Tag Archives: Australia

Kelp forests under threat from acid seas

The kelp forests – those towering submarine tangles of brown seaweeds – may not survive the steady change of ocean chemistry.

LONDON, 17 May, 2018 – Australian scientists have identified a risk to the kelp forests of the oceans, a new way in which carbon dioxide can change the world. Ever more acidic oceans could encourage weedy submarine grasslands to replace the rich habitats of the coastal kelp forests.

Although most climate change forecasts are based on computer simulation, this one has been tested in the real world. The scientists used natural volcanic seeps rich in carbon dioxide to observe the changes to sea floor ecosystems as water chemistry changes with greater levels of dissolved CO2.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally,” said Sean Connell, of the Environment Institute at the University of Adelaide.

“Weedy species are quicker to capitalise on nutrients, such as carbon, and can grow faster than their natural predators can consume them.

Weedy turf wins

“Unfortunately, the CO2 that humans are pumping into the atmosphere by burning fossil fuels gets absorbed by the ocean and favours weedy turfs, which replace kelp forests that support higher coastal productivity and biodiversity.”

He and colleagues from Australia, the US, New Zealand, Italy and Hong Kong report in the journal Ecology that they made a series of samples of submarine plant growth at natural volcanic vents in New Zealand’s Bay of Plenty: they looked at rocky reefs on which grew a mosaic of kelp and turf algae, along barren stretches grazed by sea urchins and a native New Zealand mollusc.

They chose the sites because the levels of carbon dioxide – and therefore the measures of acidity – in the water were roughly what climate scientists would predict for the end of this century, if humans go on releasing greenhouse gases.

They found that ecosystems changed with shifts in water chemistry. “While elevated CO2 caused some weeds to be eaten in greater amounts, the dominant sea urchin predator ate these weeds at reduced amounts. This enabled the weeds to escape their natural controls and expand across coasts near the elevated CO2,” Professor Connell said.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally”

The slow but inexorable changes in ocean acidity will have inevitable consequences for coastal protection offered by natural ecosystems. Kelp forests provide habitat or nourishment for seals, sea otters, sea lions, whales, cormorants, gulls, terns and shore birds as well as fish. There is evidence that warming has already damaged some of Australia’s kelp forests.

Researchers have been issuing such warnings for years: among them Professor Connell and his co-author from Adelaide, Ivan Nagelkerken, who, three years ago, surveyed 632 scientific studies of a huge range of marine habitats to conclude that the overall effect of acidification was to impoverish ocean life.

“Under the level of acidification we will find in the oceans in a few decades, marine life is likely to be dominated by fast-growing and opportunistic species at the expense of longer-lived species with specialist lifestyles, unless we set some change in place,” said Professor Nagelkerken.

“We need to consider how natural enemies might be managed so that those weedy species are kept under control.” – Climate News Network

The kelp forests – those towering submarine tangles of brown seaweeds – may not survive the steady change of ocean chemistry.

LONDON, 17 May, 2018 – Australian scientists have identified a risk to the kelp forests of the oceans, a new way in which carbon dioxide can change the world. Ever more acidic oceans could encourage weedy submarine grasslands to replace the rich habitats of the coastal kelp forests.

Although most climate change forecasts are based on computer simulation, this one has been tested in the real world. The scientists used natural volcanic seeps rich in carbon dioxide to observe the changes to sea floor ecosystems as water chemistry changes with greater levels of dissolved CO2.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally,” said Sean Connell, of the Environment Institute at the University of Adelaide.

“Weedy species are quicker to capitalise on nutrients, such as carbon, and can grow faster than their natural predators can consume them.

Weedy turf wins

“Unfortunately, the CO2 that humans are pumping into the atmosphere by burning fossil fuels gets absorbed by the ocean and favours weedy turfs, which replace kelp forests that support higher coastal productivity and biodiversity.”

He and colleagues from Australia, the US, New Zealand, Italy and Hong Kong report in the journal Ecology that they made a series of samples of submarine plant growth at natural volcanic vents in New Zealand’s Bay of Plenty: they looked at rocky reefs on which grew a mosaic of kelp and turf algae, along barren stretches grazed by sea urchins and a native New Zealand mollusc.

They chose the sites because the levels of carbon dioxide – and therefore the measures of acidity – in the water were roughly what climate scientists would predict for the end of this century, if humans go on releasing greenhouse gases.

They found that ecosystems changed with shifts in water chemistry. “While elevated CO2 caused some weeds to be eaten in greater amounts, the dominant sea urchin predator ate these weeds at reduced amounts. This enabled the weeds to escape their natural controls and expand across coasts near the elevated CO2,” Professor Connell said.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally”

The slow but inexorable changes in ocean acidity will have inevitable consequences for coastal protection offered by natural ecosystems. Kelp forests provide habitat or nourishment for seals, sea otters, sea lions, whales, cormorants, gulls, terns and shore birds as well as fish. There is evidence that warming has already damaged some of Australia’s kelp forests.

Researchers have been issuing such warnings for years: among them Professor Connell and his co-author from Adelaide, Ivan Nagelkerken, who, three years ago, surveyed 632 scientific studies of a huge range of marine habitats to conclude that the overall effect of acidification was to impoverish ocean life.

“Under the level of acidification we will find in the oceans in a few decades, marine life is likely to be dominated by fast-growing and opportunistic species at the expense of longer-lived species with specialist lifestyles, unless we set some change in place,” said Professor Nagelkerken.

“We need to consider how natural enemies might be managed so that those weedy species are kept under control.” – Climate News Network

Hopes rise for some coral survival

US scientists have good news about prospects for coral survival on one of the world’s great reefs, threatened by climate change.

LONDON, 25 April, 2018 – Researchers have raised hopes that limited coral survival may be possible, allowing one of the world’s best-known reefs to survive a little longer.

Although corals are highly sensitive to ocean warming, and notoriously bleach when temperatures exceed a certain limit, a new study has shown that at least one coral can evolve tolerance to excessive temperatures.

The implication is that even though other teams have repeatedly warned that the world’s reefs are in peril as the world warms because of ever-greater ratios of greenhouse gases in the atmosphere, as a consequence of human combustion of fossil fuels at a profligate rate, the world’s great reefs may survive for perhaps another century, rather than perish within the next 50 years.

“It means these corals will still go extinct if we do nothing,” said Misha Matz, of the University of Texas at Austin, who led the study. “But it also means we have a chance to save them. It buys us time to actually do something about global warming, which is the main problem.”

The argument is based on Darwinian logic: coral colonies produce colossal numbers of larvae each year, set adrift on ocean currents to colonise new reefs. As conditions change, those corals that by an accident of genetic inheritance have the traits needed to cope with environmental challenge will get a foothold, and flourish. Those that don’t will fade out. Natural selection will respond.

”While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers”

And this is hopeful news, if only because the world’s reefs are under threat as never before. Bleaching – the response to heat in which coral rejects the algae with which it normally lives in symbiosis – has always happened: research earlier this year suggests it could become five times more frequent, and reefs such as Australia’s Great Barrier would have no time to recover.

Some reefs have already been pronounced too damaged ever to be restored. This is bad news not just for the coral animals: the tropical reefs are just about the richest habitats on the planet, and of profound economic importance to humans too.

A partnership of US and Australian scientists reports in the Public Library of Science journal PLOS Genetics that computer simulation models and genetic evidence of variation from one species of staghorn coral, called Acropora millepora, together show that the coral could in theory adapt over a stretch of 20 to 50 generations.

“This genetic variation is like fuel for natural selection,” Dr Matz said. “If there is enough of it, evolution can be remarkably fast, because all it needs to do is reshuffle the existing variants between the populations.

“It doesn’t have to wait for a new mutation to appear; it’s already there. The problem is, when the genetic variation is exhausted, it is over and the future is unclear.”

