Tag Archives: Oceans

Cold-blooded sealife runs double heat risk

Extremes of heat are twice as risky for cold-blooded sealife as for other ectotherms. A hot rock could be safer than the deep sea.

LONDON, 29 April, 2019 – When it comes to global warming, there may no longer be plenty of fish in the sea: new research suggests that cold-blooded sealife may be twice as likely to be at risk in its natural habitat as land-dwelling ectotherms.

This finding is unexpected: the ocean is, in both area and volume, the single biggest living space on the planet. Fish that feel the heat can move towards the poles when temperatures get too high.

But when US researchers took a closer look at the data available on the thermal discomfort zones – those moments when cold-blooded creatures begin to overheat and need to find a safe, cool place in which to lie low – those spiders and lizards that survive in the tropics and temperate zones actually stand a better chance of finding somewhere to hide, and thus living through heatwaves, than their marine cousins.

“New conservation efforts will be needed if the ocean is going to continue supporting human well-being, nutrition and economic activity”

“We find that, globally, marine species are being eliminated from their habitats by warming temperatures twice as often as land species,” said Malin Pinsky, of Rutgers University in New Brunswick.

“The findings suggest that new conservation efforts will be needed if the ocean is going to continue supporting human well-being, nutrition and economic activity.”

He and colleagues report in the journal Nature that they searched the literature for detailed information on 400 species, and calculated the safe conditions for 88 marine and 294 land animals. They also identified the coolest temperatures available to each species during the hottest parts of the year.

More terrestrial refuges

And they found that, on average, fish and marine animals were more likely to live on the edge of temperatures that could become dangerously high. Land animals – insects and reptiles – could disappear into the forests, seek the shade or go underground: something sea creatures could not do.

That terrestrial reptiles and amphibians and marine animals are at risk is not news: researchers have already recorded significant movements of sea species in response to heat extremes off the Californian coast.

There has been repeated evidence that rising global temperature, as a consequence of greenhouse gas emissions from fossil fuel use, has begun to affect commercial fisheries, and other researchers have made it emphatically clear that only determined human action to contain global warming and protect breeding grounds can keep fish on the family supper table.

What most would not have expected was to find that land animals were less at risk, simply because they were land-dwellers.

Limited evidence

Research of this kind tends to deliver findings that can be challenged, and the authors concede that their conclusions are limited by the available evidence. Of 159 separate studies, 153 were in the northern hemisphere and 137 were from the temperate latitudes. Of their marine ectotherms, only 7% were pelagic: these are the fish – among them cod and tuna – that can swim to deeper, cooler layers when surface temperatures soar.

The remaining 93% included slow-moving bottom-dwellers such as lobsters, horseshoe crabs, abalone and snails, which may have nowhere left to go when life locally gets too hot to handle. The researchers make it clear that they are not talking about complete global extinctions of species: they choose the phrase “local extirpations”.

And they make it clear that land-dwelling cold-blooded animals are by no means safe from increasingly frequent, intense episodes of heat extremes driven by climate change: they would continue to be vulnerable to loss of what the researchers call “local refugia” – for example woodland cover – which “would make habitat fragmentation and changes in land use critical drivers of species loss on land.” – Climate News Network

Extremes of heat are twice as risky for cold-blooded sealife as for other ectotherms. A hot rock could be safer than the deep sea.

LONDON, 29 April, 2019 – When it comes to global warming, there may no longer be plenty of fish in the sea: new research suggests that cold-blooded sealife may be twice as likely to be at risk in its natural habitat as land-dwelling ectotherms.

This finding is unexpected: the ocean is, in both area and volume, the single biggest living space on the planet. Fish that feel the heat can move towards the poles when temperatures get too high.

But when US researchers took a closer look at the data available on the thermal discomfort zones – those moments when cold-blooded creatures begin to overheat and need to find a safe, cool place in which to lie low – those spiders and lizards that survive in the tropics and temperate zones actually stand a better chance of finding somewhere to hide, and thus living through heatwaves, than their marine cousins.

“New conservation efforts will be needed if the ocean is going to continue supporting human well-being, nutrition and economic activity”

“We find that, globally, marine species are being eliminated from their habitats by warming temperatures twice as often as land species,” said Malin Pinsky, of Rutgers University in New Brunswick.

“The findings suggest that new conservation efforts will be needed if the ocean is going to continue supporting human well-being, nutrition and economic activity.”

He and colleagues report in the journal Nature that they searched the literature for detailed information on 400 species, and calculated the safe conditions for 88 marine and 294 land animals. They also identified the coolest temperatures available to each species during the hottest parts of the year.

More terrestrial refuges

And they found that, on average, fish and marine animals were more likely to live on the edge of temperatures that could become dangerously high. Land animals – insects and reptiles – could disappear into the forests, seek the shade or go underground: something sea creatures could not do.

That terrestrial reptiles and amphibians and marine animals are at risk is not news: researchers have already recorded significant movements of sea species in response to heat extremes off the Californian coast.

There has been repeated evidence that rising global temperature, as a consequence of greenhouse gas emissions from fossil fuel use, has begun to affect commercial fisheries, and other researchers have made it emphatically clear that only determined human action to contain global warming and protect breeding grounds can keep fish on the family supper table.

What most would not have expected was to find that land animals were less at risk, simply because they were land-dwellers.

Limited evidence

Research of this kind tends to deliver findings that can be challenged, and the authors concede that their conclusions are limited by the available evidence. Of 159 separate studies, 153 were in the northern hemisphere and 137 were from the temperate latitudes. Of their marine ectotherms, only 7% were pelagic: these are the fish – among them cod and tuna – that can swim to deeper, cooler layers when surface temperatures soar.

The remaining 93% included slow-moving bottom-dwellers such as lobsters, horseshoe crabs, abalone and snails, which may have nowhere left to go when life locally gets too hot to handle. The researchers make it clear that they are not talking about complete global extinctions of species: they choose the phrase “local extirpations”.

And they make it clear that land-dwelling cold-blooded animals are by no means safe from increasingly frequent, intense episodes of heat extremes driven by climate change: they would continue to be vulnerable to loss of what the researchers call “local refugia” – for example woodland cover – which “would make habitat fragmentation and changes in land use critical drivers of species loss on land.” – Climate News Network

Fast Arctic melt could cost $70 trillion

Polar change, notably the fast Arctic melt, could impose huge costs on world economies. New evidence shows how rapidly the frozen north is changing.

LONDON, 26 April, 2019 – The northern reaches of the planet are undergoing very rapid change: the fast Arctic melt means the region is warming at twice the speed of the planetary average.

The loss of sea ice and land snow could tip the planet into a new and unprecedented cycle of climatic change and add yet another $70 trillion (£54 tn) to the estimated economic cost of global warming.

In yet another sombre statement of the challenge presented by climate change, driven by ever-increasing emissions of greenhouse gases from the fossil fuels that power the global economy, British, European and US researchers took a look at two manifestations of warming.

One is the growing levels of ancient carbon now being released into the atmosphere as the Arctic permafrost begins to melt. The other is the reduced reflection of solar radiation back into space as what had once been an expanse of snow and ice melts, to expose ever greater areas of light-absorbing blue sea, dark rock and scrubby tundra.

Abrupt surprises

The concern is with what the scientists like to call “non-linear transitions”. The fear is not that global warming will simply get more pronounced as more snow and ice disappears. The fear is that at some point the melting will reach a threshold that could tip the planet into a new climate regime that would be irreversible, and for which there has been no parallel in human history.

And if so, the costs in terms of climate disruption, heat waves, rising sea levels, harvest failures, more violent storms and more devastating floods and so on could start to soar.

The scientists report in the journal Nature Communications that if the nations of the world were to keep a promise made in Paris in 2015 to contain planetary warming to “well below” 2°C above the average for most of human history by the year 2100, the extra cost of Arctic ice loss would still tip $24 tn.

But on the evidence of national plans tabled so far, the world seems on course to hit 3°C by the century’s end, and the extra cost to the global economies is estimated at almost $70 tn.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic”

If the world goes on burning more and more fossil fuels – this is called the business-as-usual scenario – then global temperatures could rise to 4°C above the historic average by 2100. The bill for what the scientists call “the most expensive and least desirable scenario” is set at $2197 tn. And, they stress, their forecast $70 tn is just the extra cost of the melting Arctic.

