Category Archives: Oceans

Food supply falls as fish flee warmer seas

On the fishing grounds, they already know about global warming. As fish flee warmer seas there are winners – but many more losers.

LONDON, 4 March 2019 – Global warming has already begun to affect fishing worldwide as fish flee warmer seas, a new study says.

In the last 80 years, there has been an estimated drop of more than 4% in sustainable catches for many kinds of fish and shellfish. That is the average. In some regions – the East China Sea, for instance, and Europe’s North Sea –  the estimated decline was between 15% and 35%.

In the course of the last century, global average temperatures have crept up by about 1°C above the average for most of human history, as a reaction to the unconstrained burning of fossil fuels. If the world continues to burn ever-greater volumes of coal, oil and natural gas, it could be 3°C warmer or more by the end of the century.

Last year was only the fourth warmest for air surface temperatures, but the warmest since records began for the world’s oceans.

“Fisheries around the world have already responded to global warming. These aren’t hypothetical changes some time in the future”

US researchers report in the journal Science that they looked at the impact of ocean warming in 235 populations of 124 species of fish, crustaceans and molluscs in 38 ecological regions between the years 1930 and 2010.

They then matched the world data on fish catches with ocean temperature maps to estimate what warming has done to the sustainable catch – that is, the biggest haul fishing crews can make without reducing breeding stocks for the seasons to follow.

“We were stunned to find that fisheries around the world have already responded to global warming,” said Malin Pinsky of Rutgers University, and one of the authors. “These aren’t hypothetical changes some time in the future.”

The researchers found that some species in some climate zones actually benefited from warming, and fish with faster life cycles sometimes responded well, sometimes badly to the temperature changes. Some responded by shifting their geographical range.

More climate losers

But overall, said Christopher Free, once of Rutgers and now at the University of California, Santa Barbara, “among the populations we studied, the climate losers outweigh the climate winners.”

And his colleague Olaf Jensen, also from Rutgers, said: “Fish populations can only tolerate so much warning, though. Many of the species that have benefited from warming so far are likely to start declining as temperatures continue to rise.”

Fishermen off the coasts of Labrador and Newfoundland, in the Baltic, the Indian Ocean and the northeast US shelf may have seen more productive hauls of fish. But the biggest losses were in the Sea of Japan, the North Sea, off the Iberian coast and the Celtic-Biscay shelf.

Many fish species are adapted to a precise range of temperatures: they flourish not just in specific marine ecosystems but in thermal niches as well. Once things begin to change, they swim away or perish.

Marauding invaders

Fishermen in the North Atlantic have repeatedly observed changes in the available catch, as the cod shift north and the sardines migrate from increasingly uncomfortable warm waters. Warming in Mediterranean waters creates enticing conditions for invaders from the Red Sea and further south, at huge cost to the resident species.

The lesson is that fish stocks must be carefully conserved, and ocean reserves protected. Researchers have consistently warned that global warming and climate change – especially when combined with changes in ocean water chemistry as a consequence of carbon dioxide build-up in the atmosphere – could soon start to constrain an important source of nutrition: an estimated 3.2 billion people rely on the sea for an estimated 20% of their animal protein, especially in East Asia.

“This means 15% to 35% less fish available for food and employment in a region with some of the fastest-growing human populations in the world,” said Dr Free.

“Knowing exactly how fisheries will change under future warming is challenging, but we do know that failing to adapt to changing fisheries productivity will result in less food and fewer profits relative to today.” – Climate News Network

On the fishing grounds, they already know about global warming. As fish flee warmer seas there are winners – but many more losers.

LONDON, 4 March 2019 – Global warming has already begun to affect fishing worldwide as fish flee warmer seas, a new study says.

In the last 80 years, there has been an estimated drop of more than 4% in sustainable catches for many kinds of fish and shellfish. That is the average. In some regions – the East China Sea, for instance, and Europe’s North Sea –  the estimated decline was between 15% and 35%.

In the course of the last century, global average temperatures have crept up by about 1°C above the average for most of human history, as a reaction to the unconstrained burning of fossil fuels. If the world continues to burn ever-greater volumes of coal, oil and natural gas, it could be 3°C warmer or more by the end of the century.

Last year was only the fourth warmest for air surface temperatures, but the warmest since records began for the world’s oceans.

“Fisheries around the world have already responded to global warming. These aren’t hypothetical changes some time in the future”

US researchers report in the journal Science that they looked at the impact of ocean warming in 235 populations of 124 species of fish, crustaceans and molluscs in 38 ecological regions between the years 1930 and 2010.

They then matched the world data on fish catches with ocean temperature maps to estimate what warming has done to the sustainable catch – that is, the biggest haul fishing crews can make without reducing breeding stocks for the seasons to follow.

“We were stunned to find that fisheries around the world have already responded to global warming,” said Malin Pinsky of Rutgers University, and one of the authors. “These aren’t hypothetical changes some time in the future.”

The researchers found that some species in some climate zones actually benefited from warming, and fish with faster life cycles sometimes responded well, sometimes badly to the temperature changes. Some responded by shifting their geographical range.

More climate losers

But overall, said Christopher Free, once of Rutgers and now at the University of California, Santa Barbara, “among the populations we studied, the climate losers outweigh the climate winners.”

And his colleague Olaf Jensen, also from Rutgers, said: “Fish populations can only tolerate so much warning, though. Many of the species that have benefited from warming so far are likely to start declining as temperatures continue to rise.”

Fishermen off the coasts of Labrador and Newfoundland, in the Baltic, the Indian Ocean and the northeast US shelf may have seen more productive hauls of fish. But the biggest losses were in the Sea of Japan, the North Sea, off the Iberian coast and the Celtic-Biscay shelf.

Many fish species are adapted to a precise range of temperatures: they flourish not just in specific marine ecosystems but in thermal niches as well. Once things begin to change, they swim away or perish.

Marauding invaders

Fishermen in the North Atlantic have repeatedly observed changes in the available catch, as the cod shift north and the sardines migrate from increasingly uncomfortable warm waters. Warming in Mediterranean waters creates enticing conditions for invaders from the Red Sea and further south, at huge cost to the resident species.

The lesson is that fish stocks must be carefully conserved, and ocean reserves protected. Researchers have consistently warned that global warming and climate change – especially when combined with changes in ocean water chemistry as a consequence of carbon dioxide build-up in the atmosphere – could soon start to constrain an important source of nutrition: an estimated 3.2 billion people rely on the sea for an estimated 20% of their animal protein, especially in East Asia.

“This means 15% to 35% less fish available for food and employment in a region with some of the fastest-growing human populations in the world,” said Dr Free.

“Knowing exactly how fisheries will change under future warming is challenging, but we do know that failing to adapt to changing fisheries productivity will result in less food and fewer profits relative to today.” – Climate News Network

Carbon rise could cause cloud tipping point

The planet’s temperature could zoom in an ever more greenhouse world, as researchers identify a dangerous possible cloud tipping point.

LONDON, 27 February, 2019 − Climate scientists have confirmed a high-level hazard, a cloud tipping point, that could send global warming into a dramatic upwards spiral.

If carbon dioxide concentrations in the atmosphere become high enough, the clouds that shade and cool some of the tropical and subtropical oceans could become unstable and disperse. More radiation would slam into the ocean and the coasts, and surface temperatures could soar as high as 8°C above the levels for most of human history.

And this dramatic spike would be independent of any warming directly linked to the steady rise in carbon dioxide concentrations themselves, the scientists warn.

In Paris in 2015, a total of 195 nations vowed to take steps to contain global warming to “well below” a maximum of 2°C above the average before the start of the Industrial Revolution, powered by the exploitation of fossil fuels.

In the last 200 years, levels of the greenhouse gas carbon dioxide in the atmosphere have increased from 288 parts per million to around 410 ppm and the average global temperature has already increased by about 1°C.

“Our results show that there are dangerous climate change thresholds that we have been unaware of”

Researchers have repeatedly warned that the Paris promises have yet to be turned into coherent and consistent action, and that if the world goes on burning coal, oil and natural gas on a “business as usual” scenario, catastrophic consequences could follow.

Now US researchers warn in the journal Nature Geoscience that they know a bit more about the climate mechanisms by which global warming could accelerate.