Tentative conclusions

There are problems with such studies. This one is based on genetic evidence from one species of coral. But the 2,300 km Great Barrier Reef of Australia is home to at least 411 species of hard coral. It is based on a mathematical model, not on observed change in the reefs.

And global warming is not the only challenge to coral reefs, which are also threatened by human exploitation, pollution and increasing acidification  of the surrounding seas, again as a consequence of ever higher levels of carbon dioxide in the atmosphere.

“Corals live in a symbiotic relationship with zooxanthellae, which are plant-like cells hosted in surface tissues that provide up to 90% of the energy to the colony,” said Stephen Simpson, a marine biologist at the University of Exeter in the UK, commenting on the study.

“Whether there is also sufficient genotypic variation in the zooxanthellae to tolerate further warming remains to be seen. While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers, threatening the functional integrity of reef ecosystems.” – Climate News Network

US scientists have good news about prospects for coral survival on one of the world’s great reefs, threatened by climate change.

LONDON, 25 April, 2018 – Researchers have raised hopes that limited coral survival may be possible, allowing one of the world’s best-known reefs to survive a little longer.

Although corals are highly sensitive to ocean warming, and notoriously bleach when temperatures exceed a certain limit, a new study has shown that at least one coral can evolve tolerance to excessive temperatures.

The implication is that even though other teams have repeatedly warned that the world’s reefs are in peril as the world warms because of ever-greater ratios of greenhouse gases in the atmosphere, as a consequence of human combustion of fossil fuels at a profligate rate, the world’s great reefs may survive for perhaps another century, rather than perish within the next 50 years.

“It means these corals will still go extinct if we do nothing,” said Misha Matz, of the University of Texas at Austin, who led the study. “But it also means we have a chance to save them. It buys us time to actually do something about global warming, which is the main problem.”

The argument is based on Darwinian logic: coral colonies produce colossal numbers of larvae each year, set adrift on ocean currents to colonise new reefs. As conditions change, those corals that by an accident of genetic inheritance have the traits needed to cope with environmental challenge will get a foothold, and flourish. Those that don’t will fade out. Natural selection will respond.

”While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers”

And this is hopeful news, if only because the world’s reefs are under threat as never before. Bleaching – the response to heat in which coral rejects the algae with which it normally lives in symbiosis – has always happened: research earlier this year suggests it could become five times more frequent, and reefs such as Australia’s Great Barrier would have no time to recover.

Some reefs have already been pronounced too damaged ever to be restored. This is bad news not just for the coral animals: the tropical reefs are just about the richest habitats on the planet, and of profound economic importance to humans too.

A partnership of US and Australian scientists reports in the Public Library of Science journal PLOS Genetics that computer simulation models and genetic evidence of variation from one species of staghorn coral, called Acropora millepora, together show that the coral could in theory adapt over a stretch of 20 to 50 generations.

“This genetic variation is like fuel for natural selection,” Dr Matz said. “If there is enough of it, evolution can be remarkably fast, because all it needs to do is reshuffle the existing variants between the populations.

“It doesn’t have to wait for a new mutation to appear; it’s already there. The problem is, when the genetic variation is exhausted, it is over and the future is unclear.”

Tentative conclusions

There are problems with such studies. This one is based on genetic evidence from one species of coral. But the 2,300 km Great Barrier Reef of Australia is home to at least 411 species of hard coral. It is based on a mathematical model, not on observed change in the reefs.

And global warming is not the only challenge to coral reefs, which are also threatened by human exploitation, pollution and increasing acidification  of the surrounding seas, again as a consequence of ever higher levels of carbon dioxide in the atmosphere.

“Corals live in a symbiotic relationship with zooxanthellae, which are plant-like cells hosted in surface tissues that provide up to 90% of the energy to the colony,” said Stephen Simpson, a marine biologist at the University of Exeter in the UK, commenting on the study.

“Whether there is also sufficient genotypic variation in the zooxanthellae to tolerate further warming remains to be seen. While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers, threatening the functional integrity of reef ecosystems.” – Climate News Network

Coral reefs face infection risk from plastic

Plastic flotsam provides a liferaft for deadly bacteria – and a way of colonising coral reefs with killer infections.

LONDON, 29 January, 2018 – Scientists have established yet another hazard from the millions of tons of plastic waste that tip into the sea: it delivers microbial infection to the world’s coral reefs.

When plastic pollutants snag on coral reefs, the likelihood of disease rises from 4% to 89%, they calculate. That is an increase in risk of more than twentyfold.

And the impact on the world’s reefs – already under increasing hazard from ocean acidification and from bleaching in extremes of heat – could be devastating.

“Plastic debris acts like a marine motor home for microbes,” said Joleah Lamb, a researcher at Cornell University in the US. She began gathering data while at James Cook University in Australia.

“Plastics make ideal vessels for colonising microscopic organisms that could trigger disease if they come into contact with corals.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions”

“Plastic items – commonly made of polypropylene, such as bottle caps and toothbrushes – have been shown to become heavily inhabited by bacteria. This is associated with the globally devastating group of coral diseases known as white syndromes.”

She and colleagues from the US, Canada, Australia, Myanmar, Thailand and Indonesia report in the journal Science that between 2011 and 2014 they surveyed 124,000 reef-building corals from 159 reefs in the Asia-Pacific region.

One third of the reefs surveyed were polluted with plastic waste, the highest in Indonesian waters, the lowest off the Australian coast.

They calculate that, right now, the number of plastic bags, cups, bottles, toothbrushes and bits of packaging snagged on the reefs in the region could be 11.1 billion. By 2025, there could be 15.7 bn plastic objects stuck on the same reefs.

No return

And, they report, the presence of plastic was associated with a 20-fold increase in risk of disease, and in particular infections know to marine biologists as skeletal eroding band disease, white syndrome and black band disease.

The items snagged on the corals deprived them of sunlight and oxygen, and weakened the coral to the point at which invasive pathogens could gain a hold.

“What’s troubling about coral disease is that once the coral tissue loss occurs, it’s not coming back,” Dr Lamb said. “It’s like getting gangrene on your foot and there is nothing you can do to stop it from affecting your whole body.”

The Asia-Pacific region is home to more than 55% of the world’s coral reefs. Complex reef structures – reefs with branching corals, for instance – were eight times more likely to trap floating plastic waste.

An estimated 12 billion metric tons of indestructible plastic waste is in the world’s landfills. Somewhere between 4.8 million and 12.7 million metric tons of plastic waste gets into the oceans in a single year.

Rich resource

Coral reefs are among the richest habitats on the planet: a diseased or dying reef can no longer provide food and shelter for a vast range of sea creatures.

Pollution and disease also put at risk much of the estimated $375bn value that reefs offer to 275 million people as sources of fisheries, tourism and coastal protection.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions,” said Drew Harvell, professor of ecology and evolutionary biology at Cornell, and one of the authors.

“While we can’t stop the huge impact of global warming on coral health in the short term, this new work should drive policy toward reducing plastic pollution.” – Climate News Network

Plastic flotsam provides a liferaft for deadly bacteria – and a way of colonising coral reefs with killer infections.

LONDON, 29 January, 2018 – Scientists have established yet another hazard from the millions of tons of plastic waste that tip into the sea: it delivers microbial infection to the world’s coral reefs.

When plastic pollutants snag on coral reefs, the likelihood of disease rises from 4% to 89%, they calculate. That is an increase in risk of more than twentyfold.

And the impact on the world’s reefs – already under increasing hazard from ocean acidification and from bleaching in extremes of heat – could be devastating.

“Plastic debris acts like a marine motor home for microbes,” said Joleah Lamb, a researcher at Cornell University in the US. She began gathering data while at James Cook University in Australia.