They have not factored in all the other much-feared potential “tipping points” such as the loss of the tropical rainforests that absorb so much of the atmospheric carbon, the collapse of the great Atlantic current that distributes equatorial heat to temperate climates, the loss of the West Antarctic ice sheet, and other irreversible changes.

As they see it, even to contain global warming to 1.5°C by 2100 could cost a global $600 trillion.

And although the thawing of the permafrost and the opening of the Arctic Ocean would deliver mining and shipping opportunities, any such rewards would be dwarfed by the cost of the emissions from the thawing permafrost, and the reduction of what scientists call albedo: the reflectivity of pristine ice and snow that helps keep the Arctic frozen.

Model-based estimates

Research of this kind is based on vast numbers of simulations of the global economies under a range of scenarios, and the calculations of cost remain just that, estimates based on models of what nations might or might not do. The price economies must pay will be real enough, but the advanced accounting of what has yet to happen remains academic.

But the changes in the Arctic are far from academic, according to a series of new studies of what has been happening, and is happening right now.

●Researchers in California report in the Proceedings of the National Academy of Sciences that they have now reconstructed change in the Greenland ice sheet between 1972 and 2018, to estimate the loss of ice.

Fifty years ago, the northern hemisphere’s greatest sheet of ice was losing 47 billion tonnes of ice every year, and by the next decade 50 bn tonnes annually.

Sea levels raised

Since then the losses have risen almost six-fold, and since 2010 the island has been losing ice at the rate of 290 billion tonnes a year. So far, ice from Greenland alone has raised sea levels by almost 14 mm.

●German scientists have looked at the results of 15 years of observations by the Grace satellite system – the acronym stands for Gravity Recovery and Climate Experiment – which ended in 2018. They calculate that between April 2002 and June 2017, Greenland lost about 260 bn tonnes of ice each year, and Antarctica 140 bn tonnes.

They warn in the journal Nature Climate Change that melting at this rate could accelerate sea level rise to 10 mm a year – faster than at any time in the last 5,000 years – as a direct consequence of a warming climate.

●And the traffic of sea ice across the Arctic ocean has begun to falter, according to German oceanographers. The Transpolar Drift is a slow flow of new sea ice from the Siberian Arctic across the pole to the Fram Strait east of Greenland.

Melting too early

It has its place in the history of polar exploration: in 1893 the Norwegian explorer Fridtjof Nansen deliberately sailed his ship the Fram into the ice pack off Siberia and went with the floes across the Arctic.

The Drift is a kind of frozen ocean conveyor that carries nutrients, algae and sediments across the pole. But, researchers say in the journal Scientific Reports, this flow has started to vary. Most of the young ice off the Siberian coast now melts before it can leave its “nursery”. Once, half the ice from the Russian shelf completed the journey. Now, only one-fifth does.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic,” said Thomas Krumpen of the Alfred Wegener Institute, who led the study.

“The ice now leaving the Arctic through the Fram Strait is, on average, 30% thinner than it was 15 years ago.” – Climate News Network

Polar change, notably the fast Arctic melt, could impose huge costs on world economies. New evidence shows how rapidly the frozen north is changing.

LONDON, 26 April, 2019 – The northern reaches of the planet are undergoing very rapid change: the fast Arctic melt means the region is warming at twice the speed of the planetary average.

The loss of sea ice and land snow could tip the planet into a new and unprecedented cycle of climatic change and add yet another $70 trillion (£54 tn) to the estimated economic cost of global warming.

In yet another sombre statement of the challenge presented by climate change, driven by ever-increasing emissions of greenhouse gases from the fossil fuels that power the global economy, British, European and US researchers took a look at two manifestations of warming.

One is the growing levels of ancient carbon now being released into the atmosphere as the Arctic permafrost begins to melt. The other is the reduced reflection of solar radiation back into space as what had once been an expanse of snow and ice melts, to expose ever greater areas of light-absorbing blue sea, dark rock and scrubby tundra.

Abrupt surprises

The concern is with what the scientists like to call “non-linear transitions”. The fear is not that global warming will simply get more pronounced as more snow and ice disappears. The fear is that at some point the melting will reach a threshold that could tip the planet into a new climate regime that would be irreversible, and for which there has been no parallel in human history.

And if so, the costs in terms of climate disruption, heat waves, rising sea levels, harvest failures, more violent storms and more devastating floods and so on could start to soar.

The scientists report in the journal Nature Communications that if the nations of the world were to keep a promise made in Paris in 2015 to contain planetary warming to “well below” 2°C above the average for most of human history by the year 2100, the extra cost of Arctic ice loss would still tip $24 tn.

But on the evidence of national plans tabled so far, the world seems on course to hit 3°C by the century’s end, and the extra cost to the global economies is estimated at almost $70 tn.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic”

If the world goes on burning more and more fossil fuels – this is called the business-as-usual scenario – then global temperatures could rise to 4°C above the historic average by 2100. The bill for what the scientists call “the most expensive and least desirable scenario” is set at $2197 tn. And, they stress, their forecast $70 tn is just the extra cost of the melting Arctic.

They have not factored in all the other much-feared potential “tipping points” such as the loss of the tropical rainforests that absorb so much of the atmospheric carbon, the collapse of the great Atlantic current that distributes equatorial heat to temperate climates, the loss of the West Antarctic ice sheet, and other irreversible changes.

As they see it, even to contain global warming to 1.5°C by 2100 could cost a global $600 trillion.

And although the thawing of the permafrost and the opening of the Arctic Ocean would deliver mining and shipping opportunities, any such rewards would be dwarfed by the cost of the emissions from the thawing permafrost, and the reduction of what scientists call albedo: the reflectivity of pristine ice and snow that helps keep the Arctic frozen.

Model-based estimates

Research of this kind is based on vast numbers of simulations of the global economies under a range of scenarios, and the calculations of cost remain just that, estimates based on models of what nations might or might not do. The price economies must pay will be real enough, but the advanced accounting of what has yet to happen remains academic.

But the changes in the Arctic are far from academic, according to a series of new studies of what has been happening, and is happening right now.

●Researchers in California report in the Proceedings of the National Academy of Sciences that they have now reconstructed change in the Greenland ice sheet between 1972 and 2018, to estimate the loss of ice.

Fifty years ago, the northern hemisphere’s greatest sheet of ice was losing 47 billion tonnes of ice every year, and by the next decade 50 bn tonnes annually.

Sea levels raised

Since then the losses have risen almost six-fold, and since 2010 the island has been losing ice at the rate of 290 billion tonnes a year. So far, ice from Greenland alone has raised sea levels by almost 14 mm.

●German scientists have looked at the results of 15 years of observations by the Grace satellite system – the acronym stands for Gravity Recovery and Climate Experiment – which ended in 2018. They calculate that between April 2002 and June 2017, Greenland lost about 260 bn tonnes of ice each year, and Antarctica 140 bn tonnes.

They warn in the journal Nature Climate Change that melting at this rate could accelerate sea level rise to 10 mm a year – faster than at any time in the last 5,000 years – as a direct consequence of a warming climate.

●And the traffic of sea ice across the Arctic ocean has begun to falter, according to German oceanographers. The Transpolar Drift is a slow flow of new sea ice from the Siberian Arctic across the pole to the Fram Strait east of Greenland.

Melting too early

It has its place in the history of polar exploration: in 1893 the Norwegian explorer Fridtjof Nansen deliberately sailed his ship the Fram into the ice pack off Siberia and went with the floes across the Arctic.

The Drift is a kind of frozen ocean conveyor that carries nutrients, algae and sediments across the pole. But, researchers say in the journal Scientific Reports, this flow has started to vary. Most of the young ice off the Siberian coast now melts before it can leave its “nursery”. Once, half the ice from the Russian shelf completed the journey. Now, only one-fifth does.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic,” said Thomas Krumpen of the Alfred Wegener Institute, who led the study.

“The ice now leaving the Arctic through the Fram Strait is, on average, 30% thinner than it was 15 years ago.” – Climate News Network

Climate science supports youth protests

The youth protests urging political action on climate change have won strong global backing from climatologists, as over 6,000 scientists express their support.

LONDON, 19 April, 2019 – The global youth protests demanding action on climate change are having a marked effect.

