Tag Archives: Oceans

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

Human carbon emissions to rise in 2019

Here comes another dismal science forecast, with human carbon emissions due to rise this year. Forests may be unable to keep pace as global warming increases.

LONDON, 31 January, 2019 − Stand by for a year in which global warming can only get worse as human carbon emissions climb still further. British meteorologists warn that although 2018 broke all records for greenhouse gas emissions, 2019 will see even more carbon dioxide take up long-term residence in the planetary atmosphere.

And it will happen for two reasons, both of them nominally at least under human control. The overall release of carbon dioxide from power stations, factory chimneys, cement quarries, car exhausts and so on will continue to rise with fossil fuel combustion, even though there has been greater investment than ever in renewable resources such as wind and solar energy.

And those natural “sinks” that absorb extra carbon from the atmosphere and sequester it as living timber in the forests, or bones and shells in the oceans, are expected to under-perform.

This is largely because of natural cyclic variation in the tropical climate, but also partly because humans continue to degrade grasslands and fell or burn the forests that naturally absorb carbon dioxide from the atmosphere and return oxygen for the animal world to breathe.

Hawaii’s unique record

Climate scientists know what is going to happen because they can see the future already written in a unique 60-year-old cycle of data recorded high on a mountaintop in Hawaii, in the Pacific, far from any heavy industry or city pollution that might distort the local chemistry of the atmosphere.

“Since 1958, monitoring at the Mauna Loa observatory in Hawaii has registered around a 30% increase in the concentration of carbon dioxide in the atmosphere,” said Richard Betts, of the UK Met Office’s Hadley Centre.

“This is caused by emissions from fossil fuels, deforestation and cement production, and the increase would have been even larger if it were not for natural carbon sinks which soak up some of the excess CO2.

This year we expect these carbon sinks to be relatively weak, so the impact of record high human-caused emissions will be larger than last year.”

“Deforestation in the Brazilian Amazon increased to around 8,000 square kilometres in 2018, equivalent to losing a football pitch of forest every 80 seconds”

At the heart of the diagnosis is the increasing understanding of the role of the world’s great oceans in managing planetary weather patterns.

A year ago the tropical Pacific was relatively cool, rainfall increased and land-based ecosystems flourished, soaking up atmospheric carbon. In a relatively warm cycle, many regions become warmer and drier, which in turn limits plant growth.

Carbon dioxide ratios in the global atmosphere for most of human history, until the Industrial Revolution and the arrival of the steam age and the internal combustion engine, oscillated at around 280 parts per million (ppm). In the last decade, the ratio reached 400 ppm, and in 2018 peaked at 414.7 ppm in May, before beginning to fall in the northern hemisphere growing season, to rise again in September.

El Niño distortion

Overall, the average for 2018 was 411 ppm, with an uncertainty factor of 0.6 ppm. In 2019, the average is likely to be 2.75 ppm higher still. This would be one of the largest annual rises on record.

The rises in 2015-2016 and in 1997-1998 were higher, but these years’ readings were distorted by the arrival of a dramatic but natural Pacific warming called El Niño, always associated with a sudden and often damaging shift in regional climate patterns far away.

Climate scientists have continued to hope for a global response to such predictions: these are the people who are professionally most aware of the big picture of global change.

Julienne Stroeve of University College London called the news “discouraging, for sure. Last year the extra CO2 was equivalent to melting about 110,000 square kilometres of Arctic Sea ice, or roughly three times the area of Switzerland. Sea ice loss is directly tied to increases in atmospheric CO2.”

Damage to forests

And Jos Barlow, of Lancaster University’s Environment Centre, warned that forest clearance in the tropics continued as a hazard.

Deforestation in the Brazilian Amazon increased to around 8,000 square kilometres in 2018, which is equivalent to losing a football pitch of forest every 80 seconds. This alone would result in CO2 emissions that exceed those of the UK over the same time period.”

Professor Betts called the Mauna Loa record of atmospheric carbon dioxide a “thing of beauty” and a stark reminder of human interference with the planetary climate.