“Plastics make ideal vessels for colonising microscopic organisms that could trigger disease if they come into contact with corals.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions”

“Plastic items – commonly made of polypropylene, such as bottle caps and toothbrushes – have been shown to become heavily inhabited by bacteria. This is associated with the globally devastating group of coral diseases known as white syndromes.”

She and colleagues from the US, Canada, Australia, Myanmar, Thailand and Indonesia report in the journal Science that between 2011 and 2014 they surveyed 124,000 reef-building corals from 159 reefs in the Asia-Pacific region.

One third of the reefs surveyed were polluted with plastic waste, the highest in Indonesian waters, the lowest off the Australian coast.

They calculate that, right now, the number of plastic bags, cups, bottles, toothbrushes and bits of packaging snagged on the reefs in the region could be 11.1 billion. By 2025, there could be 15.7 bn plastic objects stuck on the same reefs.

No return

And, they report, the presence of plastic was associated with a 20-fold increase in risk of disease, and in particular infections know to marine biologists as skeletal eroding band disease, white syndrome and black band disease.

The items snagged on the corals deprived them of sunlight and oxygen, and weakened the coral to the point at which invasive pathogens could gain a hold.

“What’s troubling about coral disease is that once the coral tissue loss occurs, it’s not coming back,” Dr Lamb said. “It’s like getting gangrene on your foot and there is nothing you can do to stop it from affecting your whole body.”

The Asia-Pacific region is home to more than 55% of the world’s coral reefs. Complex reef structures – reefs with branching corals, for instance – were eight times more likely to trap floating plastic waste.

An estimated 12 billion metric tons of indestructible plastic waste is in the world’s landfills. Somewhere between 4.8 million and 12.7 million metric tons of plastic waste gets into the oceans in a single year.

Rich resource

Coral reefs are among the richest habitats on the planet: a diseased or dying reef can no longer provide food and shelter for a vast range of sea creatures.

Pollution and disease also put at risk much of the estimated $375bn value that reefs offer to 275 million people as sources of fisheries, tourism and coastal protection.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions,” said Drew Harvell, professor of ecology and evolutionary biology at Cornell, and one of the authors.

“While we can’t stop the huge impact of global warming on coral health in the short term, this new work should drive policy toward reducing plastic pollution.” – Climate News Network

Aquatic life is at risk as carbon levels rise

Marine and freshwater fish could one day be in trouble as ever-rising levels of carbon dioxide affect aquatic life.

LONDON, 18 January, 2018 – New studies warn that global warming is not good news for aquatic life, putting at risk the creatures both of the seas and of inland waterways.

Experiments in Australia confirm that increased temperatures driven by ever-rising atmospheric levels of the greenhouse gas carbon dioxide reduce the flow of energy up the marine food web, which would be bad news for the ocean’s top predators – and some prized fish catches.

Another study finds that ever-greater levels of dissolved carbon dioxide in rivers and lakes could disrupt the dietary supply for creatures higher in the food chain.

Scientists have been warning for years that global warming and ever-increasing levels of acidification could harm ocean productivity. Researchers from the University of Adelaide report in the Public Library of Science journal PLOS Biology that they put the proposition directly to the test.

“Healthy food webs are important for the maintenance of species diversity and provide a source of income and food for millions of people worldwide”

They built 12 huge laboratory aquaria with water temperatures and acidity levels that matched predictions of climate change, and then introduced a range of sea creatures: algae, shrimp, sponges, snails, fishes and so on.

They found that the plants flourished, largely in the form of cyanobacteria, or blue-green algae. “This increased primary productivity does not support food webs, however, because these cyanobacteria are largely unpalatable, and they are not consumed by herbivores,” said Hadayet Ullah, who led the study.

“Healthy food webs are important for the maintenance of species diversity and provide a source of income and food for millions of people worldwide. Therefore, it is important to understand how climate change is altering marine food webs in the near future.”

Alarm, too, about the impact on freshwater species is not new. German biologists had access to data collected every month at four river dams from 1981 to 2015. They report in the journal Current Biology that acidification levels in the reservoirs had steadily increased in that time.

Fleas vulnerable

So they tested the response of species of daphnia, the water flea – and a source of food for other freshwater creatures – to changing water chemistry. The higher the acidity, the weaker the response of the water fleas to the scent of nearby predators.

“Many freshwater organisms rely on their sense of smell. If that sense is compromised in other species due to rising CO2 levels this development might have far-reaching consequences for the entire ecosystem,” said Linda Weiss of the Ruhr University of Bochum, who led the study.

“Follow-up studies must now be carried out, in order to determine if the acidification of freshwater systems is a global phenomenon and in what way other species react to rising CO2 levels.” – Climate News Network

Marine and freshwater fish could one day be in trouble as ever-rising levels of carbon dioxide affect aquatic life.

LONDON, 18 January, 2018 – New studies warn that global warming is not good news for aquatic life, putting at risk the creatures both of the seas and of inland waterways.

Experiments in Australia confirm that increased temperatures driven by ever-rising atmospheric levels of the greenhouse gas carbon dioxide reduce the flow of energy up the marine food web, which would be bad news for the ocean’s top predators – and some prized fish catches.

Another study finds that ever-greater levels of dissolved carbon dioxide in rivers and lakes could disrupt the dietary supply for creatures higher in the food chain.

Scientists have been warning for years that global warming and ever-increasing levels of acidification could harm ocean productivity. Researchers from the University of Adelaide report in the Public Library of Science journal PLOS Biology that they put the proposition directly to the test.

“Healthy food webs are important for the maintenance of species diversity and provide a source of income and food for millions of people worldwide”

They built 12 huge laboratory aquaria with water temperatures and acidity levels that matched predictions of climate change, and then introduced a range of sea creatures: algae, shrimp, sponges, snails, fishes and so on.

They found that the plants flourished, largely in the form of cyanobacteria, or blue-green algae. “This increased primary productivity does not support food webs, however, because these cyanobacteria are largely unpalatable, and they are not consumed by herbivores,” said Hadayet Ullah, who led the study.

“Healthy food webs are important for the maintenance of species diversity and provide a source of income and food for millions of people worldwide. Therefore, it is important to understand how climate change is altering marine food webs in the near future.”

Alarm, too, about the impact on freshwater species is not new. German biologists had access to data collected every month at four river dams from 1981 to 2015. They report in the journal Current Biology that acidification levels in the reservoirs had steadily increased in that time.

Fleas vulnerable

So they tested the response of species of daphnia, the water flea – and a source of food for other freshwater creatures – to changing water chemistry. The higher the acidity, the weaker the response of the water fleas to the scent of nearby predators.

“Many freshwater organisms rely on their sense of smell. If that sense is compromised in other species due to rising CO2 levels this development might have far-reaching consequences for the entire ecosystem,” said Linda Weiss of the Ruhr University of Bochum, who led the study.

“Follow-up studies must now be carried out, in order to determine if the acidification of freshwater systems is a global phenomenon and in what way other species react to rising CO2 levels.” – Climate News Network

Bleaching hits coral reefs faster

Coral reefs have always lived near the edge. Now, thanks to global warming, life there is five times more precarious.

LONDON, 16 January, 2018 – Forty years ago, the world’s coral reefs faced a known risk: every 25 or 30 years, ocean temperatures would rise to intolerable levels.

Corals would minimise the risk of death by everting the algae with which they lived in symbiotic partnership: that is, the reef animals would avoid death by getting rid of the algae, deliberately weakening themselves.

This response is known as bleaching, and it can have a catastrophic effect on other life on the reef. In the Pacific such episodes were sometimes linked to cycles of ocean warming known as an El Niño event.

By 2018 the odds had altered. Coral reefs now face this hazard every six years. That is, in four decades of global warming and climate change, the risks have multiplied fivefold.