In their thousands, concerned climate scientists, backed by colleagues from other disciplines, are voicing support for the school students and other young people who are staying away from lessons to urge more resolute political action to protect the climate.

The campaign to support the protesters has been launched by an international group of 22 scientists spanning a range of disciplines; several of them are renowned climate specialists.

They include Michael Mann, professor of atmospheric science at Penn State University, US, Kevin Anderson, professor of energy and climate change at the University of Manchester, UK, and Stefan Rahmstorf.

Reasons to protest

Climate News Network asked Stefan Rahmstorf, professor of physics of the oceans at the University of Potsdam, Germany, what he would tell a hesitant potential protester in order to allay his or her doubts.

He replied: “Politicians are already starting to move in response to the school strikes around the world. Fridays for Future is perhaps our last chance to get meaningful climate policies that can still achieve the goals of the Paris Agreement. Time is running out fast.”

By mid-April the scientists who had signed the declaration numbered almost 6,300. The 22 original signatories  explained why they backed the protests in a letter to the journal Science headed Concerns of young protesters are justified.

Known as Scientists for Future International, they are linked to the website which co-ordinates the protests worldwide, Fridays for Future (the protests are held on Fridays).

Justified concerns

The letter starts with a ringing declaration: “The world’s youth have begun to persistently demonstrate for the protection of the climate and other foundations of human well-being … Their concerns are justified and supported by the best available science. The current measures for protecting the climate and biosphere are deeply inadequate.”

It includes a clear call to move from protest to action to tackle the multiple environmental threats now confronting the next generation: limiting global warming, halting the mass extinction of other species and safeguarding food supplies.

“This is what the young people want to achieve. They deserve our respect and full support.”

In March the estimated worldwide number of protesters was around 1.5 million.

“Politicians are already starting to move in response to the school strikes around the world. Fridays for Future is perhaps our last chance to get meaningful climate policies

In support of its declaration of backing for the protesters, Scientists for Future International says almost every country has signed and ratified the Paris Agreement of 2015, agreeing to keep global warming well below 2°C above pre-industrial levels, and aiming to limit the temperature increase to 1.5°C.

“The scientific community has clearly concluded that a global warming of 2°C instead of 1.5°C would substantially increase climate-related impacts and the risk of some becoming irreversible.

“It is critical to immediately begin a rapid reduction in CO2 and other greenhouse gas emissions. The degree of climate crisis that humanity will experience in the future will be determined by our cumulative emissions; rapid reduction now will limit the damage.

“For example, the Intergovernmental Panel on Climate Change (IPCC) has recently assessed that halving CO2 emissions by 2030 (relative to 2010 levels) and globally achieving net-zero CO2 emissions by 2050 (as well as strong reductions in other greenhouse gases) would allow a 50% chance of staying below 1.5°C of warming.”

Time is short

It says many solutions to the climate crisis already exist, and only bold action can avert the critical danger that threatens the protesters’ future. It adds: “There is no time to wait until they are in power.”

The statement ends: “The enormous grassroots mobilisation of the youth climate movement … shows that young people understand the situation. We approve and support their demand for rapid and forceful action. We see it as our social, ethical, and scholarly responsibility to state [this] in no uncertain terms.

“Only if humanity acts quickly and resolutely can we limit global warming, halt the ongoing mass extinction of animal and plant species, and preserve the natural basis for the food supply and well-being of present and future generations.

“This is what the young people want to achieve. They deserve our respect and full support.” –  Climate News Network

* * * * *

Anyone wanting to add their names to the Scientists for Future International declaration – and who meets its eligibility requirements – will find it here. It is published under a Creative Commons licence (CC BY-SA 4.0) and can be freely shared.

The youth protests urging political action on climate change have won strong global backing from climatologists, as over 6,000 scientists express their support.

LONDON, 19 April, 2019 – The global youth protests demanding action on climate change are having a marked effect.

In their thousands, concerned climate scientists, backed by colleagues from other disciplines, are voicing support for the school students and other young people who are staying away from lessons to urge more resolute political action to protect the climate.

The campaign to support the protesters has been launched by an international group of 22 scientists spanning a range of disciplines; several of them are renowned climate specialists.

They include Michael Mann, professor of atmospheric science at Penn State University, US, Kevin Anderson, professor of energy and climate change at the University of Manchester, UK, and Stefan Rahmstorf.

Reasons to protest

Climate News Network asked Stefan Rahmstorf, professor of physics of the oceans at the University of Potsdam, Germany, what he would tell a hesitant potential protester in order to allay his or her doubts.

He replied: “Politicians are already starting to move in response to the school strikes around the world. Fridays for Future is perhaps our last chance to get meaningful climate policies that can still achieve the goals of the Paris Agreement. Time is running out fast.”

By mid-April the scientists who had signed the declaration numbered almost 6,300. The 22 original signatories  explained why they backed the protests in a letter to the journal Science headed Concerns of young protesters are justified.

Known as Scientists for Future International, they are linked to the website which co-ordinates the protests worldwide, Fridays for Future (the protests are held on Fridays).

Justified concerns

The letter starts with a ringing declaration: “The world’s youth have begun to persistently demonstrate for the protection of the climate and other foundations of human well-being … Their concerns are justified and supported by the best available science. The current measures for protecting the climate and biosphere are deeply inadequate.”

It includes a clear call to move from protest to action to tackle the multiple environmental threats now confronting the next generation: limiting global warming, halting the mass extinction of other species and safeguarding food supplies.

“This is what the young people want to achieve. They deserve our respect and full support.”

In March the estimated worldwide number of protesters was around 1.5 million.

“Politicians are already starting to move in response to the school strikes around the world. Fridays for Future is perhaps our last chance to get meaningful climate policies

In support of its declaration of backing for the protesters, Scientists for Future International says almost every country has signed and ratified the Paris Agreement of 2015, agreeing to keep global warming well below 2°C above pre-industrial levels, and aiming to limit the temperature increase to 1.5°C.

“The scientific community has clearly concluded that a global warming of 2°C instead of 1.5°C would substantially increase climate-related impacts and the risk of some becoming irreversible.

“It is critical to immediately begin a rapid reduction in CO2 and other greenhouse gas emissions. The degree of climate crisis that humanity will experience in the future will be determined by our cumulative emissions; rapid reduction now will limit the damage.

“For example, the Intergovernmental Panel on Climate Change (IPCC) has recently assessed that halving CO2 emissions by 2030 (relative to 2010 levels) and globally achieving net-zero CO2 emissions by 2050 (as well as strong reductions in other greenhouse gases) would allow a 50% chance of staying below 1.5°C of warming.”

Time is short

It says many solutions to the climate crisis already exist, and only bold action can avert the critical danger that threatens the protesters’ future. It adds: “There is no time to wait until they are in power.”

The statement ends: “The enormous grassroots mobilisation of the youth climate movement … shows that young people understand the situation. We approve and support their demand for rapid and forceful action. We see it as our social, ethical, and scholarly responsibility to state [this] in no uncertain terms.

“Only if humanity acts quickly and resolutely can we limit global warming, halt the ongoing mass extinction of animal and plant species, and preserve the natural basis for the food supply and well-being of present and future generations.

“This is what the young people want to achieve. They deserve our respect and full support.” –  Climate News Network

* * * * *

Anyone wanting to add their names to the Scientists for Future International declaration – and who meets its eligibility requirements – will find it here. It is published under a Creative Commons licence (CC BY-SA 4.0) and can be freely shared.

Hunger is growing as the world warms faster

Climate change is speeding up, and among its malign impacts is a setback for efforts to feed the world: hunger is growing again.

LONDON, 29 March, 2019 − The global threat of hunger is growing again after years of progress in reducing it, the United Nations says, because of the effects of climate change.

It says this is just one aspect of a wider acceleration in the pace of the changes wrought by the world’s unremitting consumption of fossil fuels and the consequential rise in global temperatures..

The evidence that hunger and malnutrition are once again on the rise is published in a new report from the World Meteorological Organization (WMO) on the state of the global climate in 2018.

The report, drawing on material from scientists, UN agencies and countries’ own meteorological services, says the physical signs and the impacts of climate change are speeding up as record greenhouse gas concentrations drive global temperatures towards increasingly dangerous levels.