“Looking at the monthly figures, it’s as if you can see the planet ‘breathing’ as the levels of carbon dioxide fall and rise with the seasonal cycle of plant growth and decay in the northern hemisphere. But each year’s CO2 is higher than the last, and this will keep happening until humans stop adding CO2 to the atmosphere.” − Climate News Network

Here comes another dismal science forecast, with human carbon emissions due to rise this year. Forests may be unable to keep pace as global warming increases.

LONDON, 31 January, 2019 − Stand by for a year in which global warming can only get worse as human carbon emissions climb still further. British meteorologists warn that although 2018 broke all records for greenhouse gas emissions, 2019 will see even more carbon dioxide take up long-term residence in the planetary atmosphere.

And it will happen for two reasons, both of them nominally at least under human control. The overall release of carbon dioxide from power stations, factory chimneys, cement quarries, car exhausts and so on will continue to rise with fossil fuel combustion, even though there has been greater investment than ever in renewable resources such as wind and solar energy.

And those natural “sinks” that absorb extra carbon from the atmosphere and sequester it as living timber in the forests, or bones and shells in the oceans, are expected to under-perform.

This is largely because of natural cyclic variation in the tropical climate, but also partly because humans continue to degrade grasslands and fell or burn the forests that naturally absorb carbon dioxide from the atmosphere and return oxygen for the animal world to breathe.

Hawaii’s unique record

Climate scientists know what is going to happen because they can see the future already written in a unique 60-year-old cycle of data recorded high on a mountaintop in Hawaii, in the Pacific, far from any heavy industry or city pollution that might distort the local chemistry of the atmosphere.

“Since 1958, monitoring at the Mauna Loa observatory in Hawaii has registered around a 30% increase in the concentration of carbon dioxide in the atmosphere,” said Richard Betts, of the UK Met Office’s Hadley Centre.

“This is caused by emissions from fossil fuels, deforestation and cement production, and the increase would have been even larger if it were not for natural carbon sinks which soak up some of the excess CO2.

This year we expect these carbon sinks to be relatively weak, so the impact of record high human-caused emissions will be larger than last year.”

“Deforestation in the Brazilian Amazon increased to around 8,000 square kilometres in 2018, equivalent to losing a football pitch of forest every 80 seconds”

At the heart of the diagnosis is the increasing understanding of the role of the world’s great oceans in managing planetary weather patterns.

A year ago the tropical Pacific was relatively cool, rainfall increased and land-based ecosystems flourished, soaking up atmospheric carbon. In a relatively warm cycle, many regions become warmer and drier, which in turn limits plant growth.

Carbon dioxide ratios in the global atmosphere for most of human history, until the Industrial Revolution and the arrival of the steam age and the internal combustion engine, oscillated at around 280 parts per million (ppm). In the last decade, the ratio reached 400 ppm, and in 2018 peaked at 414.7 ppm in May, before beginning to fall in the northern hemisphere growing season, to rise again in September.

El Niño distortion

Overall, the average for 2018 was 411 ppm, with an uncertainty factor of 0.6 ppm. In 2019, the average is likely to be 2.75 ppm higher still. This would be one of the largest annual rises on record.

The rises in 2015-2016 and in 1997-1998 were higher, but these years’ readings were distorted by the arrival of a dramatic but natural Pacific warming called El Niño, always associated with a sudden and often damaging shift in regional climate patterns far away.

Climate scientists have continued to hope for a global response to such predictions: these are the people who are professionally most aware of the big picture of global change.

Julienne Stroeve of University College London called the news “discouraging, for sure. Last year the extra CO2 was equivalent to melting about 110,000 square kilometres of Arctic Sea ice, or roughly three times the area of Switzerland. Sea ice loss is directly tied to increases in atmospheric CO2.”

Damage to forests

And Jos Barlow, of Lancaster University’s Environment Centre, warned that forest clearance in the tropics continued as a hazard.

Deforestation in the Brazilian Amazon increased to around 8,000 square kilometres in 2018, which is equivalent to losing a football pitch of forest every 80 seconds. This alone would result in CO2 emissions that exceed those of the UK over the same time period.”

Professor Betts called the Mauna Loa record of atmospheric carbon dioxide a “thing of beauty” and a stark reminder of human interference with the planetary climate.

