forests than as plantations, or cattle ranches.

And to rub home the message a third study in the same week, in the Journal of Animal Ecology, highlights the direct dangers of warmer sea waters to the colonies of black-browed albatross in the Southern Ocean. Meticulous monitoring since 1979 has showed that the biggest variation in population growth depends simply on sea water temperatures as the juvenile birds set off for their first year of independence over the open sea.

The cold Antarctic waters are rich in dissolved oxygen and support enormous levels of plant and tiny animal life on which the birds, fish and sea mammals depend. As waters warm, food becomes less available.

“As our oceans are projected to warm, fewer juvenile albatrosses will manage to survive and populations are expected to decline at a faster rate,” said Stéphanie Jenouvrier, of the Woods Hole Oceanographic Institution in the US.

The albatross populations of the Southern Hemisphere are already vulnerable: climate change will make them even more at hazard. And researchers have already pointed out that although great tracts of the world have already been declared reserves, many of those territories already protected have been systematically degraded by human invasion.

Heavy demands

“Humanity asks a lot of the natural world. We need it to purify our water and air, to maintain our soils, and to regulate our climate,” said Martine Maron of the University of Queensland, Australia, who led the Royal Society study.

“Yet even as we increase the extent of protected areas, they don’t necessarily prevent the loss of natural systems. They’re often located in areas that might not have been lost anyway – and the current target of protecting 17% of terrestrial systems will never be enough to protect species as well as provide the benefits humanity needs.”

And her co-author James Watson, of the Wildlife Conservation Society, who is also based at the University of Queensland, said: “We need a big, bold plan.

“There is no doubt that when we add up the different environmental goals to halt biodiversity loss, stabilise runaway climate change and to ensure other critical ecosystems services such as pollination and clean water are maintained, we will need far more than 50% of the Earth’s natural systems to remain intact.” – Climate News Network

Antarctic buffer damage spurs ice break-up

The Antarctic buffer which has for millennia sheltered the continent’s huge inland ice sheet is being battered by seaborne wave action.

LONDON, 21 June, 2018 – The vast southern ice sheet, despite the Antarctic buffer which has protected it for so long, is now being threatened by ocean swells chipping away at the continent’s coastal edge, says a new study by US scientists published in the journal Nature.

For millennia the southern ice sheet has had this protective buffer of sea ice ringing its coastal shelves. But now the swells from the north are flexing them and can weaken their stabilising seaward edge. Regular inundation by summer meltwater as the edge breaks away can also contribute to rapid ice shelf disintegration.

Ice shelves, with their ring of sea ice, are thick plates of ice fed by tributary glaciers, floating seaward extensions of the massive grounded inland ice sheet. They slow the flow of ice from the sheet, so rapidly disintegrating shelves have implications for sea level rise.

“Sea ice here acts like the bumpers on a car – with the bumpers in place, the car can take a shock and not be damaged. Take them off, and every hit adds up,” said Ted Scambos, study co-author and senior research scientist at the National Snow and Ice Data Center at the University of Colorado Boulder.

Since 1995, three large ice shelves on the Antarctic Peninsula – Larsen A, Larsen B and Wilkins – have suddenly and dramatically disintegrated.
Occurring over a few weeks, or sometimes even only a few days, these break-ups mark an unprecedented departure from the more typical and natural recurring calving of larger icebergs every decade or so.

Trigger found

Until recently researchers had thought intense surface melting caused by a warming climate and ice fracturing were the sole culprits. But the new findings suggest that loss of sea ice and the calving of the seaward edge into narrow sliver-like icebergs are the trigger that sets off a rapid ice shelf disintegration.

“Our study breaks new ground in how it implicates sea ice change in sea level rise,” said Rob Massom, the study’s lead author and a senior research scientist at the Australian Antarctic Division and Antarctic Climate and Ecosystems Cooperative Research Centre.

“It introduces ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer as the straw that breaks the camel’s back.”

He and his colleagues analysed disintegrations on three ice shelves that had been stable for centuries or even millennia: Larsen A in 1995, Larsen B in 2002, and Wilkins in 2008 and 2009.

They confirmed that atmospheric warming led to increased meltwater on the surfaces of the shelves. Pooled meltwater then percolated downward through crevasses, setting off a hydrofracturing process that weakened the ice.

“Ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer [is] the straw that breaks the camel’s back”

Earlier studies have identified the central role that ice shelves play in making sea level rise more likely and the accelerating pace of Antarctic melting.

But, crucially, what the NSIDC analysis reveals is a previously little-recognised link to sea ice: all three disintegrations happened when there was little or no sea ice cover along the shelf edge. Without that protective buffer, the shelves became exposed to waves which flexed the already fractured ice.

“What we’ve found is that increased flexing of the outer parts of ice shelves by waves sets the ice up for destruction. Even though the movement is tiny, over time the shelf is weakened,” Scambos said.

In each case, ocean swells began affecting the ice shelf edge. As the shelves flexed, existing fractures along the seaward edge chipped off as long, thin, sliver-shaped icebergs, not the larger tabular icebergs more typical of Antarctic ice shelf calvings. The remaining ice shelf was then ripe for runaway collapse.