Bleaching breaks out

“Before the 1980s, mass bleaching of corals was unheard of, even during strong El Niño conditions, but now repeated bouts of regional-scale bleaching and mass mortality of corals has become the new normal around the world as temperatures continue to rise,” said Terry Hughes, who directs Australia’s Centre of Excellence for Coral Reef Studies at James Cook University.

He and colleagues report in the journal Science that they analysed data from bleaching events at 100 locations around the planet between 1980 and 2016. Bleaching events are a fact of life for corals: these little creatures tend to live best in temperatures near the upper limit of their tolerance levels, and respond to extreme events by rejecting the algae that normally provide the nutrients they need.

But as global air temperatures have increased, in response to profligate burning of fossil fuels that increase greenhouse gas levels in the atmosphere, so have sea temperatures. And Professor Hughes and his team report that in the last two years more than a third of all bleaching events have been “severe,” extending over hundreds of kilometres.

When they measured the growth of risk over the decades, they found that the bleaching hazard had increased by 4% per year since 1980.

“Repeated bouts of regional-scale bleaching and mass mortality of corals has become the new normal around the world”

The finding should be no surprise. In 2015, during a severe El Niño event, scientists began to record cases of coral death. In 2016, they observed that 93% of Australia’s Great Barrier reef had been affected. In 2017 they found that reefs in the western Pacific and off the Indian Ocean had been damaged beyond repair, and a separate set of calculations has warned that by 2100, up to 99% of the world’s coral colonies could be at risk of bleaching every year.

Reefs can recover, but this recovery can take as long as a decade. Coral reefs are among the planet’s richest habitats, and the death of a reef puts many ocean species at risk: it also damages local commercial fish catches and local tourist industries.

“Reefs have entered a distinctive human-dominated era – the Anthropocene,” said Mark Eakin of the US National Oceanic and Atmospheric Administration, a co-author. “The climate has warmed rapidly in the past 50 years, first making El Niños dangerous for corals, and now we’re seeing the emergence of bleaching in every hot summer.”

And Professor Hughes said: “We hope our stark results will help spur on the stronger action needed to reduce greenhouse gases in Australia, the United States and elsewhere.” – Climate News Network

Coral reefs have always lived near the edge. Now, thanks to global warming, life there is five times more precarious.

LONDON, 16 January, 2018 – Forty years ago, the world’s coral reefs faced a known risk: every 25 or 30 years, ocean temperatures would rise to intolerable levels.

Corals would minimise the risk of death by everting the algae with which they lived in symbiotic partnership: that is, the reef animals would avoid death by getting rid of the algae, deliberately weakening themselves.

This response is known as bleaching, and it can have a catastrophic effect on other life on the reef. In the Pacific such episodes were sometimes linked to cycles of ocean warming known as an El Niño event.

By 2018 the odds had altered. Coral reefs now face this hazard every six years. That is, in four decades of global warming and climate change, the risks have multiplied fivefold.

Bleaching breaks out

“Before the 1980s, mass bleaching of corals was unheard of, even during strong El Niño conditions, but now repeated bouts of regional-scale bleaching and mass mortality of corals has become the new normal around the world as temperatures continue to rise,” said Terry Hughes, who directs Australia’s Centre of Excellence for Coral Reef Studies at James Cook University.

He and colleagues report in the journal Science that they analysed data from bleaching events at 100 locations around the planet between 1980 and 2016. Bleaching events are a fact of life for corals: these little creatures tend to live best in temperatures near the upper limit of their tolerance levels, and respond to extreme events by rejecting the algae that normally provide the nutrients they need.

But as global air temperatures have increased, in response to profligate burning of fossil fuels that increase greenhouse gas levels in the atmosphere, so have sea temperatures. And Professor Hughes and his team report that in the last two years more than a third of all bleaching events have been “severe,” extending over hundreds of kilometres.

When they measured the growth of risk over the decades, they found that the bleaching hazard had increased by 4% per year since 1980.

“Repeated bouts of regional-scale bleaching and mass mortality of corals has become the new normal around the world”

The finding should be no surprise. In 2015, during a severe El Niño event, scientists began to record cases of coral death. In 2016, they observed that 93% of Australia’s Great Barrier reef had been affected. In 2017 they found that reefs in the western Pacific and off the Indian Ocean had been damaged beyond repair, and a separate set of calculations has warned that by 2100, up to 99% of the world’s coral colonies could be at risk of bleaching every year.

Reefs can recover, but this recovery can take as long as a decade. Coral reefs are among the planet’s richest habitats, and the death of a reef puts many ocean species at risk: it also damages local commercial fish catches and local tourist industries.

“Reefs have entered a distinctive human-dominated era – the Anthropocene,” said Mark Eakin of the US National Oceanic and Atmospheric Administration, a co-author. “The climate has warmed rapidly in the past 50 years, first making El Niños dangerous for corals, and now we’re seeing the emergence of bleaching in every hot summer.”

And Professor Hughes said: “We hope our stark results will help spur on the stronger action needed to reduce greenhouse gases in Australia, the United States and elsewhere.” – Climate News Network

Rising vineyard heat hits grape pickers

As the heat rises, output flags. European scientists have measured every second of a working day as the vineyard heat hits grape pickers.

LONDON, 22 July, 2017  White wine should be served chilled. Red wine should be served at room temperature. But inevitably the vineyard heat hits grape pickers who would count themselves not just lucky but more productive if they could pick on a mild day.

And as global temperatures rise, grape harvests could be affected simply because manual worker efficiency goes down as the mercury goes up, according to a new study.

Researchers from Greece, Cyprus, Denmark and Canada report that higher temperatures for grape pickers correlated with a significant labour loss of up to 27%: the physical cost of labour in temperatures of 36°C – which can happen in the vineyards of Cyprus – told on the metabolic and cardiovascular systems of the grape pickers, and resulted in reduced output, according to a study in the journal Temperature

Wine is big business: it now accounts for one 500th of the global GDP and is a significant component in the economies of France, Germany and southern Europe, as well as California, Chile, Argentina, Australia and New Zealand.

Researchers have already begun to measure the impact of global warming and climate change as a consequence of the profligate combustion of fossil fuels worldwide. Higher summer temperatures and earlier springs have shifted the vintages earlier in the year as European temperatures start to rise.  

Unequal impacts

Such changes have paid off for some, as the conditions for viticulture shift northwards, but they have created problems in the more southerly zones, even casting doubts on the future of that natural stopper cork, from the bark of the cork oak.

And although researchers have warned about the costs of extremes of heat to economies around the world, and to Australia in particular, there has been little direct study of the impact of temperature rise on European workers in a particular field of agriculture.

Much agriculture is now machine-driven, but for more than 5,000 years grapes have been picked by hand: in Cyprus pickers must do this in August temperatures of 36°C, which in Germany would be considered a heatwave. Under such conditions, worker health and efficiency becomes a concern.

Grapes, too, respond to climate conditions – that is why some vintages are more valued than others – so the European scientists had to devise a way of measuring the human costs of labour in higher temperatures rather than overall economic losses.

“The studied grape-picking workers experienced increased workplace heat, leading to a significant labour loss”

They monitored workers near Paphos in Cyprus on four separate days in 2016, spread through a grape harvest that began in August and ended in October. They selected seven healthy workers accustomed to working in the heat, they made physical measurements of each worker, they monitored heat, humidity and breeze, and they used video studies to analyse time and motion not just by the hour, but by the second.

To avoid bias in the outcome, they initially told the selected workers it would be for a video about the making of wine, and then later told them the real reason and got their consent to the experiment. Altogether, they recorded the picking of 9,600 kg of grapes.