“Looking at the monthly figures, it’s as if you can see the planet ‘breathing’ as the levels of carbon dioxide fall and rise with the seasonal cycle of plant growth and decay in the northern hemisphere. But each year’s CO2 is higher than the last, and this will keep happening until humans stop adding CO2 to the atmosphere.” − 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

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

Ocean warming may be faster than thought

Science knows that ocean warming is occurring. A big challenge now is to work out how quickly the temperature is rising.

LONDON, 7 November, 2018 – The seas are getting hotter – and researchers have thought again about just how much faster ocean warming is happening. They believe that in the last 25 years the oceans have absorbed at least 60% more heat than previous global estimates by the UN’s Intergovernmental Panel on Climate Change (IPCC) had considered.

And they calculate this heat as the equivalent to 150 times the annual human electricity generation in any one year.

“Imagine if the ocean was only 30 feet (10m) deep,” said Laure Resplandy, a researcher at the Princeton Environment Institute in the US. “Our data show that it would have warmed by 6.5°C every decade since 1991. In comparison, the estimate of the last IPCC assessment report would correspond to a warming of only 4°C every decade.”

The oceans cover 70% of the Blue Planet, but take up about 90% of all the excess energy produced as the Earth warms. If scientists can put a precise figure to this energy, then they can make more precise guesses about the surface warming to come, as humans continue to burn fossil fuels, release greenhouse gases such as carbon dioxide into the atmosphere, and drive up the planetary thermometer.

“There will have to be an even more drastic shutdown of fossil fuel investment and an even faster switch to renewable sources of energy”

At the academic level, this is the search for a factor known to climate researchers as climate sensitivity: the way the world responds to ever-increasing ratios of greenhouse gas in the atmosphere.

At the human level, this plays out as ever-greater extremes of heat, drought and rainfall, with ever-higher risks of catastrophic storm or flood, or harvest failure, and ever-higher tallies of human suffering.

Comprehensive global measurements of ocean temperature date only from 2007 and the network of robot sensors that deliver continuous data about the top half of the ocean basins.

Dr Resplandy and her colleagues report in the journal Nature that they used a sophisticated approach based on very high-precision measurements of levels of oxygen and carbon dioxide in the air.

Gases released

Both gases are soluble, and the oceans are becoming more acidic as the seas absorb ever-greater levels of carbon dioxide. But as seas warm, they also become less able to hold their dissolved gases, and release them into the atmosphere.

This simple consequence of atmospheric physics meant that the researchers could use what they call “atmospheric potential oxygen” to arrive at a new way of measuring the heat the oceans must have absorbed over time.

They used the standard unit of energy: the joule. Their new budget for heat absorbed each year between 1991 and 2016 is 13 zettajoules. That is a digit followed by 21 zeroes, the kind of magnitude astronomers tend to use.

That the oceans are warming is no surprise: this has been obvious from the crudest comparison of old naval data with modern surface checks, and for years some researchers argued that ever-higher ocean temperatures could account for the so-called slowdown in global warming in the first dozen years of this century.

Challenging achievement

The new finding counts first as an academic achievement: there is now a more precise thermometer reading, and new calculations can begin.

One of the researchers, Ralph Keeling of the Scripps Institution of Oceanography, said: “The result significantly increases the confidence we can place in estimates of ocean warming and therefore help reduce uncertainty in the climate sensitivity, particularly closing off the possibility of very low climate sensitivity.”

But the result also suggests that internationally agreed attempts to hold planetary warming to a maximum of just 2°C – and the world has already warmed by around 1°C in the last century – become more challenging.

It means that there will have to be an even more drastic shutdown of fossil fuel investment and an even faster switch to renewable sources of energy such as sun and wind power. – Climate News Network

Science knows that ocean warming is occurring. A big challenge now is to work out how quickly the temperature is rising.

LONDON, 7 November, 2018 – The seas are getting hotter – and researchers have thought again about just how much faster ocean warming is happening. They believe that in the last 25 years the oceans have absorbed at least 60% more heat than previous global estimates by the UN’s Intergovernmental Panel on Climate Change (IPCC) had considered.