If carbon dioxide ratios climb to 1,200 ppm – and without drastic action this could happen in the next century – then the Earth could reach a tipping point, and the marine stratus clouds that shade one-fifth of the low-latitude oceans and reflect between 30% and 60% of shortwave radiation back into space could break up and scatter.

The sunlight they normally block would slam into the deep blue sea, to warm the planet even faster.

Avoidance possible

“I think and hope that technological changes will slow carbon emissions so that we do not actually reach such high CO2 concentrations,” said Tapio Schneider, an environmental scientist at the Jet Propulsion Laboratory, the research centre managed for the US space agency NASA by the California Institute of Technology.

“But our results show that there are dangerous climate change thresholds that we have been unaware of.”

The role of clouds in the intricate interplay of sunlight, forests, oceans, rocks and atmosphere that controls the planet’s climate has been the subject of argument. Do clouds really slow warming? And if so, by how much, and under what conditions?

There may not be a simple answer, although researchers are fairly confident that the thinning of clouds over the California coasts may have made calamitous wildfires in the state more probable.

So to resolve what Professor Schneider calls “a blind spot” in climate modelling, he and his colleagues worked on a small-scale computer simulation of one representative section of the atmosphere above the subtropical ocean, and then used supercomputers to model the clouds and their turbulent movement over a mathematical representation of the sea. And then they started to tune up the atmospheric concentrations of carbon dioxide.

Carbon threshold

They found that, once CO2 levels reached 1,200 ppm, the decks of stratocumulus cloud vanished, and did not reappear until CO2 levels dropped to well below this dangerous threshold.

If – and this has yet to happen – other researchers use different approaches to confirm the result, then the US scientists will have established a better understanding of one component of natural climate control.

The research may also illuminate a puzzle of climate history: 50 million or more years ago, during a geological epoch called the Eocene, the Arctic ice cap melted. Climate models have shown that, for this to happen, atmospheric carbon ratios would need to rise to 4,000 ppm.

These, the Caltech team, suggests, would be “implausibly high” CO2 levels. The latest study suggests this might be an overestimate: a mere 1,200 ppm would be enough to set the planetary thermometer soaring. − Climate News Network

The planet’s temperature could zoom in an ever more greenhouse world, as researchers identify a dangerous possible cloud tipping point.

LONDON, 27 February, 2019 − Climate scientists have confirmed a high-level hazard, a cloud tipping point, that could send global warming into a dramatic upwards spiral.

If carbon dioxide concentrations in the atmosphere become high enough, the clouds that shade and cool some of the tropical and subtropical oceans could become unstable and disperse. More radiation would slam into the ocean and the coasts, and surface temperatures could soar as high as 8°C above the levels for most of human history.

And this dramatic spike would be independent of any warming directly linked to the steady rise in carbon dioxide concentrations themselves, the scientists warn.

In Paris in 2015, a total of 195 nations vowed to take steps to contain global warming to “well below” a maximum of 2°C above the average before the start of the Industrial Revolution, powered by the exploitation of fossil fuels.

In the last 200 years, levels of the greenhouse gas carbon dioxide in the atmosphere have increased from 288 parts per million to around 410 ppm and the average global temperature has already increased by about 1°C.

“Our results show that there are dangerous climate change thresholds that we have been unaware of”

Researchers have repeatedly warned that the Paris promises have yet to be turned into coherent and consistent action, and that if the world goes on burning coal, oil and natural gas on a “business as usual” scenario, catastrophic consequences could follow.

Now US researchers warn in the journal Nature Geoscience that they know a bit more about the climate mechanisms by which global warming could accelerate.

If carbon dioxide ratios climb to 1,200 ppm – and without drastic action this could happen in the next century – then the Earth could reach a tipping point, and the marine stratus clouds that shade one-fifth of the low-latitude oceans and reflect between 30% and 60% of shortwave radiation back into space could break up and scatter.

The sunlight they normally block would slam into the deep blue sea, to warm the planet even faster.

Avoidance possible

“I think and hope that technological changes will slow carbon emissions so that we do not actually reach such high CO2 concentrations,” said Tapio Schneider, an environmental scientist at the Jet Propulsion Laboratory, the research centre managed for the US space agency NASA by the California Institute of Technology.

“But our results show that there are dangerous climate change thresholds that we have been unaware of.”

The role of clouds in the intricate interplay of sunlight, forests, oceans, rocks and atmosphere that controls the planet’s climate has been the subject of argument. Do clouds really slow warming? And if so, by how much, and under what conditions?

There may not be a simple answer, although researchers are fairly confident that the thinning of clouds over the California coasts may have made calamitous wildfires in the state more probable.

So to resolve what Professor Schneider calls “a blind spot” in climate modelling, he and his colleagues worked on a small-scale computer simulation of one representative section of the atmosphere above the subtropical ocean, and then used supercomputers to model the clouds and their turbulent movement over a mathematical representation of the sea. And then they started to tune up the atmospheric concentrations of carbon dioxide.

Carbon threshold

They found that, once CO2 levels reached 1,200 ppm, the decks of stratocumulus cloud vanished, and did not reappear until CO2 levels dropped to well below this dangerous threshold.

If – and this has yet to happen – other researchers use different approaches to confirm the result, then the US scientists will have established a better understanding of one component of natural climate control.

The research may also illuminate a puzzle of climate history: 50 million or more years ago, during a geological epoch called the Eocene, the Arctic ice cap melted. Climate models have shown that, for this to happen, atmospheric carbon ratios would need to rise to 4,000 ppm.

These, the Caltech team, suggests, would be “implausibly high” CO2 levels. The latest study suggests this might be an overestimate: a mere 1,200 ppm would be enough to set the planetary thermometer soaring. − Climate News Network

Melting polar ice sheets will alter weather

Sea level rise and melting polar ice sheets may not cause a climate catastrophe, but they will certainly change weather patterns unpredictably.

LONDON, 15 February, 2019 – The global weather is about to get worse. The melting polar ice sheets will mean rainfall and windstorms could become more violent, and hot spells and ice storms could become more extreme.

This is because the ice sheets of Greenland and Antarctica are melting, to affect what were once stable ocean currents and airflow patterns around the globe.

Planetary surface temperatures could rise by 3°C or even 4°C by the end of the century. Global sea levels will rise in ways that would “enhance global temperature variability”, but this might not be as high as earlier studies have predicted. That is because the ice cliffs of Antarctica might not be so much at risk of disastrous collapse that would set the glaciers accelerating to the sea.

The latest revision of evidence from the melting ice sheets in two hemispheres – and there is plenty of evidence that melting is happening at ever greater rates – is based on two studies of what could happen to the world’s greatest reservoirs of frozen freshwater if nations pursue current policies, fossil fuel combustion continues to increase, and global average temperatures creep up to unprecedented levels.

“Even if we do include ice-cliff instability … the most likely contribution to sea level rise would be less than half a metre by 2100”

“Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic ice sheets to enter Earth’s oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world,” said Nick Golledge, a south polar researcher at Victoria University, in New Zealand.

He and colleagues from Canada, the US, Germany and the UK report in Nature that they matched satellite observations of what is happening to the ice sheets with detailed simulations of the complex effects of melting over time, and according to the human response so far to warnings of climate change.

In Paris in 2015, leaders from 195 nations vowed to contain global warming to “well below” an average rise of 2°C by 2100. But promises have yet to become concerted and coherent action, and researchers warn that on present policies, a 3°C rise seems inevitable.

Sea levels have already risen by about 14 cms in the last century: the worst scenarios have proposed a devastating rise of 130 cms by 2100. The fastest increase in the rise of sea levels is likely to happen between 2065 and 2075.

Gulf Stream weakens

As warmer melt water gets into the North Atlantic, that major ocean current the Gulf Stream is likely to be weakened. Air temperatures are likely to rise over eastern Canada, central America and the high Arctic. Northwestern Europe – scientists have been warning of this for years – will become cooler.

In the Antarctic, a lens of warm fresh water will form over the surface, allowing uprising warm ocean water to spread and cause what could be further Antarctic melting.

But how bad this could be is re-examined in a second, companion paper in Nature. Tamsin Edwards, now at King’s College London, Dr Golledge and others took a fresh look at an old scare: that the vast cliffs of ice – some of them 100 metres above sea level – around the Antarctic could become unstable and collapse, accelerating the retreat of the ice behind them.