“Other ice shelves can survive for centuries if they don’t have surface meltwater – or if the water can run off easily,” Scambos said. “But with meltwater ponding and a legacy of weakening from sea ice loss, you can destroy a shelf in just a few weeks.”

Pressure off

Because ice shelves are already floating in the ocean and displacing their volume, like ice cubes in a glass of water, their disintegration does not contribute directly to sea level rise.

But they do provide a backpressure that moderates glacier flow speed. Once they’re gone, so is the backpressure, allowing the glaciers to flow more rapidly into the ocean and ultimately contribute to sea level rise.

“This represents an important pathway towards reducing current large uncertainty in predictions of the response of the Antarctic cryosphere to climate change and its contribution to sea level rise,” Dr Massom said.

The Antarctic ice sheet contains enough ice to raise sea level by approximately 57 metres (187 feet), about half the length of a soccer pitch. Worldwide, more than 100 million people currently live within 1m of mean sea level. – Climate News Network

The Antarctic buffer which has for millennia sheltered the continent’s huge inland ice sheet is being battered by seaborne wave action.

LONDON, 21 June, 2018 – The vast southern ice sheet, despite the Antarctic buffer which has protected it for so long, is now being threatened by ocean swells chipping away at the continent’s coastal edge, says a new study by US scientists published in the journal Nature.

For millennia the southern ice sheet has had this protective buffer of sea ice ringing its coastal shelves. But now the swells from the north are flexing them and can weaken their stabilising seaward edge. Regular inundation by summer meltwater as the edge breaks away can also contribute to rapid ice shelf disintegration.

Ice shelves, with their ring of sea ice, are thick plates of ice fed by tributary glaciers, floating seaward extensions of the massive grounded inland ice sheet. They slow the flow of ice from the sheet, so rapidly disintegrating shelves have implications for sea level rise.

“Sea ice here acts like the bumpers on a car – with the bumpers in place, the car can take a shock and not be damaged. Take them off, and every hit adds up,” said Ted Scambos, study co-author and senior research scientist at the National Snow and Ice Data Center at the University of Colorado Boulder.

Since 1995, three large ice shelves on the Antarctic Peninsula – Larsen A, Larsen B and Wilkins – have suddenly and dramatically disintegrated.
Occurring over a few weeks, or sometimes even only a few days, these break-ups mark an unprecedented departure from the more typical and natural recurring calving of larger icebergs every decade or so.

Trigger found

Until recently researchers had thought intense surface melting caused by a warming climate and ice fracturing were the sole culprits. But the new findings suggest that loss of sea ice and the calving of the seaward edge into narrow sliver-like icebergs are the trigger that sets off a rapid ice shelf disintegration.

“Our study breaks new ground in how it implicates sea ice change in sea level rise,” said Rob Massom, the study’s lead author and a senior research scientist at the Australian Antarctic Division and Antarctic Climate and Ecosystems Cooperative Research Centre.

“It introduces ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer as the straw that breaks the camel’s back.”

He and his colleagues analysed disintegrations on three ice shelves that had been stable for centuries or even millennia: Larsen A in 1995, Larsen B in 2002, and Wilkins in 2008 and 2009.

They confirmed that atmospheric warming led to increased meltwater on the surfaces of the shelves. Pooled meltwater then percolated downward through crevasses, setting off a hydrofracturing process that weakened the ice.

“Ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer [is] the straw that breaks the camel’s back”

Earlier studies have identified the central role that ice shelves play in making sea level rise more likely and the accelerating pace of Antarctic melting.

But, crucially, what the NSIDC analysis reveals is a previously little-recognised link to sea ice: all three disintegrations happened when there was little or no sea ice cover along the shelf edge. Without that protective buffer, the shelves became exposed to waves which flexed the already fractured ice.

“What we’ve found is that increased flexing of the outer parts of ice shelves by waves sets the ice up for destruction. Even though the movement is tiny, over time the shelf is weakened,” Scambos said.

In each case, ocean swells began affecting the ice shelf edge. As the shelves flexed, existing fractures along the seaward edge chipped off as long, thin, sliver-shaped icebergs, not the larger tabular icebergs more typical of Antarctic ice shelf calvings. The remaining ice shelf was then ripe for runaway collapse.

“Other ice shelves can survive for centuries if they don’t have surface meltwater – or if the water can run off easily,” Scambos said. “But with meltwater ponding and a legacy of weakening from sea ice loss, you can destroy a shelf in just a few weeks.”

Pressure off

Because ice shelves are already floating in the ocean and displacing their volume, like ice cubes in a glass of water, their disintegration does not contribute directly to sea level rise.

But they do provide a backpressure that moderates glacier flow speed. Once they’re gone, so is the backpressure, allowing the glaciers to flow more rapidly into the ocean and ultimately contribute to sea level rise.

“This represents an important pathway towards reducing current large uncertainty in predictions of the response of the Antarctic cryosphere to climate change and its contribution to sea level rise,” Dr Massom said.

The Antarctic ice sheet contains enough ice to raise sea level by approximately 57 metres (187 feet), about half the length of a soccer pitch. Worldwide, more than 100 million people currently live within 1m of mean sea level. – Climate News Network