And they calculate this heat as the equivalent to 150 times the annual human electricity generation in any one year.

“Imagine if the ocean was only 30 feet (10m) deep,” said Laure Resplandy, a researcher at the Princeton Environment Institute in the US. “Our data show that it would have warmed by 6.5°C every decade since 1991. In comparison, the estimate of the last IPCC assessment report would correspond to a warming of only 4°C every decade.”

The oceans cover 70% of the Blue Planet, but take up about 90% of all the excess energy produced as the Earth warms. If scientists can put a precise figure to this energy, then they can make more precise guesses about the surface warming to come, as humans continue to burn fossil fuels, release greenhouse gases such as carbon dioxide into the atmosphere, and drive up the planetary thermometer.

“There will have to be an even more drastic shutdown of fossil fuel investment and an even faster switch to renewable sources of energy”

At the academic level, this is the search for a factor known to climate researchers as climate sensitivity: the way the world responds to ever-increasing ratios of greenhouse gas in the atmosphere.

At the human level, this plays out as ever-greater extremes of heat, drought and rainfall, with ever-higher risks of catastrophic storm or flood, or harvest failure, and ever-higher tallies of human suffering.

Comprehensive global measurements of ocean temperature date only from 2007 and the network of robot sensors that deliver continuous data about the top half of the ocean basins.

Dr Resplandy and her colleagues report in the journal Nature that they used a sophisticated approach based on very high-precision measurements of levels of oxygen and carbon dioxide in the air.

Gases released

Both gases are soluble, and the oceans are becoming more acidic as the seas absorb ever-greater levels of carbon dioxide. But as seas warm, they also become less able to hold their dissolved gases, and release them into the atmosphere.

This simple consequence of atmospheric physics meant that the researchers could use what they call “atmospheric potential oxygen” to arrive at a new way of measuring the heat the oceans must have absorbed over time.

They used the standard unit of energy: the joule. Their new budget for heat absorbed each year between 1991 and 2016 is 13 zettajoules. That is a digit followed by 21 zeroes, the kind of magnitude astronomers tend to use.

That the oceans are warming is no surprise: this has been obvious from the crudest comparison of old naval data with modern surface checks, and for years some researchers argued that ever-higher ocean temperatures could account for the so-called slowdown in global warming in the first dozen years of this century.

Challenging achievement

The new finding counts first as an academic achievement: there is now a more precise thermometer reading, and new calculations can begin.

One of the researchers, Ralph Keeling of the Scripps Institution of Oceanography, said: “The result significantly increases the confidence we can place in estimates of ocean warming and therefore help reduce uncertainty in the climate sensitivity, particularly closing off the possibility of very low climate sensitivity.”

But the result also suggests that internationally agreed attempts to hold planetary warming to a maximum of just 2°C – and the world has already warmed by around 1°C in the last century – become more challenging.

It means that there will have to be an even more drastic shutdown of fossil fuel investment and an even faster switch to renewable sources of energy such as sun and wind power. – Climate News Network

How Bangladesh can tackle rising seas

Salt levels in the coastal soils of Bangladesh will grow with the rising seas, putting two-fifths of its farmland at risk. Can farmers stay put?

LONDON, 29 October, 2018 − By 2140, rising seas are likely to be inundating the coastal lands (that are right now home to 1.3 billion people worldwide) in Bangladesh. Much of it is a vast estuarine silt bed fed by one of the world’s great river systems; the country is among those most vulnerable to sea level rise.

But, says a new study, many of the nation’s 165 million inhabitants may not be forced to become climate refugees.

As salty water seeps into the fertile muds and sands of the estuary of the Ganges-Brahmaputra river system, farmers could lose up to a fifth of their crop revenue each year.

An estimated 200,000 farmers may have to move inland. But the lucky ones with money to make the change may compensate by switching from rice cultivation to aquaculture, according to a new socio-economic study in the journal Nature Climate Change.

“The most vulnerable people will be the least resilient in the face of climate change, because they have limited resources to adapt”

“Unfortunately, this is likely to be most challenging for those farming families who have the fewest resources to begin with”, said Joyce Chen of the University of Ohio.