And they found that, on the hotter days of the experiment, the time spent not working during each eight-hour shift was higher. On the hottest days, irregular work breaks reached 15.3% of the working day; in the cooler autumn this fell to 10%. Altogether there was up to 2.1% increase in work-break time per hour with each rise of 1°C in the temperature.

The researchers write that their measurements proved more accurate than vineyard managers’ estimates of efficiency, that time and motion analysis delivers a reliable way of measuring output, and more emphatically that heat affects the ability to work.

“The studied grape-picking workers experienced increased workplace heat, leading to a significant labour loss,” they write. – Climate News Network

As the heat rises, output flags. European scientists have measured every second of a working day as the vineyard heat hits grape pickers.

LONDON, 22 July, 2017  White wine should be served chilled. Red wine should be served at room temperature. But inevitably the vineyard heat hits grape pickers who would count themselves not just lucky but more productive if they could pick on a mild day.

And as global temperatures rise, grape harvests could be affected simply because manual worker efficiency goes down as the mercury goes up, according to a new study.

Researchers from Greece, Cyprus, Denmark and Canada report that higher temperatures for grape pickers correlated with a significant labour loss of up to 27%: the physical cost of labour in temperatures of 36°C – which can happen in the vineyards of Cyprus – told on the metabolic and cardiovascular systems of the grape pickers, and resulted in reduced output, according to a study in the journal Temperature

Wine is big business: it now accounts for one 500th of the global GDP and is a significant component in the economies of France, Germany and southern Europe, as well as California, Chile, Argentina, Australia and New Zealand.

Researchers have already begun to measure the impact of global warming and climate change as a consequence of the profligate combustion of fossil fuels worldwide. Higher summer temperatures and earlier springs have shifted the vintages earlier in the year as European temperatures start to rise.  

Unequal impacts

Such changes have paid off for some, as the conditions for viticulture shift northwards, but they have created problems in the more southerly zones, even casting doubts on the future of that natural stopper cork, from the bark of the cork oak.

And although researchers have warned about the costs of extremes of heat to economies around the world, and to Australia in particular, there has been little direct study of the impact of temperature rise on European workers in a particular field of agriculture.

Much agriculture is now machine-driven, but for more than 5,000 years grapes have been picked by hand: in Cyprus pickers must do this in August temperatures of 36°C, which in Germany would be considered a heatwave. Under such conditions, worker health and efficiency becomes a concern.

Grapes, too, respond to climate conditions – that is why some vintages are more valued than others – so the European scientists had to devise a way of measuring the human costs of labour in higher temperatures rather than overall economic losses.

“The studied grape-picking workers experienced increased workplace heat, leading to a significant labour loss”

They monitored workers near Paphos in Cyprus on four separate days in 2016, spread through a grape harvest that began in August and ended in October. They selected seven healthy workers accustomed to working in the heat, they made physical measurements of each worker, they monitored heat, humidity and breeze, and they used video studies to analyse time and motion not just by the hour, but by the second.

To avoid bias in the outcome, they initially told the selected workers it would be for a video about the making of wine, and then later told them the real reason and got their consent to the experiment. Altogether, they recorded the picking of 9,600 kg of grapes.

And they found that, on the hotter days of the experiment, the time spent not working during each eight-hour shift was higher. On the hottest days, irregular work breaks reached 15.3% of the working day; in the cooler autumn this fell to 10%. Altogether there was up to 2.1% increase in work-break time per hour with each rise of 1°C in the temperature.

The researchers write that their measurements proved more accurate than vineyard managers’ estimates of efficiency, that time and motion analysis delivers a reliable way of measuring output, and more emphatically that heat affects the ability to work.

“The studied grape-picking workers experienced increased workplace heat, leading to a significant labour loss,” they write. – Climate News Network

Hungry aardvarks show wider climate impact

When the food source fails, the hunter too is at risk. Africa’s hungry aardvarks offer a lesson in climate hazards.

LONDON, 20 July, 2017 – Hungry aardvarks in sub-Saharan Africa may be putting other species at risk of the effects of a warming climate, researchers believe.

The celebrated aardvark – a nocturnal burrowing anteater beloved of word-gamers and dictionary compilers – could not only be threatened itself by climate change, they say: its fate could also be bad news for the creatures which depend on it..

Although Orycteropus afer or earth-pig is not thought to be at serious risk of extinction, a detailed study of the anteaters in the Kalahari region of southern Africa has produced alarming outcomes.

Biologists report in the Royal Society journal Biology Letters that they planted “biologgers” to record their movement patterns in six adult animals that lived in the semi-arid Kalahari.

Wider jeopardy

The summer was particularly hot and dry, and at the end of it five of the recorded aardvarks were dead. So were 11 other aardvarks in the same patch of territory under study.

“Our results do not bode well for the future of aardvarks facing climate change,” they say. Since aardvarks play a key role in engineering African ecosystems, other species may suffer.

The aardvark is known worldwide, if only because it is always on the first page of any dictionary. But most people have never seen one, and know only that these creatures are committed myrmecophages: that is, they live on a diet of ants and termites.

They burrow to stay clear of the heat of the day, and their burrows then become homes or shelters for other species. According to one study at least 27 vertebrate animals – 21 mammals, two birds, three reptiles and an amphibian – have been observed in old aardvark diggings.

Investigating stress

The research tells a story of the kind of stress that might be expected with climate change. Under anaesthetic, the South African scientists implanted sensors that could record body temperature and movement, and trackers that could follow the animals as they searched for food. Then they let them back into the wild. It was 2013.

The thermometer rose, summer rains came late, overall rainfall was low, and a severe drought followed. By the end of the summer, five were dead: the researchers recovered most of their instruments and read the data.

They found that, initially, aardvark body temperatures were consistent at 35.4°C to 37.2°C.  As the summer wore on, body temperature declined, reaching, they said “as low as 25°C before death, likely due to starvation.”

Researchers have consistently warned that global warming and consequent climate change offers a threat to the creatures of the wild.

“The extirpation of aardvarks that function as physical ecosystem engineers may disrupt ecosystem stability and result in an undesirable ecological cascade”

Although habitat loss, overhunting and pollution offer the biggest threat, other studies have found that the pattern of warming has begun to disrupt whole ecosystems and that even where species are likely to survive, the number of “local extinctions” – regions that were once rich in particular birds or butterflies but record them no more – is on the increase.

The aardvark study is a confirmation of how this can happen: if one hot dry summer means a loss of prey, then the predator population crashes. If heat and drought become part of regional climate, then hunters migrate, or die.

The aardvark is what ecologists call a “keystone species”: that is, other animals depend on it in some way. “The burrows excavated by aardvarks provide thermal refugia for at least 27 vertebrate species. With climate change, these refugia will become increasingly important for those species to buffer climatic extremes,” the researchers conclude.

“The extirpation of aardvarks that function as physical ecosystem engineers, therefore, may disrupt ecosystem stability and result in an undesirable ecological cascade, as seen with digging mammals in Australia. We may face a similar scenario in African ecosystems.” Climate News Network

When the food source fails, the hunter too is at risk. Africa’s hungry aardvarks offer a lesson in climate hazards.

LONDON, 20 July, 2017 – Hungry aardvarks in sub-Saharan Africa may be putting other species at risk of the effects of a warming climate, researchers believe.

The celebrated aardvark – a nocturnal burrowing anteater beloved of word-gamers and dictionary compilers – could not only be threatened itself by climate change, they say: its fate could also be bad news for the creatures which depend on it..

Although Orycteropus afer or earth-pig is not thought to be at serious risk of extinction, a detailed study of the anteaters in the Kalahari region of southern Africa has produced alarming outcomes.

Biologists report in the Royal Society journal Biology Letters that they planted “biologgers” to record their movement patterns in six adult animals that lived in the semi-arid Kalahari.

Wider jeopardy

The summer was particularly hot and dry, and at the end of it five of the recorded aardvarks were dead. So were 11 other aardvarks in the same patch of territory under study.