They used geophysical techniques to analyse dramatic episodes of ice loss that must have happened 3 million years ago and 125,000 years ago, and they went back to the present patterns of melt. These losses, in their calculations, did not cause unstoppable ice loss in the past, and may not affect the future much either.

Instability less important

“We’ve shown that ice-cliff instability doesn’t appear to be an essential mechanism in reproducing past sea level changes and so this suggests ‘the jury’s still out’ when it comes to including it in future predictions,” said Dr Edwards.

“Even if we do include ice-cliff instability, our more thorough assessment shows the most likely contribution to sea level rise would be less than half a metre by 2100.”

At worst, there is a one in 20 chance that enough of Antarctica’s glacial burden will melt to raise sea levels by 39 cms. More likely, both studies conclude, under high levels of greenhouse gas concentrations, south polar ice will only melt to raise sea levels worldwide by about 15 cms. – Climate News Network

Sea level rise and melting polar ice sheets may not cause a climate catastrophe, but they will certainly change weather patterns unpredictably.

LONDON, 15 February, 2019 – The global weather is about to get worse. The melting polar ice sheets will mean rainfall and windstorms could become more violent, and hot spells and ice storms could become more extreme.

This is because the ice sheets of Greenland and Antarctica are melting, to affect what were once stable ocean currents and airflow patterns around the globe.

Planetary surface temperatures could rise by 3°C or even 4°C by the end of the century. Global sea levels will rise in ways that would “enhance global temperature variability”, but this might not be as high as earlier studies have predicted. That is because the ice cliffs of Antarctica might not be so much at risk of disastrous collapse that would set the glaciers accelerating to the sea.

The latest revision of evidence from the melting ice sheets in two hemispheres – and there is plenty of evidence that melting is happening at ever greater rates – is based on two studies of what could happen to the world’s greatest reservoirs of frozen freshwater if nations pursue current policies, fossil fuel combustion continues to increase, and global average temperatures creep up to unprecedented levels.

“Even if we do include ice-cliff instability … the most likely contribution to sea level rise would be less than half a metre by 2100”

“Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic ice sheets to enter Earth’s oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world,” said Nick Golledge, a south polar researcher at Victoria University, in New Zealand.

He and colleagues from Canada, the US, Germany and the UK report in Nature that they matched satellite observations of what is happening to the ice sheets with detailed simulations of the complex effects of melting over time, and according to the human response so far to warnings of climate change.

In Paris in 2015, leaders from 195 nations vowed to contain global warming to “well below” an average rise of 2°C by 2100. But promises have yet to become concerted and coherent action, and researchers warn that on present policies, a 3°C rise seems inevitable.

Sea levels have already risen by about 14 cms in the last century: the worst scenarios have proposed a devastating rise of 130 cms by 2100. The fastest increase in the rise of sea levels is likely to happen between 2065 and 2075.

Gulf Stream weakens

As warmer melt water gets into the North Atlantic, that major ocean current the Gulf Stream is likely to be weakened. Air temperatures are likely to rise over eastern Canada, central America and the high Arctic. Northwestern Europe – scientists have been warning of this for years – will become cooler.

In the Antarctic, a lens of warm fresh water will form over the surface, allowing uprising warm ocean water to spread and cause what could be further Antarctic melting.

But how bad this could be is re-examined in a second, companion paper in Nature. Tamsin Edwards, now at King’s College London, Dr Golledge and others took a fresh look at an old scare: that the vast cliffs of ice – some of them 100 metres above sea level – around the Antarctic could become unstable and collapse, accelerating the retreat of the ice behind them.

They used geophysical techniques to analyse dramatic episodes of ice loss that must have happened 3 million years ago and 125,000 years ago, and they went back to the present patterns of melt. These losses, in their calculations, did not cause unstoppable ice loss in the past, and may not affect the future much either.

Instability less important

“We’ve shown that ice-cliff instability doesn’t appear to be an essential mechanism in reproducing past sea level changes and so this suggests ‘the jury’s still out’ when it comes to including it in future predictions,” said Dr Edwards.

“Even if we do include ice-cliff instability, our more thorough assessment shows the most likely contribution to sea level rise would be less than half a metre by 2100.”

At worst, there is a one in 20 chance that enough of Antarctica’s glacial burden will melt to raise sea levels by 39 cms. More likely, both studies conclude, under high levels of greenhouse gas concentrations, south polar ice will only melt to raise sea levels worldwide by about 15 cms. – Climate News Network

Food webs alter as warmer seas change colour

Reflected sunlight tells a story: one of deeper shading in an ever-warmer ocean. That is because climate change will also alter green growth in the high seas.

LONDON, 11 February, 2019 – The Blue Planet is to get a little bluer as the world warms and climates change. Where the seas turn green, expect an even deeper verdant tint, new research suggests.

Since humans began increasing the levels of greenhouse gases in the atmosphere – by burning the fossil fuels that have provided the energy for both economic growth and a population explosion – the oceans have warmed in ways that affect marine life. They have grown ever more acidic, in ways that affect coral growth and fish behaviour.

But when US and British scientists tested a model of ocean physics, biogeochemistry and ecosystems – intending to simulate changes in the populations of marine phytoplankton or algae – they also incorporated some of the ocean’s optical properties. Since green plants photosynthesise, they absorb sunlight, and change reflectivity.

And, as mariners have known for centuries, the blue ocean is blue because levels of marine life in the warmer mid-ocean waters are very low.

“There will be a noticeable difference in the colour of 50% of the ocean by the end of the 21st century. It could be potentially quite serious”

The researchers tweaked their simulation to see what the world would look like in 2100 if humanity carried on burning fossil fuels on the notorious business-as-usual scenario and took global average temperatures up to 3°C above historic levels.

And they found that higher temperatures would alter the global palette. More than half of the world’s oceans would intensify in colour. The subtropics would become even more blue, and the oceans that sweep around the poles would become an even deeper green, they report in the journal Nature Communications.

“The models suggest the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and the poles,” said Stephanie Dutkiewicz, of the Massachusetts Institute of Technology, who led the research

Wider effects.

“That basic pattern will still be there. But it will be enough different that it will affect the rest of the food web that phytoplankton supports.”

The clearer the water, the bluer the reflection of the sunlight. From space, the world looks blue. Waters rich in phytoplankton are by definition rich too in chlorophyll that absorbs blue wavelengths and reflects a green tint. But changes in chlorophyll colouring, observed over the decades from satellite monitoring, can be affected by natural climate cycles and shifts in nutrient supply.

The researchers were looking for a more complete model of the wavelengths of visible light that are absorbed, scattered or reflected by living things. They devised one, and tested their new model against satellite evidence so far. When they found agreement with the past, they had also found yet another way to read the future

Explaining ecosystem change.

They tuned their simulated planet to the 3°C warming that seems inevitable unless humans rapidly shift from fossil fuels to renewable energy sources, to discover that wavelengths of light around the blue-green spectrum shifted the fastest. The shifts in colour could tell a story of altered ecosystems.

“The nice thing about this model is that we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change,” Dr Dutkiewicz said.

“There will be a noticeable difference in the colour of 50% of the ocean by the end of the 21st century. It could be potentially quite serious..

“Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, they will also change the types of food webs they can support.” – Climate News Network

Reflected sunlight tells a story: one of deeper shading in an ever-warmer ocean. That is because climate change will also alter green growth in the high seas.

LONDON, 11 February, 2019 – The Blue Planet is to get a little bluer as the world warms and climates change. Where the seas turn green, expect an even deeper verdant tint, new research suggests.

Since humans began increasing the levels of greenhouse gases in the atmosphere – by burning the fossil fuels that have provided the energy for both economic growth and a population explosion – the oceans have warmed in ways that affect marine life. They have grown ever more acidic, in ways that affect coral growth and fish behaviour.

But when US and British scientists tested a model of ocean physics, biogeochemistry and ecosystems – intending to simulate changes in the populations of marine phytoplankton or algae – they also incorporated some of the ocean’s optical properties. Since green plants photosynthesise, they absorb sunlight, and change reflectivity.

And, as mariners have known for centuries, the blue ocean is blue because levels of marine life in the warmer mid-ocean waters are very low.