“My concern is that the most vulnerable people will be the least resilient in the face of climate change, because they have limited resources to adapt their farming practices or move longer distances in search of other employment.”

Bangladesh was once, notoriously, dismissed as a “basket case” by the US statesman Henry Kissinger. The low-lying terrain has always been vulnerable to the sea: in 1970, a storm surge propelled by a cyclone drove 10 metres of water over its lowlands, claiming an estimated 500,000 lives. In 1991, a six metre-high storm surge killed 138,000 and destroyed 10 million homes.

Global threat

Melting ice caps and expanding oceans threaten coasts everywhere: an estimated 13 million US citizens could be driven from their homes to count as climate refugees. But the spectre of sea level rise driven by profligate human combustion of fossil fuels puts Bangladesh in the front line of the challenge of climate change.

Dr Chen and a research colleague assembled as much data as they could about populations, incomes, soil geography and changing climate to try to guess what rising sea levels and ever-higher soil salinity will do to the nation over the next 120 years. Their calculations found 40% of the country’s croplands at risk, with coastal residents already experiencing frequent flooding.

But many of these had found ways to adapt: rice might not flourish in saline soil, but those who had made the big switch from crops to shrimp and fish farms had actually created more employment.

Accordingly, Dr Chen and her fellow researcher report that internal migration is likely to increase by at least 25%, as many are displaced by rising tides. But migration to other countries could actually fall by 66% because the supply of new work in labour-intensive fish farms could keep the locals at home.

Persistent risk

The coastal landscape will remain vulnerable to potentially devastating cyclones and storm surges, and this will be made worse by soil subsidence of from 10 to 18 mm a year.

Dr Chen sees her research as a test case for adaptation to climate change: other nations should take note. “The Bangladesh study offers interesting insights for governments of countries facing similar imminent threats of sea level rise,” she said.

“As internal migration patterns are expected to shift in countries vulnerable to sea level rise, ministries of planning may benefit from developing economic strategies that integrate and even leverage the expected additional number of workers coming from vulnerable areas.”

But, she warns, climate change will continue to create climate migrants. “Additional financial support from the international community may be necessary to foster resettlement programmes.” − Climate News Network

Salt levels in the coastal soils of Bangladesh will grow with the rising seas, putting two-fifths of its farmland at risk. Can farmers stay put?

LONDON, 29 October, 2018 − By 2140, rising seas are likely to be inundating the coastal lands (that are right now home to 1.3 billion people worldwide) in Bangladesh. Much of it is a vast estuarine silt bed fed by one of the world’s great river systems; the country is among those most vulnerable to sea level rise.

But, says a new study, many of the nation’s 165 million inhabitants may not be forced to become climate refugees.

As salty water seeps into the fertile muds and sands of the estuary of the Ganges-Brahmaputra river system, farmers could lose up to a fifth of their crop revenue each year.

An estimated 200,000 farmers may have to move inland. But the lucky ones with money to make the change may compensate by switching from rice cultivation to aquaculture, according to a new socio-economic study in the journal Nature Climate Change.

“The most vulnerable people will be the least resilient in the face of climate change, because they have limited resources to adapt”

“Unfortunately, this is likely to be most challenging for those farming families who have the fewest resources to begin with”, said Joyce Chen of the University of Ohio.

“My concern is that the most vulnerable people will be the least resilient in the face of climate change, because they have limited resources to adapt their farming practices or move longer distances in search of other employment.”

Bangladesh was once, notoriously, dismissed as a “basket case” by the US statesman Henry Kissinger. The low-lying terrain has always been vulnerable to the sea: in 1970, a storm surge propelled by a cyclone drove 10 metres of water over its lowlands, claiming an estimated 500,000 lives. In 1991, a six metre-high storm surge killed 138,000 and destroyed 10 million homes.

Global threat

Melting ice caps and expanding oceans threaten coasts everywhere: an estimated 13 million US citizens could be driven from their homes to count as climate refugees. But the spectre of sea level rise driven by profligate human combustion of fossil fuels puts Bangladesh in the front line of the challenge of climate change.