“New evidence shows a continuing rise in world hunger after a prolonged decline . . . ”

Highlighting record sea level rise and exceptionally high land and ocean temperatures over the past four years, the report warns that this warming trend has lasted since the start of this century and is expected to continue.

Carbon dioxide levels, which were at 357.0 parts per million when the first statement in the series was published in 1994, keep rising − to 405.5 ppm in 2017. Greenhouse gas concentrations for 2018 and 2019 are expected to show a further increase.

The start of 2019 has seen warm record daily winter temperatures in Europe, unusual cold in North America and searing heatwaves in Australia. Arctic and Antarctic ice extent is yet again well below average.

In a statement the UN secretary-general, António Guterres, writes that the data released in the report “give cause for great concern. The past four years were the warmest on record, with the global average surface temperature in 2018 approximately 1°C above the pre-industrial baseline … There is no longer any time for delay.”

Four warming years

The WMO secretary-general, Petteri Taalas, says: “Key findings of this statement include the striking consecutive record warming recorded from 2015 through 2018, the continuous upward trend in the atmospheric concentrations of the major greenhouse gases, the increasing rate of sea level rise and the loss of sea ice in both northern and southern polar regions.”

One particular concern highlighted is food security. In the words of the report, “exposure of the agriculture sector to climate extremes is threatening to reverse gains made in ending malnutrition.

“New evidence shows a continuing rise in world hunger  after a prolonged decline, according to data compiled by UN agencies including the Food and Agriculture Organization (FAO) and World Food Programme.

“In 2017, the number of undernourished people was estimated to have increased to 821 million, partly due to severe droughts associated with the strong El Niño of 2015–2016.”

Climate refugees

The FAO says the absolute number of undernourished people − those facing chronic food deprivation − reached  nearly 821 m in 2017, from around 804 m in 2016.

The WMO report also singles out the plight of those forced by climate change to leave their homes and become refugees, either within their own countries or abroad. Out of 17.7 m people classified as internally displaced persons (IDPs) tracked by the International Organization for Migration, it says, by September 2018 over 2 m people had been displaced by disasters linked to weather and climate events.

According to the UN refugee agency UNHCR’s Protection and Return Monitoring Network, about 883,000 new internal displacements were recorded between January and December 2018, of which 32% were associated with flooding and 29% with drought.

Hundreds of thousands of Rohingya refugees were affected by what the UN calls “secondary displacement”, caused by extreme events, heavy rain, flooding and landslides.

More acid seas

The WMO also expresses concern about a range of impacts of climate change on the global environment, including reduced levels of oxygen in the oceans. Since the middle of the last century there has been an estimated 1-2% decrease in the amount of oxygen in the world’s oceans, according to UNESCO’s Intergovernmental Oceanographic Commission (UNESCO-IOC).

In the past decade the oceans have absorbed around 30% of CO2 emissions of human origin. Absorbed CO2 reacts with seawater and changes the pH of the ocean. This process, known as ocean acidification, can affect the ability of marine organisms such as molluscs and reef-building corals, to build and maintain shells and skeletal material.

Observations in the open ocean over the last 30 years have shown a clear trend of decreasing pH. In line with previous reports and projections, ocean acidification is ongoing and the global pH levels continue to decrease, according to UNESCO-IOC. One recent report suggested possible alarming future impacts.

The State of the Climate report will be one of WMO’s contributions to the UN’s Climate Action Summit on 23 September. − Climate News Network

Climate change is speeding up, and among its malign impacts is a setback for efforts to feed the world: hunger is growing again.

LONDON, 29 March, 2019 − The global threat of hunger is growing again after years of progress in reducing it, the United Nations says, because of the effects of climate change.

It says this is just one aspect of a wider acceleration in the pace of the changes wrought by the world’s unremitting consumption of fossil fuels and the consequential rise in global temperatures..

The evidence that hunger and malnutrition are once again on the rise is published in a new report from the World Meteorological Organization (WMO) on the state of the global climate in 2018.

The report, drawing on material from scientists, UN agencies and countries’ own meteorological services, says the physical signs and the impacts of climate change are speeding up as record greenhouse gas concentrations drive global temperatures towards increasingly dangerous levels.

“New evidence shows a continuing rise in world hunger after a prolonged decline . . . ”

Highlighting record sea level rise and exceptionally high land and ocean temperatures over the past four years, the report warns that this warming trend has lasted since the start of this century and is expected to continue.

Carbon dioxide levels, which were at 357.0 parts per million when the first statement in the series was published in 1994, keep rising − to 405.5 ppm in 2017. Greenhouse gas concentrations for 2018 and 2019 are expected to show a further increase.

The start of 2019 has seen warm record daily winter temperatures in Europe, unusual cold in North America and searing heatwaves in Australia. Arctic and Antarctic ice extent is yet again well below average.

In a statement the UN secretary-general, António Guterres, writes that the data released in the report “give cause for great concern. The past four years were the warmest on record, with the global average surface temperature in 2018 approximately 1°C above the pre-industrial baseline … There is no longer any time for delay.”

Four warming years

The WMO secretary-general, Petteri Taalas, says: “Key findings of this statement include the striking consecutive record warming recorded from 2015 through 2018, the continuous upward trend in the atmospheric concentrations of the major greenhouse gases, the increasing rate of sea level rise and the loss of sea ice in both northern and southern polar regions.”

One particular concern highlighted is food security. In the words of the report, “exposure of the agriculture sector to climate extremes is threatening to reverse gains made in ending malnutrition.

“New evidence shows a continuing rise in world hunger  after a prolonged decline, according to data compiled by UN agencies including the Food and Agriculture Organization (FAO) and World Food Programme.

“In 2017, the number of undernourished people was estimated to have increased to 821 million, partly due to severe droughts associated with the strong El Niño of 2015–2016.”

Climate refugees

The FAO says the absolute number of undernourished people − those facing chronic food deprivation − reached  nearly 821 m in 2017, from around 804 m in 2016.

The WMO report also singles out the plight of those forced by climate change to leave their homes and become refugees, either within their own countries or abroad. Out of 17.7 m people classified as internally displaced persons (IDPs) tracked by the International Organization for Migration, it says, by September 2018 over 2 m people had been displaced by disasters linked to weather and climate events.

According to the UN refugee agency UNHCR’s Protection and Return Monitoring Network, about 883,000 new internal displacements were recorded between January and December 2018, of which 32% were associated with flooding and 29% with drought.

Hundreds of thousands of Rohingya refugees were affected by what the UN calls “secondary displacement”, caused by extreme events, heavy rain, flooding and landslides.

More acid seas

The WMO also expresses concern about a range of impacts of climate change on the global environment, including reduced levels of oxygen in the oceans. Since the middle of the last century there has been an estimated 1-2% decrease in the amount of oxygen in the world’s oceans, according to UNESCO’s Intergovernmental Oceanographic Commission (UNESCO-IOC).

In the past decade the oceans have absorbed around 30% of CO2 emissions of human origin. Absorbed CO2 reacts with seawater and changes the pH of the ocean. This process, known as ocean acidification, can affect the ability of marine organisms such as molluscs and reef-building corals, to build and maintain shells and skeletal material.

Observations in the open ocean over the last 30 years have shown a clear trend of decreasing pH. In line with previous reports and projections, ocean acidification is ongoing and the global pH levels continue to decrease, according to UNESCO-IOC. One recent report suggested possible alarming future impacts.

The State of the Climate report will be one of WMO’s contributions to the UN’s Climate Action Summit on 23 September. − Climate News Network

Worse tropical winds will kill more trees

More greenhouse gases mean worse tropical winds and fiercer storms. That could mean more forest damage . . . and more greenhouse gas emissions . . .

LONDON, 28 March, 2019 − Worse tropical winds will spell worse danger to forests, in a cycle that feeds on itself. Hurricane Maria, which in 2017 slammed into Puerto Rico, shut down the electricity supply for the entire US island of 3.3 million people, and claimed almost 3,000 lives. And it also killed or damaged at least 20 million trees, or possibly 40 million.

If what happened in the track of Maria is a pointer to the future, then hurricanes, typhoons and tropical cyclones will join drought, wildfire and men with chainsaws as a new threat to the world’s tropical forests, the biggest absorbers of carbon on the terrestrial surface.