“There will be a noticeable difference in the colour of 50% of the ocean by the end of the 21st century. It could be potentially quite serious”

The researchers tweaked their simulation to see what the world would look like in 2100 if humanity carried on burning fossil fuels on the notorious business-as-usual scenario and took global average temperatures up to 3°C above historic levels.

And they found that higher temperatures would alter the global palette. More than half of the world’s oceans would intensify in colour. The subtropics would become even more blue, and the oceans that sweep around the poles would become an even deeper green, they report in the journal Nature Communications.

“The models suggest the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and the poles,” said Stephanie Dutkiewicz, of the Massachusetts Institute of Technology, who led the research

Wider effects.

“That basic pattern will still be there. But it will be enough different that it will affect the rest of the food web that phytoplankton supports.”

The clearer the water, the bluer the reflection of the sunlight. From space, the world looks blue. Waters rich in phytoplankton are by definition rich too in chlorophyll that absorbs blue wavelengths and reflects a green tint. But changes in chlorophyll colouring, observed over the decades from satellite monitoring, can be affected by natural climate cycles and shifts in nutrient supply.

The researchers were looking for a more complete model of the wavelengths of visible light that are absorbed, scattered or reflected by living things. They devised one, and tested their new model against satellite evidence so far. When they found agreement with the past, they had also found yet another way to read the future

Explaining ecosystem change.

They tuned their simulated planet to the 3°C warming that seems inevitable unless humans rapidly shift from fossil fuels to renewable energy sources, to discover that wavelengths of light around the blue-green spectrum shifted the fastest. The shifts in colour could tell a story of altered ecosystems.

“The nice thing about this model is that we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change,” Dr Dutkiewicz said.

“There will be a noticeable difference in the colour of 50% of the ocean by the end of the 21st century. It could be potentially quite serious..

“Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, they will also change the types of food webs they can support.” – Climate News Network

Whales’ appetite for plastics yawns wide

Polluting fragments and fibres get everywhere. Whales’ appetite for plastics shows how that includes the living tissue of some of the biggest sea creatures.

LONDON, 6 February, 2019 − There seem to be few limits to whales’ appetite for plastics. Scientists who checked the stomachs and intestines of 50 whales, dolphins and seals found stranded and dead on British coasts have identified plastic particles ingested by every one of them.

So far the researchers make no link between what now seems ubiquitous plastic pollution of the seas and the health of the animals – the numbers in each were tiny – but the find is yet another indicator of the steady degradation of the planet’s biggest natural habitat by just one terrestrial species with a lately-acquired addiction to fossil fuels.

A small fraction of the world’s oil, coal and natural gas output is turned into plastics or organic polymers with versatile and enduring properties, and four-fifths of the particles were identified as synthetic fibres from clothes, fishing nets and toothbrushes: the remainder may have come from food packaging and plastic containers.

“It’s shocking – but not surprising – that every animal had ingested microplastics,” said Sarah Nelms of the University of Exeter and the Plymouth Marine Laboratory, who led the study.

“The number of particles in each animal was relatively low (average of 5.5 particles per animal) suggesting they eventually pass through the digestive system, or are regurgitated. We don’t yet know what effects the microplastics, or the chemicals on and in them, might have on marine mammals.”

“Over the years we have found microplastic in nearly all the species of marine animals we have looked at”

The find was not surprising because in the last few years researchers have repeatedly established that in the century since the first synthesis of artificial polymer materials, colossal quantities have ended up in the oceans in ever-tinier particles: they have been found in the high Arctic, in every litre of sampled seawater, in coral reefs and in polar bears.

The scientists write in the journal Scientific Reports that they found at least one microplastic particle in every animal they examined, in either stomach or intestine.

Altogether, in 10 species – the Atlantic white-sided dolphin, the bottlenose, common, striped, white-beaked and Risso’s dolphins, the grey seal, the harbour seal, the harbour porpoise and the pygmy sperm whale − they found 273 particles, and 261 of these were smaller than 5mm. Most were fibres, ranging in size from 2cms to 0.1mm; 16% were fragments. At least 26 marine mammals are known to use British waters.

Colossal quantities of microplastics get into the sea from a variety of sources. Rain washes away fragments of tyres and paint; debris gets spilled during transportation; microbeads get washed out of fibres and cosmetics; large objects get abraded, crushed and fragmented.

Effects unknown

The smaller the size, the easier it is for the particles to be taken up by small crustaceans called copepods, shellfish, fish, seabirds and the bigger sea creatures and the marine mammals at the top of the food chain.

“Over the years we have found microplastic in nearly all the species of marine animals we have looked at; from tiny zooplankton at the base of the marine food web to fish larvae, turtles and now dolphins, seals and whales,” said Pennie Lindeque, who heads the marine plastics research group at Plymouth Marine Laboratory.

“We don’t yet know the effects of these particles on marine mammals. Their small size means they may easily be expelled, but while microplastics are unlikely to be the main threat to these species, we are still concerned by the impact of the bacteria, viruses and contaminants carried on the plastic.

“This study provides more evidence that we all need to help reduce the amount of plastic waste released to our seas.” − Climate News Network

Polluting fragments and fibres get everywhere. Whales’ appetite for plastics shows how that includes the living tissue of some of the biggest sea creatures.

LONDON, 6 February, 2019 − There seem to be few limits to whales’ appetite for plastics. Scientists who checked the stomachs and intestines of 50 whales, dolphins and seals found stranded and dead on British coasts have identified plastic particles ingested by every one of them.

So far the researchers make no link between what now seems ubiquitous plastic pollution of the seas and the health of the animals – the numbers in each were tiny – but the find is yet another indicator of the steady degradation of the planet’s biggest natural habitat by just one terrestrial species with a lately-acquired addiction to fossil fuels.

A small fraction of the world’s oil, coal and natural gas output is turned into plastics or organic polymers with versatile and enduring properties, and four-fifths of the particles were identified as synthetic fibres from clothes, fishing nets and toothbrushes: the remainder may have come from food packaging and plastic containers.

“It’s shocking – but not surprising – that every animal had ingested microplastics,” said Sarah Nelms of the University of Exeter and the Plymouth Marine Laboratory, who led the study.

“The number of particles in each animal was relatively low (average of 5.5 particles per animal) suggesting they eventually pass through the digestive system, or are regurgitated. We don’t yet know what effects the microplastics, or the chemicals on and in them, might have on marine mammals.”

“Over the years we have found microplastic in nearly all the species of marine animals we have looked at”

The find was not surprising because in the last few years researchers have repeatedly established that in the century since the first synthesis of artificial polymer materials, colossal quantities have ended up in the oceans in ever-tinier particles: they have been found in the high Arctic, in every litre of sampled seawater, in coral reefs and in polar bears.

The scientists write in the journal Scientific Reports that they found at least one microplastic particle in every animal they examined, in either stomach or intestine.

Altogether, in 10 species – the Atlantic white-sided dolphin, the bottlenose, common, striped, white-beaked and Risso’s dolphins, the grey seal, the harbour seal, the harbour porpoise and the pygmy sperm whale − they found 273 particles, and 261 of these were smaller than 5mm. Most were fibres, ranging in size from 2cms to 0.1mm; 16% were fragments. At least 26 marine mammals are known to use British waters.

Colossal quantities of microplastics get into the sea from a variety of sources. Rain washes away fragments of tyres and paint; debris gets spilled during transportation; microbeads get washed out of fibres and cosmetics; large objects get abraded, crushed and fragmented.

Effects unknown

The smaller the size, the easier it is for the particles to be taken up by small crustaceans called copepods, shellfish, fish, seabirds and the bigger sea creatures and the marine mammals at the top of the food chain.

“Over the years we have found microplastic in nearly all the species of marine animals we have looked at; from tiny zooplankton at the base of the marine food web to fish larvae, turtles and now dolphins, seals and whales,” said Pennie Lindeque, who heads the marine plastics research group at Plymouth Marine Laboratory.

“We don’t yet know the effects of these particles on marine mammals. Their small size means they may easily be expelled, but while microplastics are unlikely to be the main threat to these species, we are still concerned by the impact of the bacteria, viruses and contaminants carried on the plastic.

“This study provides more evidence that we all need to help reduce the amount of plastic waste released to our seas.” − Climate News Network

Food shocks increase as world warms

Heat extremes harm harvests. So do floods, drought and high winds. Climate change spurs food shocks that threaten the supper table.