“Our results do not bode well for the future of aardvarks facing climate change,” they say. Since aardvarks play a key role in engineering African ecosystems, other species may suffer.

The aardvark is known worldwide, if only because it is always on the first page of any dictionary. But most people have never seen one, and know only that these creatures are committed myrmecophages: that is, they live on a diet of ants and termites.

They burrow to stay clear of the heat of the day, and their burrows then become homes or shelters for other species. According to one study at least 27 vertebrate animals – 21 mammals, two birds, three reptiles and an amphibian – have been observed in old aardvark diggings.

Investigating stress

The research tells a story of the kind of stress that might be expected with climate change. Under anaesthetic, the South African scientists implanted sensors that could record body temperature and movement, and trackers that could follow the animals as they searched for food. Then they let them back into the wild. It was 2013.

The thermometer rose, summer rains came late, overall rainfall was low, and a severe drought followed. By the end of the summer, five were dead: the researchers recovered most of their instruments and read the data.

They found that, initially, aardvark body temperatures were consistent at 35.4°C to 37.2°C.  As the summer wore on, body temperature declined, reaching, they said “as low as 25°C before death, likely due to starvation.”

Researchers have consistently warned that global warming and consequent climate change offers a threat to the creatures of the wild.

“The extirpation of aardvarks that function as physical ecosystem engineers may disrupt ecosystem stability and result in an undesirable ecological cascade”

Although habitat loss, overhunting and pollution offer the biggest threat, other studies have found that the pattern of warming has begun to disrupt whole ecosystems and that even where species are likely to survive, the number of “local extinctions” – regions that were once rich in particular birds or butterflies but record them no more – is on the increase.

The aardvark study is a confirmation of how this can happen: if one hot dry summer means a loss of prey, then the predator population crashes. If heat and drought become part of regional climate, then hunters migrate, or die.

The aardvark is what ecologists call a “keystone species”: that is, other animals depend on it in some way. “The burrows excavated by aardvarks provide thermal refugia for at least 27 vertebrate species. With climate change, these refugia will become increasingly important for those species to buffer climatic extremes,” the researchers conclude.

“The extirpation of aardvarks that function as physical ecosystem engineers, therefore, may disrupt ecosystem stability and result in an undesirable ecological cascade, as seen with digging mammals in Australia. We may face a similar scenario in African ecosystems.” Climate News Network

Nuclear war would set off climate catastrophe

Even a small nuclear war could end global warming. But it would certainly precipitate catastrophic climate change.

LONDON, 18 July, 2017 – Four US scientists have just introduced one more good reason not to launch a nuclear war. It would not simply guarantee the mutual destruction of the participants. It would also precipitate catastrophic climate change.

And, they argue in the journal Environment Magazine, even a single nuclear missile strike could darken the skies, chill the atmosphere, stop rainfall, ruin harvests and cost a billion lives.

Observers with memories that stretch back to the Cold War and the arms race between the US and Nato powers on the one hand and the USSR on the other will know something of this already.

In 1983 the astronomer Carl Sagan and colleagues introduced the idea of global annihilation, or at least the end of human civilisation, in a “nuclear winter” as a consequence of a nuclear weapons exchange.

Years later, as the Soviet Union collapsed and the Russian Federation was born, the same scientists did their calculations again, and reduced the threat to a kind of “nuclear autumn”.

Nuclear club

Eight nations now possess a nuclear arsenal; the US, Russia and China all have nuclear weapons big enough to precipitate a nuclear calamity, and a ninth, North Korea, now claims to have nuclear capability.

This prompted researchers and political scientists from the University of Nebraska Lincoln to revisit the question, based on a theoretical study of the effect of one hundred 15-kiloton warheads, with the explosive power of 150,000 tons of TNT.

Once exploded, such a strike would incinerate 1,300 square kilometres of a city and its surrounds. This would be quite enough to push five million metric tons of black carbon smoke particles into the stratosphere.

This would be enough to screen solar radiation, reduce the agricultural crop season by between 10 and 40 days a year for at least five years, and lower global temperatures to a point lower than normal for at least 25 years.

In the very short term, this cold snap would be colder than anything for the last 1,000 years. Rainfall would decrease by as much as 20% to 80% in the Asian monsoon region.

“Even a conflict that doesn’t involve the United States can impact us and people around the world”

The American southwest and western Australia could become 20% to 60% drier. South America and southern Africa, too, would see less rain. This global “nuclear drought” and the resulting famines “could kill up to a billion people from starvation.”

The most immediate victims would be those in countries that are already poor or food-insecure. And, the scientists warn, should a warhead fall upon a nuclear power facility “the spread of toxic radionuclides and their long-term effects would be greatly magnified.”

The drop in precipitation would, they warn, also increase conflict in developing regions,  “although global temperature reduction may reduce social violence in the United States and other developed countries.”

“We’re losing our memory of the Cold War and we’re losing our memory of how important it is to get this right,” said Tyler White, a political scientist concerned with international security and nuclear policy, and one of the authors. 

“Even a conflict that doesn’t involve the United States can impact us and people around the world.” – Climate News Network

Even a small nuclear war could end global warming. But it would certainly precipitate catastrophic climate change.

LONDON, 18 July, 2017 – Four US scientists have just introduced one more good reason not to launch a nuclear war. It would not simply guarantee the mutual destruction of the participants. It would also precipitate catastrophic climate change.

And, they argue in the journal Environment Magazine, even a single nuclear missile strike could darken the skies, chill the atmosphere, stop rainfall, ruin harvests and cost a billion lives.

Observers with memories that stretch back to the Cold War and the arms race between the US and Nato powers on the one hand and the USSR on the other will know something of this already.

In 1983 the astronomer Carl Sagan and colleagues introduced the idea of global annihilation, or at least the end of human civilisation, in a “nuclear winter” as a consequence of a nuclear weapons exchange.

Years later, as the Soviet Union collapsed and the Russian Federation was born, the same scientists did their calculations again, and reduced the threat to a kind of “nuclear autumn”.

Nuclear club

Eight nations now possess a nuclear arsenal; the US, Russia and China all have nuclear weapons big enough to precipitate a nuclear calamity, and a ninth, North Korea, now claims to have nuclear capability.

This prompted researchers and political scientists from the University of Nebraska Lincoln to revisit the question, based on a theoretical study of the effect of one hundred 15-kiloton warheads, with the explosive power of 150,000 tons of TNT.

Once exploded, such a strike would incinerate 1,300 square kilometres of a city and its surrounds. This would be quite enough to push five million metric tons of black carbon smoke particles into the stratosphere.

This would be enough to screen solar radiation, reduce the agricultural crop season by between 10 and 40 days a year for at least five years, and lower global temperatures to a point lower than normal for at least 25 years.

In the very short term, this cold snap would be colder than anything for the last 1,000 years. Rainfall would decrease by as much as 20% to 80% in the Asian monsoon region.

“Even a conflict that doesn’t involve the United States can impact us and people around the world”

The American southwest and western Australia could become 20% to 60% drier. South America and southern Africa, too, would see less rain. This global “nuclear drought” and the resulting famines “could kill up to a billion people from starvation.”

The most immediate victims would be those in countries that are already poor or food-insecure. And, the scientists warn, should a warhead fall upon a nuclear power facility “the spread of toxic radionuclides and their long-term effects would be greatly magnified.”

The drop in precipitation would, they warn, also increase conflict in developing regions,  “although global temperature reduction may reduce social violence in the United States and other developed countries.”

“We’re losing our memory of the Cold War and we’re losing our memory of how important it is to get this right,” said Tyler White, a political scientist concerned with international security and nuclear policy, and one of the authors. 