Living forests absorb carbon. Dying and decaying trees release greenhouse gases. The damage by Maria has already been estimated to have released 5.75 million tonnes of carbon to the atmosphere. This is about one-fortieth of all the carbon taken up by all the forests in the US.

“The expected changes in hurricane winds and rainfall may have profound consequences for the long-term resilience of tropical forests in the North Atlantic basin”

Hurricanes are linked with rising sea surface temperatures. Researchers have been warning for decades that in a warming world, extremes of heat, drought, flood and windstorm will become more destructive. So Hurricane Maria could be a taste of things to come.

“These hurricanes are going to kill more trees,” said Maria Uriarte, of the Earth Institute of Columbia University. “They’re going to break more trees. The factors that protected many trees in the past will no longer apply. Forests will become shorter and smaller because they won’t have time to regrow, and they will be less diverse.”

Maria blew into Puerto Rico in October 2017, with winds of up to 250 kms an hour. It dropped 500 mm of rain to become the island’s worst storm for 90 years.

To make their estimate of the destruction, Professor Uriarte and colleagues surveyed a 16-hectare plot of the island’s El Yunque national forest near the capital, San Juan: a plot that has been monitored after violent windstorm assault in 1989 by Hurricane Hugo and then in 1998 by Hurricane Georges.

Much fiercer impact

They report in the journal Nature Communications that Hurricane Maria killed twice as many trees outright as previous storms, and snapped more than three times as many trunks. Some species experienced breakage rates of up to 12 times that of previous hurricanes. Among them, and unexpectedly, were some of the slowest-growing, most valuable hardwoods. About half of all trees with broken trunks are expected to die within two or three years.

Some species survived well: among them the sierra palm, a tree able to bend with the wind, and if stripped sprout again from the top. Such species could be the inheritors of future hurricanes and grow quickly to take advantage of cleared forest space. So future forests could be dominated by shorter, and less diverse, foliage.

And the future is unpromising. Atlantic Ocean sea surface temperatures are rising, and climate simulations predict that by 2100 the highest sustained hurricane winds could increase by 15%. Warmer air can hold more moisture, so rainfall near storm centres could increase by 20%. Extreme winds fell trees; rain destabilises soil and makes uprooting easier.

“Maria transformed tropical forests across the island into leafless tangles of damaged and downed trees,” the researchers write. And they warn: “The expected changes in hurricane winds and rainfall may have profound consequences for the long-term resilience of tropical forests in the North Atlantic basin.” − Climate News Network

More greenhouse gases mean worse tropical winds and fiercer storms. That could mean more forest damage . . . and more greenhouse gas emissions . . .

LONDON, 28 March, 2019 − Worse tropical winds will spell worse danger to forests, in a cycle that feeds on itself. Hurricane Maria, which in 2017 slammed into Puerto Rico, shut down the electricity supply for the entire US island of 3.3 million people, and claimed almost 3,000 lives. And it also killed or damaged at least 20 million trees, or possibly 40 million.

If what happened in the track of Maria is a pointer to the future, then hurricanes, typhoons and tropical cyclones will join drought, wildfire and men with chainsaws as a new threat to the world’s tropical forests, the biggest absorbers of carbon on the terrestrial surface.

Living forests absorb carbon. Dying and decaying trees release greenhouse gases. The damage by Maria has already been estimated to have released 5.75 million tonnes of carbon to the atmosphere. This is about one-fortieth of all the carbon taken up by all the forests in the US.

“The expected changes in hurricane winds and rainfall may have profound consequences for the long-term resilience of tropical forests in the North Atlantic basin”

Hurricanes are linked with rising sea surface temperatures. Researchers have been warning for decades that in a warming world, extremes of heat, drought, flood and windstorm will become more destructive. So Hurricane Maria could be a taste of things to come.

“These hurricanes are going to kill more trees,” said Maria Uriarte, of the Earth Institute of Columbia University. “They’re going to break more trees. The factors that protected many trees in the past will no longer apply. Forests will become shorter and smaller because they won’t have time to regrow, and they will be less diverse.”

Maria blew into Puerto Rico in October 2017, with winds of up to 250 kms an hour. It dropped 500 mm of rain to become the island’s worst storm for 90 years.

To make their estimate of the destruction, Professor Uriarte and colleagues surveyed a 16-hectare plot of the island’s El Yunque national forest near the capital, San Juan: a plot that has been monitored after violent windstorm assault in 1989 by Hurricane Hugo and then in 1998 by Hurricane Georges.

Much fiercer impact

They report in the journal Nature Communications that Hurricane Maria killed twice as many trees outright as previous storms, and snapped more than three times as many trunks. Some species experienced breakage rates of up to 12 times that of previous hurricanes. Among them, and unexpectedly, were some of the slowest-growing, most valuable hardwoods. About half of all trees with broken trunks are expected to die within two or three years.

Some species survived well: among them the sierra palm, a tree able to bend with the wind, and if stripped sprout again from the top. Such species could be the inheritors of future hurricanes and grow quickly to take advantage of cleared forest space. So future forests could be dominated by shorter, and less diverse, foliage.

And the future is unpromising. Atlantic Ocean sea surface temperatures are rising, and climate simulations predict that by 2100 the highest sustained hurricane winds could increase by 15%. Warmer air can hold more moisture, so rainfall near storm centres could increase by 20%. Extreme winds fell trees; rain destabilises soil and makes uprooting easier.

“Maria transformed tropical forests across the island into leafless tangles of damaged and downed trees,” the researchers write. And they warn: “The expected changes in hurricane winds and rainfall may have profound consequences for the long-term resilience of tropical forests in the North Atlantic basin.” − Climate News Network

Gulf Stream slowdown may bring later cold

The Gulf Stream is weakening, and Europe could expect a prolonged cold spell as the world warms – but not the day after tomorrow.

LONDON, 25 March, 2019 – As the Gulf Stream weakens in a rapidly warming world, north-western Europe could paradoxically become cooler. There is, however, a time lag between those two climate change-related events, and US scientists now think they know how long that could be.
It could be as much as 400 years.

They know this because the world has warmed and cooled before, and as the difference between tropics and Arctic narrows, there is a change in the so-called Atlantic conveyor, an important part of the climate machine.

This vast Atlantic current carries a steady flow of warm water to the far north, making north-western Europe up to 5°C warmer than its latitude would otherwise dictate. Then, as it meets colder, denser Arctic waters, it dives, to carry its burden of surface carbon to the depths, and then flows southwards again.

This phenomenon, known as the Atlantic Meridional Overturning Circulation, or AMOC, is in effect Europe’s bespoke heating system: Britain’s chief scientific adviser once calculated that it delivers to the UK alone the warmth of 27,000 power stations.

“There are some precursors in the ocean, so we should be watching the ocean”

But evidence from climate history shows that this heating has been turned off a number of times. Europe was plunged into a cold snap 13,000 years ago during a period known as the Younger Dryas and then warmed up about 11,000 years ago.

New and sophisticated studies of fossil carbon show that anybody taking notes at the time might have observed the warning signs. About 400 years before the abrupt shift to a frosty spell, the Atlantic current weakened. And it started to strengthen again about four centuries before the world warmed.

The study, published in the journal Nature Communications, confirms what climate scientists have always known: any sudden catastrophic return of the Ice Ages – dramatised in Hollywood’s notorious 2004 climate change movie The Day After Tomorrow – won’t happen at action movie pace. But it will happen over decades, and now seemingly with several centuries of advance notice.

“Our reconstructions indicate that there are clear climate precursors provided by the ocean state – like warning signs, so to speak,” said Francesco Muschitiello, then of the Lamont-Doherty Earth Observatory at Columbia University, US, and now at the University of Cambridge in the UK, who led the research.

Timing established

Climate scientists have clear dates for the timing of the Younger Dryas event: ice cores from the Arctic show both that Greenland’s temperature fell by 6°C or more at the beginning of the cycle, and that it rose by at least 8°C at its end.

To time the changes in the ocean current, they used carbon-dating techniques to identify a pattern of change in the marine sediments in the Norwegian Sea.

Since marine sediments settle very slowly, over very long periods of time, they needed a more precise “clock” to help calibrate their calculations: they found this in the fossilised ancient plants in a Scandinavian lake.