LONDON, 1 February, 2019 − More than ever, the world’s ways of keeping hunger at bay are taking a pounding as food shocks become more frequent. Potatoes are being baked in heat waves. Corn is being parched by drought. Fruit is being bitten by frost.

And a long-term study suggests that for the world’s farmers and graziers, fishing crews and fish farmers, things will get worse as the world warms. Australian and US scientists report in the journal Nature Sustainability that they examined the incidence of what they call “food shocks” across 134 nations over a period of 53 years.

They found that some regions and some kinds of farming have suffered worse than others; that food production is vulnerable to volatile climate and weather changes; and that the dangers are increasing with time.

The researchers looked at cases of dramatic crop failure, harvest loss and fishing fleet failures between 1961 and 2013, as recorded by the UN Food and Agriculture Organisation and other sources, and then mapped shock frequency and co-occurrence.

In their database of 741 available time-series of food production, they found 226 cases of food shock: dramatic interruption of supply.

Hunger increases

Agriculture and livestock emerged as slightly more vulnerable to shock than fisheries and aquaculture. South Asia suffered most from crop damage or loss; the Caribbean for livestock, and Eastern Europe for fisheries; some of these regions were hard hit in more than one sector.

“The frequency of shocks has increased across all sectors at a global scale,” the authors report. “Increasing shock frequency is a food security concern in itself. Conflict-related shocks across sub-Saharan Africa and the Middle East since 2010, combined with adverse climate conditions, are responsible for the first uptick in global hunger in recent times.”

More than half of all shocks to food production were climate-related, and drought was the biggest factor. Extreme weather accounted for a quarter of shocks to livestock, and disease outbreaks another 10%, but the biggest single factor for pastoral farmers arose from geopolitical conflict and other crises.

Fisheries seemed better protected, and the worst shocks to fish landings could be traced to overfishing. Disruption to fish farming – a relatively new form of food production – has grown at a faster rate and to a higher level than in any other sector.

Climate scientists and agricultural researchers have been warning for years that food security is at hazard from global warming and climate change, both driven by profligate human use of fossil fuels and unthinking destruction of forests and natural grasslands and wetlands.

“While the number of food shocks fluctuates from year to year, the long-term trend shows they are happening more often”

Heat extremes can harm cereal yields almost anywhere, but Africa and South-east Asia are particularly at risk from changes in precipitation patterns.

The latest study is a reminder that, in some ways, the future has already arrived: the forewarned rise in climate extremes such as flood, heat and drought can be detected in the annual harvest tally around the globe.

And although a high percentage of the food supply damage can be linked to social conflict or political stress, climate change seems increasingly to be a factor in civil and international violence.

A new study for the UN security council – co-incidentally released on the same day – confirms the picture. Hunger and conflict are in a persistent and deadly partnership that threatens millions.

Mass famine

The number of food shocks fluctuates from year to year, the Nature Sustainability authors say. That is because factors such as social conflict and climate change can in synergy create a number of shocks across different sectors at different times. At least 22 of the 134 nations experienced shocks in many sectors over the same five-year time period.

In some cases, these shocks ended with more than just empty shelves. The collapse of the Soviet Union late in the last century removed some economic support from North Korea: subsequent floods precipitated a famine that killed 200,000 people.

Iraq’s invasion of Kuwait in 1991, and the subsequent Gulf War, devastated agricultural land and cost Kuwait’s commercial fishermen their livelihoods. Drought in Afghanistan in 2001 and 2002 decimated cereal yields, pastoralists lost fodder for their cattle and animal disease incidence soared.

“While the number of food shocks fluctuates from year to year, the long-term trend shows they are happening more often,” said Richard Cottrell of the University of Tasmania, who led the study.

“Globalised trade and the dependence of many countries on food imports mean that food shocks are a global problem, and the international community faces a significant challenge to build resilience.” − Climate News Network

Heat extremes harm harvests. So do floods, drought and high winds. Climate change spurs food shocks that threaten the supper table.

LONDON, 1 February, 2019 − More than ever, the world’s ways of keeping hunger at bay are taking a pounding as food shocks become more frequent. Potatoes are being baked in heat waves. Corn is being parched by drought. Fruit is being bitten by frost.

And a long-term study suggests that for the world’s farmers and graziers, fishing crews and fish farmers, things will get worse as the world warms. Australian and US scientists report in the journal Nature Sustainability that they examined the incidence of what they call “food shocks” across 134 nations over a period of 53 years.

They found that some regions and some kinds of farming have suffered worse than others; that food production is vulnerable to volatile climate and weather changes; and that the dangers are increasing with time.

The researchers looked at cases of dramatic crop failure, harvest loss and fishing fleet failures between 1961 and 2013, as recorded by the UN Food and Agriculture Organisation and other sources, and then mapped shock frequency and co-occurrence.

In their database of 741 available time-series of food production, they found 226 cases of food shock: dramatic interruption of supply.

Hunger increases

Agriculture and livestock emerged as slightly more vulnerable to shock than fisheries and aquaculture. South Asia suffered most from crop damage or loss; the Caribbean for livestock, and Eastern Europe for fisheries; some of these regions were hard hit in more than one sector.

“The frequency of shocks has increased across all sectors at a global scale,” the authors report. “Increasing shock frequency is a food security concern in itself. Conflict-related shocks across sub-Saharan Africa and the Middle East since 2010, combined with adverse climate conditions, are responsible for the first uptick in global hunger in recent times.”

More than half of all shocks to food production were climate-related, and drought was the biggest factor. Extreme weather accounted for a quarter of shocks to livestock, and disease outbreaks another 10%, but the biggest single factor for pastoral farmers arose from geopolitical conflict and other crises.

Fisheries seemed better protected, and the worst shocks to fish landings could be traced to overfishing. Disruption to fish farming – a relatively new form of food production – has grown at a faster rate and to a higher level than in any other sector.

Climate scientists and agricultural researchers have been warning for years that food security is at hazard from global warming and climate change, both driven by profligate human use of fossil fuels and unthinking destruction of forests and natural grasslands and wetlands.

“While the number of food shocks fluctuates from year to year, the long-term trend shows they are happening more often”

Heat extremes can harm cereal yields almost anywhere, but Africa and South-east Asia are particularly at risk from changes in precipitation patterns.

The latest study is a reminder that, in some ways, the future has already arrived: the forewarned rise in climate extremes such as flood, heat and drought can be detected in the annual harvest tally around the globe.

And although a high percentage of the food supply damage can be linked to social conflict or political stress, climate change seems increasingly to be a factor in civil and international violence.

A new study for the UN security council – co-incidentally released on the same day – confirms the picture. Hunger and conflict are in a persistent and deadly partnership that threatens millions.

Mass famine

The number of food shocks fluctuates from year to year, the Nature Sustainability authors say. That is because factors such as social conflict and climate change can in synergy create a number of shocks across different sectors at different times. At least 22 of the 134 nations experienced shocks in many sectors over the same five-year time period.

In some cases, these shocks ended with more than just empty shelves. The collapse of the Soviet Union late in the last century removed some economic support from North Korea: subsequent floods precipitated a famine that killed 200,000 people.

Iraq’s invasion of Kuwait in 1991, and the subsequent Gulf War, devastated agricultural land and cost Kuwait’s commercial fishermen their livelihoods. Drought in Afghanistan in 2001 and 2002 decimated cereal yields, pastoralists lost fodder for their cattle and animal disease incidence soared.

“While the number of food shocks fluctuates from year to year, the long-term trend shows they are happening more often,” said Richard Cottrell of the University of Tasmania, who led the study.

“Globalised trade and the dependence of many countries on food imports mean that food shocks are a global problem, and the international community faces a significant challenge to build resilience.” − Climate News Network

Ocean waves pack bigger and stronger punch

The ocean waves are now hitting harder than ever. As the world warms, they gain in energy, impact and height.

LONDON, 23 January, 2019 – As the world’s seas warm, the ocean waves are starting to pack more power. Spanish scientists monitoring the tropical Atlantic report that the waves today contain more energy than they did 70 years ago. Sea surface temperatures influence wind patterns, and the payoff is a wave with more impact.

What this means for marine creatures, mariners, meteorologists and the mayors of seaside cities is not yet certain. But it does mean that wave energy could join carbon dioxide atmospheric ratios, global sea level rise and global air temperatures as yet one more metric of overall global warming and climate change.