“Even a conflict that doesn’t involve the United States can impact us and people around the world.” – Climate News Network

Best ways to cut climate change are overlooked

Governments and schools are failing to help people to recognise the best ways to cut climate change, researchers say.

LONDON, 13 July, 2017 – Teachers and policymakers are missing a golden opportunity to show people the best ways to cut climate change and reduce their carbon footprint, a study says.

It identifies four ways of behaving that it says will have the most substantial effect in decreasing someone’s climate impact: eating a plant-based diet, avoiding air travel, living without reliance on a car, and having smaller families.

The researchers, from Lund University in Sweden, analysed 39 peer-reviewed papers, carbon calculators and government reports to calculate the potential of a range of individual lifestyle choices to reduce greenhouse gas emissions. They say their comprehensive analysis identifies what people can do to have the greatest impact.

Writing in the journal Environmental Research Lettersthe authors say their study found the incremental changes advocated by governments may represent a missed opportunity to reduce greenhouse gas emissions beneath the levels needed to prevent 2°C of climate warming, the goal set by the 2015 Paris Agreement.

Better choices 

The lead author of the Swedish study, Seth Wynes, said: “There are so many factors that affect the climate impact of personal choices, but bringing all these studies side-by-side gives us confidence we’ve identified actions that make a big difference.

“Those of us who want to step forward on climate need to know how our actions can have the greatest possible impact. This research is about helping people make more informed choices.

“For example, living car-free saves about 2.4 tonnes of CO2 equivalent per year, while eating a plant-based diet saves 0.8 tonnes of CO2 equivalent a year.

“These actions, therefore, have much greater potential to reduce emissions than commonly promoted strategies like comprehensive recycling (which is four times less effective than a plant-based diet) or changing household lightbulbs (eight times less effective).”

Less potential

The researchers also found that neither Canadian school textbooks nor government resources from the EU, US, Canada and Australia highlight these actions, focusing instead  on incremental changes with much smaller potential to reduce emissions.

Study co-author Kimberly Nicholas said: “We recognise these are deeply personal choices. But we can’t ignore the climate effect our lifestyle actually has. Personally, I’ve found it really positive to make many of these changes. It’s especially important for young people establishing lifelong patterns to be aware which choices have the biggest impact.”

The four behavioural changes on which the study concentrates have all been urged to different degrees, from the virtues of eating no (or at least less) meat to avoiding flying and reducing car pollution. There have also been warnings about the impact of that sensitive issue, human numbers.

Current averages 

All the choices were compared on a life cycle basis for one individual making the decision under current average conditions in developed countries. This means, for example, that the emissions saved by switching from the prevailing Northern omnivorous diet to a plant-based one includes emissions from fertilisers, methane production by livestock, and the transport of food to shops and markets. 

The calculation for flights is based on the emissions for one person flying on a return flight (for instance New York to London) under average conditions, while living car-free estimates not only the emissions saved per person (based on average vehicle miles travelled and vehicle occupancy) but also those from vehicle production and maintenance, and from the burning of fuel.

The calculation on family size measures the cumulative impact of current and future descendants, and current levels for all emissions produced over the lifespan of descendants, divided by the life expectancy of the parent.  

Buying green energy, often suggested as an effective way to cut a person’s carbon footprint, was sometimes but not always treated by the researchers as a high-impact action.

“Though some high-impact actions may be politically unpopular, from an emissions reduction perspective this does not justify a focus on moderate or low-impact actions at the expense of high-impact actions”

They say the sorts of behaviour that are most effective at reducing people’s personal emissions can also be seen as desirable choices which promote a slower and healthier lifestyle.

They also confront the distinct possibility that some readers will not like their suggestions: “Though some high-impact actions may be politically unpopular, from an emissions reduction perspective this does not justify a focus on moderate or low-impact actions at the expense of high-impact actions.

“As a specific example, one textbook says ‘making a difference doesn’t have to be difficult’ and provides the example of switching from plastic bags to reusable shopping bags in order to save 5kg of CO2 per year. This is less than 1% as effective as a year without eating meat. Examples like this represent missed opportunities to encourage serious engagement on climate change.

“Focusing on high-impact actions (through providing accurate guidance and information, especially to ‘catalytic’ individuals such as adolescents) could be an important dimension of scaling bottom-up action to the transformative decarbonisation implied by the Paris Agreement.” – Climate News Network

Governments and schools are failing to help people to recognise the best ways to cut climate change, researchers say.

LONDON, 13 July, 2017 – Teachers and policymakers are missing a golden opportunity to show people the best ways to cut climate change and reduce their carbon footprint, a study says.

It identifies four ways of behaving that it says will have the most substantial effect in decreasing someone’s climate impact: eating a plant-based diet, avoiding air travel, living without reliance on a car, and having smaller families.

The researchers, from Lund University in Sweden, analysed 39 peer-reviewed papers, carbon calculators and government reports to calculate the potential of a range of individual lifestyle choices to reduce greenhouse gas emissions. They say their comprehensive analysis identifies what people can do to have the greatest impact.

Writing in the journal Environmental Research Lettersthe authors say their study found the incremental changes advocated by governments may represent a missed opportunity to reduce greenhouse gas emissions beneath the levels needed to prevent 2°C of climate warming, the goal set by the 2015 Paris Agreement.

Better choices 

The lead author of the Swedish study, Seth Wynes, said: “There are so many factors that affect the climate impact of personal choices, but bringing all these studies side-by-side gives us confidence we’ve identified actions that make a big difference.

“Those of us who want to step forward on climate need to know how our actions can have the greatest possible impact. This research is about helping people make more informed choices.

“For example, living car-free saves about 2.4 tonnes of CO2 equivalent per year, while eating a plant-based diet saves 0.8 tonnes of CO2 equivalent a year.

“These actions, therefore, have much greater potential to reduce emissions than commonly promoted strategies like comprehensive recycling (which is four times less effective than a plant-based diet) or changing household lightbulbs (eight times less effective).”

Less potential

The researchers also found that neither Canadian school textbooks nor government resources from the EU, US, Canada and Australia highlight these actions, focusing instead  on incremental changes with much smaller potential to reduce emissions.

Study co-author Kimberly Nicholas said: “We recognise these are deeply personal choices. But we can’t ignore the climate effect our lifestyle actually has. Personally, I’ve found it really positive to make many of these changes. It’s especially important for young people establishing lifelong patterns to be aware which choices have the biggest impact.”

The four behavioural changes on which the study concentrates have all been urged to different degrees, from the virtues of eating no (or at least less) meat to avoiding flying and reducing car pollution. There have also been warnings about the impact of that sensitive issue, human numbers.

Current averages 

All the choices were compared on a life cycle basis for one individual making the decision under current average conditions in developed countries. This means, for example, that the emissions saved by switching from the prevailing Northern omnivorous diet to a plant-based one includes emissions from fertilisers, methane production by livestock, and the transport of food to shops and markets. 

The calculation for flights is based on the emissions for one person flying on a return flight (for instance New York to London) under average conditions, while living car-free estimates not only the emissions saved per person (based on average vehicle miles travelled and vehicle occupancy) but also those from vehicle production and maintenance, and from the burning of fuel.

The calculation on family size measures the cumulative impact of current and future descendants, and current levels for all emissions produced over the lifespan of descendants, divided by the life expectancy of the parent.  

Buying green energy, often suggested as an effective way to cut a person’s carbon footprint, was sometimes but not always treated by the researchers as a high-impact action.

“Though some high-impact actions may be politically unpopular, from an emissions reduction perspective this does not justify a focus on moderate or low-impact actions at the expense of high-impact actions”

They say the sorts of behaviour that are most effective at reducing people’s personal emissions can also be seen as desirable choices which promote a slower and healthier lifestyle.