Dr Chen and a research colleague assembled as much data as they could about populations, incomes, soil geography and changing climate to try to guess what rising sea levels and ever-higher soil salinity will do to the nation over the next 120 years. Their calculations found 40% of the country’s croplands at risk, with coastal residents already experiencing frequent flooding.

But many of these had found ways to adapt: rice might not flourish in saline soil, but those who had made the big switch from crops to shrimp and fish farms had actually created more employment.

Accordingly, Dr Chen and her fellow researcher report that internal migration is likely to increase by at least 25%, as many are displaced by rising tides. But migration to other countries could actually fall by 66% because the supply of new work in labour-intensive fish farms could keep the locals at home.

Persistent risk

The coastal landscape will remain vulnerable to potentially devastating cyclones and storm surges, and this will be made worse by soil subsidence of from 10 to 18 mm a year.

Dr Chen sees her research as a test case for adaptation to climate change: other nations should take note. “The Bangladesh study offers interesting insights for governments of countries facing similar imminent threats of sea level rise,” she said.

“As internal migration patterns are expected to shift in countries vulnerable to sea level rise, ministries of planning may benefit from developing economic strategies that integrate and even leverage the expected additional number of workers coming from vulnerable areas.”

But, she warns, climate change will continue to create climate migrants. “Additional financial support from the international community may be necessary to foster resettlement programmes.” − Climate News Network

Historic sites face risk from rising seas

Venice has been at hazard from rising seas for years. But so now are almost all historic sites near Mediterranean coasts, a survey finds.

LONDON, 25 October, 2018 − Some of the planet’s most historic sites could by 2100 face damage or outright destruction in a warming world. Scientists who surveyed 49 World Heritage Sites in the Mediterranean report that 47 of them are at some degree of risk from future sea level rise.

As ever-higher levels of carbon dioxide enter the atmosphere to warm the planet, so global sea levels creep ever higher. And this constant threat of attrition by ever-higher tides and storm surges poses an ever-higher risk to a suite of cities, sites and ruins declared by UNESCO, the UN Educational, Scientific and Cultural Organisation, to be of global importance, and in need of careful preservation.

The locations most at risk include the city of Venice, the medieval city of Rhodes, the old city of Dubrovnik, and the ruins of Carthage in Tunisia.

The researchers considered the hazard of what is now a once-in-a-century storm surge occurring, as the seas rise by almost 1.5 metres by 2100. By then, they found, storm surges that now occur once a century could be happening several times every year.

“Many of these heritage sites will slowly disappear with sea level rise, even though these sites are important parts of human history”

Increasingly, coastal flooding and erosion could damage, deface or completely obliterate landmarks that played a pivotal role in world history. All the sites have important intangible value as icons of civilisation; many of them are popular tourist destinations, and their disappearance could only mean huge economic losses as well.

Such studies are launched to alert governments, civic authorities and communities to the need for action. Venice, in particular, has been a subject of national and international concern for decades. The surprise in the latest research, in the journal Nature Communications, is that of the 49 sites investigated, 37 are vulnerable to storm surge, 42 to coastal erosion − and many of them to both.

“In the Mediterranean, the risk posed by storm surges, which are 100-year storm surges under today’s conditions, may increase by up to 50% on average, and that from coastal erosions by up to 13% − and all this by the end of the 21st century under high sea level rise,” said Lena Reimann of Kiel University in Germany, who led the study.

“Individual World Heritage Sites could even be affected much more, due to their exposed location.”

Low-lying coastal sites

The researchers started with a database of all the low-lying UNESCO coastal sites: they noted the distance of each site from the coast, whether the terrain was rocky or sandy, and the chance that a build-up of silts from the Nile, the Rhone or the Po rivers might offer protection. They took as their danger baseline a predicted 1.46 metre rise in the level of the Mediterranean by the century’s end.

A rise as high as this has a low probability, but cannot be ruled out. And since the stakes are high − a city like Venice cannot be relocated, and the engineering challenge of protecting its lagoon from flooding is huge − even a one-in-20 hazard is taken seriously.