And Chinese scientists who have been calculating the heat absorbed by the oceans over the last 30 years have confirmed that in 2018 ocean temperatures reached record levels. Before that, 2017 was the hottest oceanic year ever, followed by 2015, 2016 and 2014. Once again, the implications are uncertain: sea levels will rise with ocean temperatures.

“The new data … serve as an additional warning to both the government and the general public that we are experiencing inevitable global warming”

Researchers from the University of Cantabria in Santander, Spain report in the journal Nature Communications that waves have been growing in height in recent decades, and satellite studies confirmed a change of about 1% every four years from 1985 to 2008.

But their research focused on changes in wave energy, important because of the effect wave behaviour has on estuaries, shoals, beaches, dunes, headlands, harbours and sea defences. They examined data from 1948 to 2017 to trace a small but measurable increase in wave energy with the decades.

“For the first time, we have identified a global signal of the effect of global warming in wave climate,” said Borja Reguero, of Cantabria’s environmental hydraulics institute, who is also at the University of California Santa Cruz.

“In fact, wave power has increased globally by 0.4% per year since 1948, and this increase is correlated with the increasing sea surface temperatures, both globally and by ocean regions.”

A hundred million Hiroshimas

Chinese and US researchers recently calculated the heat absorbed by the oceans as ever higher ratios of greenhouse gases – the product of fossil fuel combustion and other human action – are added to the planet’s atmosphere.

Members of the same team report in the journal Advances in Atmospheric Sciences that between 2017 and 2018 alone, the oceans must have absorbed an extra quantity of heat equivalent to 388 times the total electricity generation in China, and – to choose another and more vivid unit of measurement – around 100 million times the heat released by the atomic bomb that in August 1945 destroyed the Japanese city of Hiroshima.

“The new data, together with a rich body of literature, serve as an additional warning to both the government and the general public that we are experiencing inevitable global warming,” said Lijing Cheng of the Chinese Academy of Sciences, the lead author of the report.

“The ocean and global warming have already taken place and caused serious damage and losses to both the economy and society.” – Climate News Network

The ocean waves are now hitting harder than ever. As the world warms, they gain in energy, impact and height.

LONDON, 23 January, 2019 – As the world’s seas warm, the ocean waves are starting to pack more power. Spanish scientists monitoring the tropical Atlantic report that the waves today contain more energy than they did 70 years ago. Sea surface temperatures influence wind patterns, and the payoff is a wave with more impact.

What this means for marine creatures, mariners, meteorologists and the mayors of seaside cities is not yet certain. But it does mean that wave energy could join carbon dioxide atmospheric ratios, global sea level rise and global air temperatures as yet one more metric of overall global warming and climate change.

And Chinese scientists who have been calculating the heat absorbed by the oceans over the last 30 years have confirmed that in 2018 ocean temperatures reached record levels. Before that, 2017 was the hottest oceanic year ever, followed by 2015, 2016 and 2014. Once again, the implications are uncertain: sea levels will rise with ocean temperatures.

“The new data … serve as an additional warning to both the government and the general public that we are experiencing inevitable global warming”

Researchers from the University of Cantabria in Santander, Spain report in the journal Nature Communications that waves have been growing in height in recent decades, and satellite studies confirmed a change of about 1% every four years from 1985 to 2008.

But their research focused on changes in wave energy, important because of the effect wave behaviour has on estuaries, shoals, beaches, dunes, headlands, harbours and sea defences. They examined data from 1948 to 2017 to trace a small but measurable increase in wave energy with the decades.

“For the first time, we have identified a global signal of the effect of global warming in wave climate,” said Borja Reguero, of Cantabria’s environmental hydraulics institute, who is also at the University of California Santa Cruz.

“In fact, wave power has increased globally by 0.4% per year since 1948, and this increase is correlated with the increasing sea surface temperatures, both globally and by ocean regions.”

A hundred million Hiroshimas

Chinese and US researchers recently calculated the heat absorbed by the oceans as ever higher ratios of greenhouse gases – the product of fossil fuel combustion and other human action – are added to the planet’s atmosphere.

Members of the same team report in the journal Advances in Atmospheric Sciences that between 2017 and 2018 alone, the oceans must have absorbed an extra quantity of heat equivalent to 388 times the total electricity generation in China, and – to choose another and more vivid unit of measurement – around 100 million times the heat released by the atomic bomb that in August 1945 destroyed the Japanese city of Hiroshima.

“The new data, together with a rich body of literature, serve as an additional warning to both the government and the general public that we are experiencing inevitable global warming,” said Lijing Cheng of the Chinese Academy of Sciences, the lead author of the report.

“The ocean and global warming have already taken place and caused serious damage and losses to both the economy and society.” – Climate News Network

Warming may mean sea levels 30 cms higher

Warmer oceans mean higher tides, bigger storm surges and heavier rainstorms. With ocean temperatures rising ever faster, sea levels 30 cms higher are possible by 2100.

LONDON, 14 January, 2019 − The world’s oceans are warming increasingly fast. The planet could face sea levels 30 cms higher in 80 years.

While 2018 was probably only the fourth warmest year for global surface temperatures, it is likely to have been the hottest year ever for the oceans. The previous such year was 2017, and before that 2016.

And if global warming follows the pattern predicted by computer simulations, then at present rates the extra temperature of the oceans will cause a thermal expansion – warm water is always less dense than cold water – by 30 centimetres by the end of the century.

That is 30cms of sea level rise on top of all the extra rising sea water delivered by melting ice caps and glaciers on the world’s continents.

“The need to slow or stop the rates of climate change and prepare for the expected impacts is increasingly evident”

The planet is 71% ocean and the clear blue water absorbs an estimated 93% of all the excess heat trapped by the greenhouse gases emitted by humans as they burn fossil fuels to power the global economy.

And a quartet of scientists from China and the US calculate that if the world goes on burning fossil fuels under the notorious business-as-usual scenario, then by the end of the century the top 2,000 metres of the high seas will have warmed by 0.78°C, causing 30cms of sea level rise simply by ocean expansion.

These warmer waters, inevitably, will in turn and less directly accelerate the already increasingly rapid melting of Greenland’s glaciers and surface ice, and eat away at the floating ice shelves that for the moment slow the great glaciers of the Antarctic continent.

Warmer sea waters are linked to the propagation of hurricanes, typhoons or tropical cyclones; to ever heavier and more devastating rainstorms; and to prolonged droughts, heat waves and forest fires.

Oceans are indicator

“If you want to see where global warming is happening, look in our oceans. Ocean heating is a very important indicator of climate change, and we have robust evidence that it is warming more rapidly than we thought,” said Zeke Hausfather, of the Energy and Resources Group at the University of California, Berkeley, and a co-author of the study in the journal Science.

“While 2018 will be the fourth warmest year on record on the surface, it will most certainly be the warmest year on record in the oceans, as was 2017 and 2016 before that. The global warming signal is a lot easier to detect if it is changing in the oceans than on the surface.”

The research is based on readings from Project Argo, a fleet of nearly 4,000 floating robots that periodically dive to 2,000 metres depth to measure ocean temperatures, chemistry, salinity and so on. The latest predictions are backed up by other recent studies.

One has calculated the heat that must have been absorbed by the oceans over the last 150 years. Another has already confirmed the latest study’s other conclusion, that the so-called “hiatus” in global warming never really happened: the heat not registered in global average air temperatures was taken up by the oceans.

Heat uptake continues

Ocean temperatures matter to climate calculations. What happens to air temperatures can be affected briefly by any number of natural cycles. An El Niño event may make one year conspicuously warmer than the next; a sequence of explosive volcanic eruptions may darken the skies and, for a year or so, lower the global temperatures. But the vast body of water that defines the blue planet is largely impervious to brief surface changes.

And, the researchers calculate, it will go on absorbing heat. By 2100, once again under the business-as-usual scenario, the five great oceans could between them have warmed by a total of 2,020 zettajoules: a joule is a basic unit of energy, and one zettajoule adds up to a billion trillion joules.

“This level of warming,” the scientists say, “would have major impacts on ocean ecosystems and sea level rise through thermal expansion.” They identify, they say, a clear need to go on trying to refine climate models and to improve their observations of ocean change.