The isotope carbon-14 is pulled directly from the atmosphere each season by growing foliage. It decays at a predictable rate, and the amount of surviving C14 delivered a reliable clock. The identification of two volcanic ash layers from eruptions in Iceland, in both lake and seabed, provided yet more confidence in the timings. From these factors, the researchers were able to identify a slowdown in the transport of carbon from surface to the deep – and thus a slowdown in the current.

Long wait

The research confirms a link between ocean circulation patterns and northern hemisphere climate shifts: it provides evidence of what could be a considerable interval between the two.

Researchers have repeatedly warned that the Atlantic current seemed to be slowing, in response to global warming driven by profligate fossil fuel use by humankind, and that the consequences of continued slowdown could be very uncomfortable for hundreds of millions.

If the evidence from the Younger Dryas provides a sure parallel to today’s conditions, then Europeans might have time to prepare.

“It is clear that there are some precursors in the ocean, so we should be watching the ocean,” said Dr Muschitiello. “The mere fact that AMOC has been slowing down, that should be a concern based on what we have found.” – Climate News Network

The Gulf Stream is weakening, and Europe could expect a prolonged cold spell as the world warms – but not the day after tomorrow.

LONDON, 25 March, 2019 – As the Gulf Stream weakens in a rapidly warming world, north-western Europe could paradoxically become cooler. There is, however, a time lag between those two climate change-related events, and US scientists now think they know how long that could be.
It could be as much as 400 years.

They know this because the world has warmed and cooled before, and as the difference between tropics and Arctic narrows, there is a change in the so-called Atlantic conveyor, an important part of the climate machine.

This vast Atlantic current carries a steady flow of warm water to the far north, making north-western Europe up to 5°C warmer than its latitude would otherwise dictate. Then, as it meets colder, denser Arctic waters, it dives, to carry its burden of surface carbon to the depths, and then flows southwards again.

This phenomenon, known as the Atlantic Meridional Overturning Circulation, or AMOC, is in effect Europe’s bespoke heating system: Britain’s chief scientific adviser once calculated that it delivers to the UK alone the warmth of 27,000 power stations.

“There are some precursors in the ocean, so we should be watching the ocean”

But evidence from climate history shows that this heating has been turned off a number of times. Europe was plunged into a cold snap 13,000 years ago during a period known as the Younger Dryas and then warmed up about 11,000 years ago.

New and sophisticated studies of fossil carbon show that anybody taking notes at the time might have observed the warning signs. About 400 years before the abrupt shift to a frosty spell, the Atlantic current weakened. And it started to strengthen again about four centuries before the world warmed.

The study, published in the journal Nature Communications, confirms what climate scientists have always known: any sudden catastrophic return of the Ice Ages – dramatised in Hollywood’s notorious 2004 climate change movie The Day After Tomorrow – won’t happen at action movie pace. But it will happen over decades, and now seemingly with several centuries of advance notice.

“Our reconstructions indicate that there are clear climate precursors provided by the ocean state – like warning signs, so to speak,” said Francesco Muschitiello, then of the Lamont-Doherty Earth Observatory at Columbia University, US, and now at the University of Cambridge in the UK, who led the research.

Timing established

Climate scientists have clear dates for the timing of the Younger Dryas event: ice cores from the Arctic show both that Greenland’s temperature fell by 6°C or more at the beginning of the cycle, and that it rose by at least 8°C at its end.

To time the changes in the ocean current, they used carbon-dating techniques to identify a pattern of change in the marine sediments in the Norwegian Sea.

Since marine sediments settle very slowly, over very long periods of time, they needed a more precise “clock” to help calibrate their calculations: they found this in the fossilised ancient plants in a Scandinavian lake.

The isotope carbon-14 is pulled directly from the atmosphere each season by growing foliage. It decays at a predictable rate, and the amount of surviving C14 delivered a reliable clock. The identification of two volcanic ash layers from eruptions in Iceland, in both lake and seabed, provided yet more confidence in the timings. From these factors, the researchers were able to identify a slowdown in the transport of carbon from surface to the deep – and thus a slowdown in the current.

Long wait

The research confirms a link between ocean circulation patterns and northern hemisphere climate shifts: it provides evidence of what could be a considerable interval between the two.

Researchers have repeatedly warned that the Atlantic current seemed to be slowing, in response to global warming driven by profligate fossil fuel use by humankind, and that the consequences of continued slowdown could be very uncomfortable for hundreds of millions.

If the evidence from the Younger Dryas provides a sure parallel to today’s conditions, then Europeans might have time to prepare.

“It is clear that there are some precursors in the ocean, so we should be watching the ocean,” said Dr Muschitiello. “The mere fact that AMOC has been slowing down, that should be a concern based on what we have found.” – Climate News Network

Ocean heatwaves drive more fish north

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

Oceanic carbon uptake could falter

What does oceanic carbon uptake achieve? Greenhouse gas that sinks below the waves slows global warming a little and makes the water more acidic.

LONDON, 20 March, 2019 − Scientists can now put a measure to the role of the waves as a climate shock absorber: they estimate that oceanic carbon uptake by the deep blue seas has consumed 34 billion tonnes of man-made carbon from the atmosphere between the years 1994 and 2007.

This is just about 31% of all the carbon emitted in that time by car exhausts, power station chimneys, aircraft, ships, tractors and scorched forest, as human economies expand and ever more fossil fuel is consumed.

This confident figure is based on a global survey of the chemistry and other physical properties of the ocean by scientists from seven nations on more than 50 research cruises, taking measurements of the ocean from the surface to a depth of six kilometres.

The researchers report in the journal Science that they already had the results of a global carbon survey of the oceans conducted at the close of the last century, and had calculated that from the dawn of the Industrial Revolution – when humans started using coal, and then oil and gas – to 1994, the oceans had already absorbed 118 billion tonnes.

“The marine sink does not just respond to the increase in atmospheric CO2. Its substantial sensitivity to climate variations suggests a significant potential for feedbacks”

For the latest exercise, they developed a statistical tool that helped them make the distinction between the man-made and the natural atmospheric carbon dioxide always found dissolved in water.

The good news is that the ocean remains for the moment a stable component of the planet’s carbon budget: overall, as more man-made carbon is emitted from exhausts and chimneys, the ocean takes up proportionally more.

The bad news is that this may not go on for ever. At some point, the planet’s seas could become saturated with carbon, leaving ever more in the atmosphere to accelerate global warming to ever more alarming temperatures.

And there is a second unhappy consequence: the more carbon dioxide absorbed by the oceans, the more the sea shifts towards a weak solution of carbonic acid, with potentially calamitous consequences both for marine life and for commercial fisheries.

Research like this is essentially of academic interest: it adds precision to the big picture of a vast ocean that absorbs carbon dioxide, and overturning currents that take it to great depths, and out of atmospheric circulation.

An active moderator

But it is also a reminder that the ocean plays an active role in moderating planetary temperatures, absorbing ever greater quantities of heat and responding with fiercer levels of energy.

It also confirms that although, on average, the high seas are responding to atmospheric change as expected, different ocean basins can vary: the North Atlantic actually absorbed 20% less CO2 than expected between 1994 and 2007, probably thanks to the slowing of the North Atlantic Meridional Overturning Circulation at the time.

And, the researchers say, the acidification of the oceans is on the increase, to depths of 3000 metres. The next step is to understand a little better the interplay between ocean, atmosphere and human emissions of greenhouse gases.

“We learned that the marine sink does not just respond to the increase in atmospheric CO2,” said Nicolas Gruber of the Swiss Federal Institute of Technology, always known as ETH Zurich, who led the study.

“Its substantial sensitivity to climate variations suggests a significant potential for feedbacks with the ongoing change in climate.” − Climate News Network

What does oceanic carbon uptake achieve? Greenhouse gas that sinks below the waves slows global warming a little and makes the water more acidic.

LONDON, 20 March, 2019 − Scientists can now put a measure to the role of the waves as a climate shock absorber: they estimate that oceanic carbon uptake by the deep blue seas has consumed 34 billion tonnes of man-made carbon from the atmosphere between the years 1994 and 2007.

This is just about 31% of all the carbon emitted in that time by car exhausts, power station chimneys, aircraft, ships, tractors and scorched forest, as human economies expand and ever more fossil fuel is consumed.