They also confront the distinct possibility that some readers will not like their suggestions: “Though some high-impact actions may be politically unpopular, from an emissions reduction perspective this does not justify a focus on moderate or low-impact actions at the expense of high-impact actions.

“As a specific example, one textbook says ‘making a difference doesn’t have to be difficult’ and provides the example of switching from plastic bags to reusable shopping bags in order to save 5kg of CO2 per year. This is less than 1% as effective as a year without eating meat. Examples like this represent missed opportunities to encourage serious engagement on climate change.

“Focusing on high-impact actions (through providing accurate guidance and information, especially to ‘catalytic’ individuals such as adolescents) could be an important dimension of scaling bottom-up action to the transformative decarbonisation implied by the Paris Agreement.” – Climate News Network

World’s reefs damaged beyond repair

reefs great barrier reef

Australia’s Great Barrier Reef and reefs in the Maldives have been dangerously weakened by coral bleaching caused by global warming and El Niño events.

LONDON, 24 March, 2017 The Great Barrier Reef, one of the wonders of the Pacific Ocean, may never fully recover from the combined effects of global warming and an El Niño year, according to a new study in one of the world’s leading science journals.

And a second study, in a second journal, warns that increased sea surface temperatures have also caused both a major die-off of corals and the collapse of reef growth rates in the Maldives, in the Indian Ocean.

Corals are very sensitive to ocean temperatures, and in unusually hot years and these have recurred naturally and cyclically since long before humans started burning coal, oil and gas, to accelerate the build-up of greenhouse gases in the atmosphere – the corals react to stress by bleaching. That is, they eject the photosynthesising algae that live with them in symbiosis, to the advantage of both creatures.

Hotter oceans

But the world’s oceans are becoming hotter anyway, because of global warming driven by greenhouse gas concentrations in the atmosphere. The seas are becoming ever more acidic as atmospheric carbon dioxide reacts with the water.

And the periodic return of a blister of oceanic heat in the eastern Pacific called El Niño – Spanish for “The Child”, because it becomes most visible around Christmastime – has begun to put the world’s reefs at risk. The El Niño of 2015-16 triggered a massive episode of bleaching throughout the tropics. And, Australian researchers say in Nature, the bleaching continues.

We’re hoping that the next two to three weeks will cool off quickly, and this year’s bleaching won’t be anything like last year. The severity of the 2016 bleaching was off the chart,” says Terry Hughes, of Australia’s Centre of Excellence for Coral Reef Studies, at James Cook University in Queensland.

It was the third major bleaching to affect the Great Barrier Reef, following earlier heatwaves in 1998 and 2002. Now we’re gearing up to study a potential number four.

We have now assessed whether past exposure to bleaching in 1998 and 2002 made reefs any more tolerant in 2016. Sadly, we found no evidence that past bleaching makes the corals any tougher.”

Recovery from similar past disturbances
in the Maldives has taken 10-15 years, but major
bleaching events are predicted to become
far more frequent than this”

Researchers have already warned that, unless there is urgent action to limit global warming by drastically reducing dependence on fossil fuel as an energy source, severe bleaching could damage 99% of the world’s coral reefs.

The reefs are among the richest ecosystems on the planet, and they provide vital coastal protection for human settlements as well as a source of sustainable protein for human economies.

It broke my heart to see so many corals dying on northern reefs on the Great Barrier Reef in 2016,” says Professor Hughes. “With rising temperatures due to global warming, it’s only a matter of time before we see more of these events. A fourth event after only one year is a major blow to the Reef.”

British scientists saw much the same devastation from the same El Niño bleaching around the Maldives in the Indian Ocean, they write in Scientific Reports journal. And the big question now is: how quickly can the Indian Ocean reefs recover?

Growth rate of reefs

Recovery from similar past disturbances in the Maldives has taken 10-15 years, but major bleaching events are predicted to become far more frequent than this. If this is the case it could lead to long-term loss of reef growth and so limit the coastal protection and habitat services these reefs presently provide,” says Chris Perry, professor of physical geography at the University of Exeter, UK.

The most alarming aspect of this coral die-off event is that it has led to a rapid and very large decline in the growth rate of the reefs.

This in turn has major implications not only for the capacity of these reefs to match any increases in sea-level, but because it is also likely to lead to a loss of the surface structure of the reefs that is so critical for supporting fish species diversity and abundance.” Climate News Network

Australia’s Great Barrier Reef and reefs in the Maldives have been dangerously weakened by coral bleaching caused by global warming and El Niño events.

LONDON, 24 March, 2017 The Great Barrier Reef, one of the wonders of the Pacific Ocean, may never fully recover from the combined effects of global warming and an El Niño year, according to a new study in one of the world’s leading science journals.

And a second study, in a second journal, warns that increased sea surface temperatures have also caused both a major die-off of corals and the collapse of reef growth rates in the Maldives, in the Indian Ocean.

Corals are very sensitive to ocean temperatures, and in unusually hot years and these have recurred naturally and cyclically since long before humans started burning coal, oil and gas, to accelerate the build-up of greenhouse gases in the atmosphere – the corals react to stress by bleaching. That is, they eject the photosynthesising algae that live with them in symbiosis, to the advantage of both creatures.

Hotter oceans

But the world’s oceans are becoming hotter anyway, because of global warming driven by greenhouse gas concentrations in the atmosphere. The seas are becoming ever more acidic as atmospheric carbon dioxide reacts with the water.

And the periodic return of a blister of oceanic heat in the eastern Pacific called El Niño – Spanish for “The Child”, because it becomes most visible around Christmastime – has begun to put the world’s reefs at risk. The El Niño of 2015-16 triggered a massive episode of bleaching throughout the tropics. And, Australian researchers say in Nature, the bleaching continues.

We’re hoping that the next two to three weeks will cool off quickly, and this year’s bleaching won’t be anything like last year. The severity of the 2016 bleaching was off the chart,” says Terry Hughes, of Australia’s Centre of Excellence for Coral Reef Studies, at James Cook University in Queensland.

It was the third major bleaching to affect the Great Barrier Reef, following earlier heatwaves in 1998 and 2002. Now we’re gearing up to study a potential number four.

We have now assessed whether past exposure to bleaching in 1998 and 2002 made reefs any more tolerant in 2016. Sadly, we found no evidence that past bleaching makes the corals any tougher.”

Recovery from similar past disturbances
in the Maldives has taken 10-15 years, but major
bleaching events are predicted to become
far more frequent than this”

Researchers have already warned that, unless there is urgent action to limit global warming by drastically reducing dependence on fossil fuel as an energy source, severe bleaching could damage 99% of the world’s coral reefs.

The reefs are among the richest ecosystems on the planet, and they provide vital coastal protection for human settlements as well as a source of sustainable protein for human economies.

It broke my heart to see so many corals dying on northern reefs on the Great Barrier Reef in 2016,” says Professor Hughes. “With rising temperatures due to global warming, it’s only a matter of time before we see more of these events. A fourth event after only one year is a major blow to the Reef.”

British scientists saw much the same devastation from the same El Niño bleaching around the Maldives in the Indian Ocean, they write in Scientific Reports journal. And the big question now is: how quickly can the Indian Ocean reefs recover?

Growth rate of reefs

Recovery from similar past disturbances in the Maldives has taken 10-15 years, but major bleaching events are predicted to become far more frequent than this. If this is the case it could lead to long-term loss of reef growth and so limit the coastal protection and habitat services these reefs presently provide,” says Chris Perry, professor of physical geography at the University of Exeter, UK.

The most alarming aspect of this coral die-off event is that it has led to a rapid and very large decline in the growth rate of the reefs.

This in turn has major implications not only for the capacity of these reefs to match any increases in sea-level, but because it is also likely to lead to a loss of the surface structure of the reefs that is so critical for supporting fish species diversity and abundance.” Climate News Network