“In addition, the need to slow or stop the rates of climate change and prepare for the expected impacts is increasingly evident.” − Climate News Network

Warmer oceans mean higher tides, bigger storm surges and heavier rainstorms. With ocean temperatures rising ever faster, sea levels 30 cms higher are possible by 2100.

LONDON, 14 January, 2019 − The world’s oceans are warming increasingly fast. The planet could face sea levels 30 cms higher in 80 years.

While 2018 was probably only the fourth warmest year for global surface temperatures, it is likely to have been the hottest year ever for the oceans. The previous such year was 2017, and before that 2016.

And if global warming follows the pattern predicted by computer simulations, then at present rates the extra temperature of the oceans will cause a thermal expansion – warm water is always less dense than cold water – by 30 centimetres by the end of the century.

That is 30cms of sea level rise on top of all the extra rising sea water delivered by melting ice caps and glaciers on the world’s continents.

“The need to slow or stop the rates of climate change and prepare for the expected impacts is increasingly evident”

The planet is 71% ocean and the clear blue water absorbs an estimated 93% of all the excess heat trapped by the greenhouse gases emitted by humans as they burn fossil fuels to power the global economy.

And a quartet of scientists from China and the US calculate that if the world goes on burning fossil fuels under the notorious business-as-usual scenario, then by the end of the century the top 2,000 metres of the high seas will have warmed by 0.78°C, causing 30cms of sea level rise simply by ocean expansion.

These warmer waters, inevitably, will in turn and less directly accelerate the already increasingly rapid melting of Greenland’s glaciers and surface ice, and eat away at the floating ice shelves that for the moment slow the great glaciers of the Antarctic continent.

Warmer sea waters are linked to the propagation of hurricanes, typhoons or tropical cyclones; to ever heavier and more devastating rainstorms; and to prolonged droughts, heat waves and forest fires.

Oceans are indicator

“If you want to see where global warming is happening, look in our oceans. Ocean heating is a very important indicator of climate change, and we have robust evidence that it is warming more rapidly than we thought,” said Zeke Hausfather, of the Energy and Resources Group at the University of California, Berkeley, and a co-author of the study in the journal Science.

“While 2018 will be the fourth warmest year on record on the surface, it will most certainly be the warmest year on record in the oceans, as was 2017 and 2016 before that. The global warming signal is a lot easier to detect if it is changing in the oceans than on the surface.”

The research is based on readings from Project Argo, a fleet of nearly 4,000 floating robots that periodically dive to 2,000 metres depth to measure ocean temperatures, chemistry, salinity and so on. The latest predictions are backed up by other recent studies.

One has calculated the heat that must have been absorbed by the oceans over the last 150 years. Another has already confirmed the latest study’s other conclusion, that the so-called “hiatus” in global warming never really happened: the heat not registered in global average air temperatures was taken up by the oceans.

Heat uptake continues

Ocean temperatures matter to climate calculations. What happens to air temperatures can be affected briefly by any number of natural cycles. An El Niño event may make one year conspicuously warmer than the next; a sequence of explosive volcanic eruptions may darken the skies and, for a year or so, lower the global temperatures. But the vast body of water that defines the blue planet is largely impervious to brief surface changes.

And, the researchers calculate, it will go on absorbing heat. By 2100, once again under the business-as-usual scenario, the five great oceans could between them have warmed by a total of 2,020 zettajoules: a joule is a basic unit of energy, and one zettajoule adds up to a billion trillion joules.

“This level of warming,” the scientists say, “would have major impacts on ocean ecosystems and sea level rise through thermal expansion.” They identify, they say, a clear need to go on trying to refine climate models and to improve their observations of ocean change.

“In addition, the need to slow or stop the rates of climate change and prepare for the expected impacts is increasingly evident.” − Climate News Network

Ocean warming speeds vary with depth

The world’s oceans are a vast reservoir of heat, a slow register of natural climate change − and ocean warming speeds differ widely.

LONDON, 10 January, 2019 − Climate scientists who have found a new way to chart temperature change in the world’s seas over time say ocean warming speeds are much slower in deep water than on the surface.

Planet Earth is mostly ocean. Human-linked changes have started to raise global temperatures to what could be alarming levels and, as the thermometer rises, so will sea levels. So detailed understanding of temperature and ocean is vital. But two separate studies confirm that the connection is far from simple.

One study of the Atlantic confirms that in the last 150 years, the oceans have taken up 90% of the excess energy released by the combustion of fossil fuels to drive human economic growth and power − and to fuel potentially-catastrophic global warming and runaway climate change.

But what the oceans will actually do with that colossal burst of heat has yet to be fully explored. And a separate examination of the deep history of the Pacific Ocean confirms that change may be inexorable, but it is also very slow: the deeper parts of the Pacific are still registering the onset of the so-called “Little Ice Age” several centuries ago.

“These waters are so old and haven’t been near the surface in so long, they still ‘remember’ what was going on hundreds of years ago”

Both studies are reminders that oceanography is still a relatively new science and researchers still have a lot to learn about the fine detail of the ways in which temperature, atmosphere and ocean interact to affect climate over the world’s continents.

But repeated research has confirmed that the oceans are warming in response to human-triggered changes on land, that this warming presents several different kinds of hazard  to marine life, and that there is a link between overall ocean temperatures and the behaviour of the ocean’s currents, a link that plays out in dramatic shifts in regional climates.

So the rewards for a more precise understanding are considerable. But understanding starts with accurate and comprehensive data, and systematic measurement of ocean temperatures began only with the voyage of the British research ship HMS Challenger in 1871.

So Laure Zanna, a physicist at the University of Oxford and her colleagues, report in the Proceedings of the National Academy of Sciences that they deployed sophisticated mathematical techniques to calculate the heat uptake of the oceans and the way the blue planet has responded since 1871.

Huge heat uptake

Altogether, in the last 150 years, the deep waters have absorbed 436 zettajoules: a joule is the unit of energy required to deliver one watt for one second and a zettajoule is a number followed by 21 zeroes. This is an enormous amount of heat, roughly 1,000 times the energy consumed by 7 billion humans in the course of a year.

The researchers’ results so far show that roughly half the observed warming of the last 60 years – and the associated sea level rise – is linked to changes in ocean circulation. They were able to reconstruct two considerable bouts of warming, over the years 1920 to 1945 and between 1990 and 2015. What they have yet to do is sort out what this means for the behaviour of the oceans over the decades to come.

“The technique is only applicable to tracers like man-made carbon that are passively transported by ocean circulation,” Professor Zanna said. “However, heat does not behave in this manner as it affects circulation by changing the density of seawater. We were pleasantly surprised by how well the approach works. It opens up an exciting new way to study ocean warming in addition to using direct measurements.”

What the research also underlines is that the oceans have a long memory: so extensive and so deep are the five oceans that the surface waters may respond to 20th century greenhouse gas emissions while the deepest trenches contain water that last warmed more than 1,000 years ago in the reign of Charlemagne, the first Holy Roman Emperor.

Still adjusting

US oceanographers report in the journal Science that they matched predictions from computer models and modern data and ancient evidence with readings from the Challenger expedition to show that two kilometres under the waves, the Pacific Ocean is still adjusting to cooling that began with the onset of the Little Ice Age centuries ago.

Such studies count as basic research: as a way of testing techniques and establishing ground rules from which more discovery could follow. They also offer new ways to understand oceans as registers of climate change over long intervals.

“These waters are so old and haven’t been near the surface in so long, they still ‘remember’ what was going on hundreds of years ago when Europe experienced some of its coldest winters in history,” said Jake Gebbie, of the Woods Hole Oceanographic Institution.

“The close correspondence between prediction and observed trends gave us confidence that this is a real phenomenon.” − Climate News Network

The world’s oceans are a vast reservoir of heat, a slow register of natural climate change − and ocean warming speeds differ widely.

LONDON, 10 January, 2019 − Climate scientists who have found a new way to chart temperature change in the world’s seas over time say ocean warming speeds are much slower in deep water than on the surface.

Planet Earth is mostly ocean. Human-linked changes have started to raise global temperatures to what could be alarming levels and, as the thermometer rises, so will sea levels. So detailed understanding of temperature and ocean is vital. But two separate studies confirm that the connection is far from simple.

One study of the Atlantic confirms that in the last 150 years, the oceans have taken up 90% of the excess energy released by the combustion of fossil fuels to drive human economic growth and power − and to fuel potentially-catastrophic global warming and runaway climate change.