This confident figure is based on a global survey of the chemistry and other physical properties of the ocean by scientists from seven nations on more than 50 research cruises, taking measurements of the ocean from the surface to a depth of six kilometres.

The researchers report in the journal Science that they already had the results of a global carbon survey of the oceans conducted at the close of the last century, and had calculated that from the dawn of the Industrial Revolution – when humans started using coal, and then oil and gas – to 1994, the oceans had already absorbed 118 billion tonnes.

“The marine sink does not just respond to the increase in atmospheric CO2. Its substantial sensitivity to climate variations suggests a significant potential for feedbacks”

For the latest exercise, they developed a statistical tool that helped them make the distinction between the man-made and the natural atmospheric carbon dioxide always found dissolved in water.

The good news is that the ocean remains for the moment a stable component of the planet’s carbon budget: overall, as more man-made carbon is emitted from exhausts and chimneys, the ocean takes up proportionally more.

The bad news is that this may not go on for ever. At some point, the planet’s seas could become saturated with carbon, leaving ever more in the atmosphere to accelerate global warming to ever more alarming temperatures.

And there is a second unhappy consequence: the more carbon dioxide absorbed by the oceans, the more the sea shifts towards a weak solution of carbonic acid, with potentially calamitous consequences both for marine life and for commercial fisheries.

Research like this is essentially of academic interest: it adds precision to the big picture of a vast ocean that absorbs carbon dioxide, and overturning currents that take it to great depths, and out of atmospheric circulation.

An active moderator

But it is also a reminder that the ocean plays an active role in moderating planetary temperatures, absorbing ever greater quantities of heat and responding with fiercer levels of energy.

It also confirms that although, on average, the high seas are responding to atmospheric change as expected, different ocean basins can vary: the North Atlantic actually absorbed 20% less CO2 than expected between 1994 and 2007, probably thanks to the slowing of the North Atlantic Meridional Overturning Circulation at the time.

And, the researchers say, the acidification of the oceans is on the increase, to depths of 3000 metres. The next step is to understand a little better the interplay between ocean, atmosphere and human emissions of greenhouse gases.

“We learned that the marine sink does not just respond to the increase in atmospheric CO2,” said Nicolas Gruber of the Swiss Federal Institute of Technology, always known as ETH Zurich, who led the study.

“Its substantial sensitivity to climate variations suggests a significant potential for feedbacks with the ongoing change in climate.” − Climate News Network

More acidic seas devour marine food web

As more acidic seas spread across the globe, conditions for survival start to change. That could close vast volumes of ocean for vital forms of life.

LONDON, 13 March, 2019 – By the close of the century, parts of the Southern Ocean could become impoverished as more acidic seas displace abundant marine food resources. Tiny sea snails that form the basis of the food supply for one of the world’s richest ecosystems could disappear because the depth at which they can form their shells will have shifted.

Right now, in Antarctic waters, creatures known as pteropods can exploit the calcium carbonate dissolved in the oceans down to a depth of 1000 metres to grow their shells.

But as atmospheric carbon dioxide levels soar, as a consequence of profligate use of fossil fuels by humankind, the chemistry of the oceans will shift towards the acidic.

The ratios of two kinds of carbonate – calcite and aragonite – will alter. And by 2100, there won’t be enough aragonite.

“A pocket of corrosive water will sit just below the surface, making life difficult for these communities of primarily surface-dwelling organisms”

Right now, pteropods flourish in the top 300 metres of the ocean. By 2100, the survival zone for the pteropods will end at a depth of 83 metres.

And, scientists warn in the journal Nature Climate Change, this could “change food web dynamics and have cascading effects on global ocean ecosystems.” In other words, the larger fish and marine mammals that feed on the smaller creatures that in turn depend on a basic diet of pteropods will have nothing to eat.

And that can only be bad news for global fisheries.

All shelled marine creatures – the tiny coccolithophores that die and leave their shells as chalk, the clams and molluscs, the foraminifera that float on the surface or coat the rocks and the seafloor, and the corals that are the basis for rich tropical ecosystems, all depend on the right levels of calcite and aragonite to form their exoskeletons.

The oceans are the biggest living space on the planet: the waves cover 70% of all living space and the depth of the deepest trenches is far greater than the highest terrestrial mountain ranges.

Origin of life

The oceans are the crucible in which life first emerged, and the oceans ultimately provided the sediments from which humankind has built its cities.

US and Norwegian scientists chose one species with precise needs in one reach of ocean as an indicator or what climate change driven by ever greater levels of the greenhouse gas carbon dioxide could do to an ocean ecosystem.

They found that what they called the “aragonite saturation horizon” became dramatically shallower as the seas became more acidic.

“These calcifying organisms will struggle to build and maintain their shells as acidification proceeds,” said Nicole Lovenduski, of the University of Colorado at Boulder, one of the researchers.

Inevitable result

“In the future, a pocket of corrosive water will sit just below the surface, making life difficult for these communities of primarily surface-dwelling organisms.”

As the world warms, acidification of the oceans becomes inevitable. Researchers have repeatedly warned that such change can only diminish ocean life, harm the coral reefs and kelp forests that shelter the rich biodiversity of sea creatures, change the behaviour of fish and some kinds of shrimp and threaten the shellfish harvest.

But for the first time, scientists have been able to model the impact of atmospheric change on the ocean chemistry in one zone at precise depths. The message is that right now, the pteropods have plenty of sea space for survival. But the aragonite saturation horizon may have already begun to shift in some places: perhaps as early as 2006, or as late as 2038. Once change begins, it will continue.

“If emissions were curbed tomorrow, this suddenly shallow horizon would still appear, even if possibly delayed,” said Dr Lovenduski. “And that, inevitably, along with lack of time for organisms to adapt, is most concerning.” – Climate News Network

As more acidic seas spread across the globe, conditions for survival start to change. That could close vast volumes of ocean for vital forms of life.

LONDON, 13 March, 2019 – By the close of the century, parts of the Southern Ocean could become impoverished as more acidic seas displace abundant marine food resources. Tiny sea snails that form the basis of the food supply for one of the world’s richest ecosystems could disappear because the depth at which they can form their shells will have shifted.

Right now, in Antarctic waters, creatures known as pteropods can exploit the calcium carbonate dissolved in the oceans down to a depth of 1000 metres to grow their shells.

But as atmospheric carbon dioxide levels soar, as a consequence of profligate use of fossil fuels by humankind, the chemistry of the oceans will shift towards the acidic.

The ratios of two kinds of carbonate – calcite and aragonite – will alter. And by 2100, there won’t be enough aragonite.

“A pocket of corrosive water will sit just below the surface, making life difficult for these communities of primarily surface-dwelling organisms”

Right now, pteropods flourish in the top 300 metres of the ocean. By 2100, the survival zone for the pteropods will end at a depth of 83 metres.

And, scientists warn in the journal Nature Climate Change, this could “change food web dynamics and have cascading effects on global ocean ecosystems.” In other words, the larger fish and marine mammals that feed on the smaller creatures that in turn depend on a basic diet of pteropods will have nothing to eat.

And that can only be bad news for global fisheries.

All shelled marine creatures – the tiny coccolithophores that die and leave their shells as chalk, the clams and molluscs, the foraminifera that float on the surface or coat the rocks and the seafloor, and the corals that are the basis for rich tropical ecosystems, all depend on the right levels of calcite and aragonite to form their exoskeletons.

The oceans are the biggest living space on the planet: the waves cover 70% of all living space and the depth of the deepest trenches is far greater than the highest terrestrial mountain ranges.

Origin of life

The oceans are the crucible in which life first emerged, and the oceans ultimately provided the sediments from which humankind has built its cities.

US and Norwegian scientists chose one species with precise needs in one reach of ocean as an indicator or what climate change driven by ever greater levels of the greenhouse gas carbon dioxide could do to an ocean ecosystem.

They found that what they called the “aragonite saturation horizon” became dramatically shallower as the seas became more acidic.

“These calcifying organisms will struggle to build and maintain their shells as acidification proceeds,” said Nicole Lovenduski, of the University of Colorado at Boulder, one of the researchers.

Inevitable result

“In the future, a pocket of corrosive water will sit just below the surface, making life difficult for these communities of primarily surface-dwelling organisms.”