Other research studies have warned that just a 50 centimetre rise in sea levels places vast tracts of European coastline at risk from storm surge − the dangerous combination of very high tide and very strong winds − and could impose colossal costs on cities from Rotterdam to Istanbul.

Already at risk

The latest study warns that by the end of the century, only two of the 49 sites would be at risk from neither erosion nor flooding. And more than 90% of the sites identified are, the researchers say, already at risk under current conditions, “which stresses the urgency of adaptation in these locations.”

And, they say, action and adaptation should start now. There are plenty of other historic sites to think about.

“Cultural heritage not inscribed in the World Heritage list will receive much less attention and many of these heritage sites will slowly disappear with sea level rise, even though these sites are important parts of human history as well,” they conclude. − Climate News Network

Venice has been at hazard from rising seas for years. But so now are almost all historic sites near Mediterranean coasts, a survey finds.

LONDON, 25 October, 2018 − Some of the planet’s most historic sites could by 2100 face damage or outright destruction in a warming world. Scientists who surveyed 49 World Heritage Sites in the Mediterranean report that 47 of them are at some degree of risk from future sea level rise.

As ever-higher levels of carbon dioxide enter the atmosphere to warm the planet, so global sea levels creep ever higher. And this constant threat of attrition by ever-higher tides and storm surges poses an ever-higher risk to a suite of cities, sites and ruins declared by UNESCO, the UN Educational, Scientific and Cultural Organisation, to be of global importance, and in need of careful preservation.

The locations most at risk include the city of Venice, the medieval city of Rhodes, the old city of Dubrovnik, and the ruins of Carthage in Tunisia.

The researchers considered the hazard of what is now a once-in-a-century storm surge occurring, as the seas rise by almost 1.5 metres by 2100. By then, they found, storm surges that now occur once a century could be happening several times every year.

“Many of these heritage sites will slowly disappear with sea level rise, even though these sites are important parts of human history”

Increasingly, coastal flooding and erosion could damage, deface or completely obliterate landmarks that played a pivotal role in world history. All the sites have important intangible value as icons of civilisation; many of them are popular tourist destinations, and their disappearance could only mean huge economic losses as well.

Such studies are launched to alert governments, civic authorities and communities to the need for action. Venice, in particular, has been a subject of national and international concern for decades. The surprise in the latest research, in the journal Nature Communications, is that of the 49 sites investigated, 37 are vulnerable to storm surge, 42 to coastal erosion − and many of them to both.

“In the Mediterranean, the risk posed by storm surges, which are 100-year storm surges under today’s conditions, may increase by up to 50% on average, and that from coastal erosions by up to 13% − and all this by the end of the 21st century under high sea level rise,” said Lena Reimann of Kiel University in Germany, who led the study.

“Individual World Heritage Sites could even be affected much more, due to their exposed location.”

Low-lying coastal sites

The researchers started with a database of all the low-lying UNESCO coastal sites: they noted the distance of each site from the coast, whether the terrain was rocky or sandy, and the chance that a build-up of silts from the Nile, the Rhone or the Po rivers might offer protection. They took as their danger baseline a predicted 1.46 metre rise in the level of the Mediterranean by the century’s end.

A rise as high as this has a low probability, but cannot be ruled out. And since the stakes are high − a city like Venice cannot be relocated, and the engineering challenge of protecting its lagoon from flooding is huge − even a one-in-20 hazard is taken seriously.

Other research studies have warned that just a 50 centimetre rise in sea levels places vast tracts of European coastline at risk from storm surge − the dangerous combination of very high tide and very strong winds − and could impose colossal costs on cities from Rotterdam to Istanbul.

Already at risk

The latest study warns that by the end of the century, only two of the 49 sites would be at risk from neither erosion nor flooding. And more than 90% of the sites identified are, the researchers say, already at risk under current conditions, “which stresses the urgency of adaptation in these locations.”

And, they say, action and adaptation should start now. There are plenty of other historic sites to think about.

“Cultural heritage not inscribed in the World Heritage list will receive much less attention and many of these heritage sites will slowly disappear with sea level rise, even though these sites are important parts of human history as well,” they conclude. − Climate News Network