But what the oceans will actually do with that colossal burst of heat has yet to be fully explored. And a separate examination of the deep history of the Pacific Ocean confirms that change may be inexorable, but it is also very slow: the deeper parts of the Pacific are still registering the onset of the so-called “Little Ice Age” several centuries ago.

“These waters are so old and haven’t been near the surface in so long, they still ‘remember’ what was going on hundreds of years ago”

Both studies are reminders that oceanography is still a relatively new science and researchers still have a lot to learn about the fine detail of the ways in which temperature, atmosphere and ocean interact to affect climate over the world’s continents.

But repeated research has confirmed that the oceans are warming in response to human-triggered changes on land, that this warming presents several different kinds of hazard  to marine life, and that there is a link between overall ocean temperatures and the behaviour of the ocean’s currents, a link that plays out in dramatic shifts in regional climates.

So the rewards for a more precise understanding are considerable. But understanding starts with accurate and comprehensive data, and systematic measurement of ocean temperatures began only with the voyage of the British research ship HMS Challenger in 1871.

So Laure Zanna, a physicist at the University of Oxford and her colleagues, report in the Proceedings of the National Academy of Sciences that they deployed sophisticated mathematical techniques to calculate the heat uptake of the oceans and the way the blue planet has responded since 1871.

Huge heat uptake

Altogether, in the last 150 years, the deep waters have absorbed 436 zettajoules: a joule is the unit of energy required to deliver one watt for one second and a zettajoule is a number followed by 21 zeroes. This is an enormous amount of heat, roughly 1,000 times the energy consumed by 7 billion humans in the course of a year.

The researchers’ results so far show that roughly half the observed warming of the last 60 years – and the associated sea level rise – is linked to changes in ocean circulation. They were able to reconstruct two considerable bouts of warming, over the years 1920 to 1945 and between 1990 and 2015. What they have yet to do is sort out what this means for the behaviour of the oceans over the decades to come.

“The technique is only applicable to tracers like man-made carbon that are passively transported by ocean circulation,” Professor Zanna said. “However, heat does not behave in this manner as it affects circulation by changing the density of seawater. We were pleasantly surprised by how well the approach works. It opens up an exciting new way to study ocean warming in addition to using direct measurements.”

What the research also underlines is that the oceans have a long memory: so extensive and so deep are the five oceans that the surface waters may respond to 20th century greenhouse gas emissions while the deepest trenches contain water that last warmed more than 1,000 years ago in the reign of Charlemagne, the first Holy Roman Emperor.

Still adjusting

US oceanographers report in the journal Science that they matched predictions from computer models and modern data and ancient evidence with readings from the Challenger expedition to show that two kilometres under the waves, the Pacific Ocean is still adjusting to cooling that began with the onset of the Little Ice Age centuries ago.

Such studies count as basic research: as a way of testing techniques and establishing ground rules from which more discovery could follow. They also offer new ways to understand oceans as registers of climate change over long intervals.

“These waters are so old and haven’t been near the surface in so long, they still ‘remember’ what was going on hundreds of years ago when Europe experienced some of its coldest winters in history,” said Jake Gebbie, of the Woods Hole Oceanographic Institution.

“The close correspondence between prediction and observed trends gave us confidence that this is a real phenomenon.” − Climate News Network

Human horde leaves little room for nature

Our species’ planetary advance has been inexorable. The human horde means under a quarter of the world’s land surface now counts as wilderness.

LONDON, 8 November, 2018 – Only 23% of the planet’s habitable terrestrial surface now remains as undisturbed wilderness, thanks to the spread of the human horde.

A century ago, as the human population explosion began, 85% of the world was undisturbed living space for all the other species. Yet between 1993 and 2009 – in the years that followed hard on the first global summit to consider the state of the planetary environment – an aggregation of areas of wilderness larger than India was delivered over to human exploitation, scientists warn in the journal Nature.

“These results are nothing short of a horror story for the planet’s last wild places,” said James Watson, a scientist at the University of Queensland and with the Wildlife Conservation Society.

“The loss of wilderness must be treated in the same way we treat extinction. There is no reversing, once the first cut enters. The decision is forever.”

Ocean impact

Professor Watson and colleagues argued in August that humans had in some way poisoned, polluted, exploited or disturbed almost all the planet’s oceans: only 13% could now be classified as undisturbed.

Now he and others have addressed the state of the wild terrestrial soils and rocks. Take Antarctica – essentially uninhabited, and with no terrestrial wildlife – out of the equation, and the scale of planetary devastation becomes more stark: humans have now left their mark on 77% of the world’s living space.

And the remaining wilderness is unevenly distributed: just 20 nations hold or govern 94% of the remaining marine and terrestrial wilderness areas. Russia, Canada, Australia, the US and Brazil host 70% of these unspoiled spaces.

Professor Watson and many others have repeatedly argued that humankind continues to put the world’s wildlife at risk. A new study by the World Wide Fund for Nature highlights the scale of destruction, but repeated surveys by teams of researchers on all continents have pointed up the same danger.

The combination of human intrusion into the wilderness and the spectre of climate change is a disaster for the 10 million or so species, most of them as yet unidentified, with which humans share the planet.

“These results are nothing short of a horror story for the planet’s last wild places”

“A century ago, only 15% of the Earth’s surface was used by humans to grow crops and raise livestock,” Professor Watson said.

“Today, more than 77% of land – excluding Antarctica – and 87% of the ocean has been modified by the direct effects of human activities. It might be hard to believe, but between 1993 and 2009, an area of terrestrial wilderness larger than India – a staggering 3.3 million square kilometres – was lost to human settlement, farming, mining and other pressures.

“And in the ocean, the only regions that are free of industrial fishing, pollution and shipping are almost completely confined to the polar regions.” – Climate News Network

Our species’ planetary advance has been inexorable. The human horde means under a quarter of the world’s land surface now counts as wilderness.

LONDON, 8 November, 2018 – Only 23% of the planet’s habitable terrestrial surface now remains as undisturbed wilderness, thanks to the spread of the human horde.

A century ago, as the human population explosion began, 85% of the world was undisturbed living space for all the other species. Yet between 1993 and 2009 – in the years that followed hard on the first global summit to consider the state of the planetary environment – an aggregation of areas of wilderness larger than India was delivered over to human exploitation, scientists warn in the journal Nature.

“These results are nothing short of a horror story for the planet’s last wild places,” said James Watson, a scientist at the University of Queensland and with the Wildlife Conservation Society.

“The loss of wilderness must be treated in the same way we treat extinction. There is no reversing, once the first cut enters. The decision is forever.”

Ocean impact

Professor Watson and colleagues argued in August that humans had in some way poisoned, polluted, exploited or disturbed almost all the planet’s oceans: only 13% could now be classified as undisturbed.

Now he and others have addressed the state of the wild terrestrial soils and rocks. Take Antarctica – essentially uninhabited, and with no terrestrial wildlife – out of the equation, and the scale of planetary devastation becomes more stark: humans have now left their mark on 77% of the world’s living space.

And the remaining wilderness is unevenly distributed: just 20 nations hold or govern 94% of the remaining marine and terrestrial wilderness areas. Russia, Canada, Australia, the US and Brazil host 70% of these unspoiled spaces.

Professor Watson and many others have repeatedly argued that humankind continues to put the world’s wildlife at risk. A new study by the World Wide Fund for Nature highlights the scale of destruction, but repeated surveys by teams of researchers on all continents have pointed up the same danger.

The combination of human intrusion into the wilderness and the spectre of climate change is a disaster for the 10 million or so species, most of them as yet unidentified, with which humans share the planet.

“These results are nothing short of a horror story for the planet’s last wild places”

“A century ago, only 15% of the Earth’s surface was used by humans to grow crops and raise livestock,” Professor Watson said.

“Today, more than 77% of land – excluding Antarctica – and 87% of the ocean has been modified by the direct effects of human activities. It might be hard to believe, but between 1993 and 2009, an area of terrestrial wilderness larger than India – a staggering 3.3 million square kilometres – was lost to human settlement, farming, mining and other pressures.

“And in the ocean, the only regions that are free of industrial fishing, pollution and shipping are almost completely confined to the polar regions.” – Climate News Network