As the world warms, acidification of the oceans becomes inevitable. Researchers have repeatedly warned that such change can only diminish ocean life, harm the coral reefs and kelp forests that shelter the rich biodiversity of sea creatures, change the behaviour of fish and some kinds of shrimp and threaten the shellfish harvest.

But for the first time, scientists have been able to model the impact of atmospheric change on the ocean chemistry in one zone at precise depths. The message is that right now, the pteropods have plenty of sea space for survival. But the aragonite saturation horizon may have already begun to shift in some places: perhaps as early as 2006, or as late as 2038. Once change begins, it will continue.

“If emissions were curbed tomorrow, this suddenly shallow horizon would still appear, even if possibly delayed,” said Dr Lovenduski. “And that, inevitably, along with lack of time for organisms to adapt, is most concerning.” – Climate News Network

Paris climate pledge would help world fishing

Honouring the Paris climate pledge would provide a fair catch for the world’s fishing fleets. Warm up the oceans, though, and everyone loses.

LONDON, 12 March, 2019 – Canadian scientists have worked out the way to make the most of the world’s fish stocks: by honouring the Paris climate pledge.

Seagoing nations could raise revenues for their fishing fleets, put more seafood on the table and protect the most valuable commercial fish stocks simply by doing what they had promised in 2015 to do anyway.

The key is the historic agreement reached then in Paris by 195 nations, to take steps to limit average global warming to “well below” a total of 2°C above the long-term average for most of human history, and to do this by 2100.

In the last century or so the global temperature has already risen by around 1°C, as a consequence of ever-increasing combustion of fossil fuels that emit greenhouse gases into the atmosphere.

“The largest gains will occur in developing country waters … which are at the greatest risk due to warming temperatures”

But although the world agreed its ideal target, the action so far leaves it on course for a potentially catastrophic rise of 3.5°C by the end of the century.

“Achieving the Agreement’s target could increase global fisheries revenues by $4.6 billion annually, seafood workers’ income by $3.7 bn and reduce household seafood expenditures by $5.4 bn,” said Rashid Sumaila, of the University of British Columbia’s Institute for Oceans and Fisheries.

“The largest gains will occur in developing country waters, such as Kiribati, the Maldives and Indonesia, which are at the greatest risk due to warming temperatures and rely the most on fish for food security, incomes and employment.”

What the researchers did – they explain their approach in the journal Science Advances – was to match what the computer forecasts said the Paris target would deliver, with what might happen if the world went on burning oil, coal and gas under the notorious business-as-usual scenario.

Impacts on ecosystems

They looked at the impact of less or more warming on 381 marine species, including the 10 that generate the most money, and they included ecosystem consequences as well as the economic payoff promised by the Paris target.

Their conclusion is that three-fourths of maritime countries would benefit, with the largest gains to be made by the developing nations.

Under the Paris scenario, the total mass of the fish species that generate the highest revenues would increase globally by 6.5%, with an 8.4% increase in the waters of developing countries. Overall, developed countries would see a marginal fall of 0.4%.

The Paris option would see an additional 3.3 million tonnes landed sustainably every year, compared with the business-as-usual scenario.

Conservation also needed

The British Columbia scientists are not the first to make the case for Paris in terms of fishery revenues: US and Japanese scientists looked at the same problem last year and concluded that the Paris option – matched by careful conservation approaches – could yield more fish for the hungry, and more revenues for the fishermen, if the ocean temperatures were kept from rising too dangerously.

But all the signals so far are ominous. A warmer world means a stormier one and greater danger for fishing fleets. More carbon dioxide in the atmosphere means ever more acidic seas, which seems to affect fish behaviour and threaten marine habitats such as coral reefs and kelp forests.

The same rise in carbon dioxide will warm the oceans and drive fish to migrate. Overall, humans have already left the seas diminished, and worse could be on the way. Fishing and seafood support an estimated 260 million full-time and part-time jobs worldwide.

Many to benefit

The Science Advances study is a reminder that while change is inexorable, the worst need not be inevitable. All continents except Europe would benefit from implementation of the Paris Agreement.

But as fish move towards the poles, countries in northern Europe might benefit from greater choice in their waters, and losses in the overall catch might be buffered by hjgher prices for those fish actually landed.

Russia could see catches reduced by as much as 25% under the 1.5°C target rather than the 3.5°C forecast. “However a projected 19% increase in fish prices, known as the price effect, should result in a negligible loss of less than 2% in fisheries revenues in Russia,” said William Cheung, one of the co-authors, of the University of British Columbia.

“Conversely, for the US fishing revenues are expected to decrease by 8% due to price effects but will be offset by a 21% increase in catch potential.” – Climate News Network

Honouring the Paris climate pledge would provide a fair catch for the world’s fishing fleets. Warm up the oceans, though, and everyone loses.

LONDON, 12 March, 2019 – Canadian scientists have worked out the way to make the most of the world’s fish stocks: by honouring the Paris climate pledge.

Seagoing nations could raise revenues for their fishing fleets, put more seafood on the table and protect the most valuable commercial fish stocks simply by doing what they had promised in 2015 to do anyway.

The key is the historic agreement reached then in Paris by 195 nations, to take steps to limit average global warming to “well below” a total of 2°C above the long-term average for most of human history, and to do this by 2100.

In the last century or so the global temperature has already risen by around 1°C, as a consequence of ever-increasing combustion of fossil fuels that emit greenhouse gases into the atmosphere.

“The largest gains will occur in developing country waters … which are at the greatest risk due to warming temperatures”

But although the world agreed its ideal target, the action so far leaves it on course for a potentially catastrophic rise of 3.5°C by the end of the century.

“Achieving the Agreement’s target could increase global fisheries revenues by $4.6 billion annually, seafood workers’ income by $3.7 bn and reduce household seafood expenditures by $5.4 bn,” said Rashid Sumaila, of the University of British Columbia’s Institute for Oceans and Fisheries.

“The largest gains will occur in developing country waters, such as Kiribati, the Maldives and Indonesia, which are at the greatest risk due to warming temperatures and rely the most on fish for food security, incomes and employment.”

What the researchers did – they explain their approach in the journal Science Advances – was to match what the computer forecasts said the Paris target would deliver, with what might happen if the world went on burning oil, coal and gas under the notorious business-as-usual scenario.

Impacts on ecosystems

They looked at the impact of less or more warming on 381 marine species, including the 10 that generate the most money, and they included ecosystem consequences as well as the economic payoff promised by the Paris target.

Their conclusion is that three-fourths of maritime countries would benefit, with the largest gains to be made by the developing nations.

Under the Paris scenario, the total mass of the fish species that generate the highest revenues would increase globally by 6.5%, with an 8.4% increase in the waters of developing countries. Overall, developed countries would see a marginal fall of 0.4%.

The Paris option would see an additional 3.3 million tonnes landed sustainably every year, compared with the business-as-usual scenario.

Conservation also needed

The British Columbia scientists are not the first to make the case for Paris in terms of fishery revenues: US and Japanese scientists looked at the same problem last year and concluded that the Paris option – matched by careful conservation approaches – could yield more fish for the hungry, and more revenues for the fishermen, if the ocean temperatures were kept from rising too dangerously.

But all the signals so far are ominous. A warmer world means a stormier one and greater danger for fishing fleets. More carbon dioxide in the atmosphere means ever more acidic seas, which seems to affect fish behaviour and threaten marine habitats such as coral reefs and kelp forests.

The same rise in carbon dioxide will warm the oceans and drive fish to migrate. Overall, humans have already left the seas diminished, and worse could be on the way. Fishing and seafood support an estimated 260 million full-time and part-time jobs worldwide.

Many to benefit

The Science Advances study is a reminder that while change is inexorable, the worst need not be inevitable. All continents except Europe would benefit from implementation of the Paris Agreement.

But as fish move towards the poles, countries in northern Europe might benefit from greater choice in their waters, and losses in the overall catch might be buffered by hjgher prices for those fish actually landed.

Russia could see catches reduced by as much as 25% under the 1.5°C target rather than the 3.5°C forecast. “However a projected 19% increase in fish prices, known as the price effect, should result in a negligible loss of less than 2% in fisheries revenues in Russia,” said William Cheung, one of the co-authors, of the University of British Columbia.

“Conversely, for the US fishing revenues are expected to decrease by 8% due to price effects but will be offset by a 21% increase in catch potential.” – Climate News Network