Tag Archives: Temperature rise

Unique climate change has no natural cause

The planet is warming faster than ever, worldwide. Scientists know this unique climate change is not caused by nature. But they checked again, to be certain.

LONDON, 19 August, 2019 – European and US scientists have cleared up a point that has been nagging away at climate science for decades: not only is the planet warming faster than at any time in the last 2,000 years, but this unique climate change really does have neither a historic precedent nor a natural cause.

Other historic changes – the so-called Medieval Warm Period and then the “Little Ice Age” that marked the 17th to the 19th centuries – were not global. The only period in which the world’s climate has changed, everywhere and at the same time, is right now.

And other shifts in the past, marked by advancing Alpine glaciers and sustained droughts in Africa, could be pinned down to a flurry of violent volcanic activity.

The present sustained, ubiquitous warming is unique in that it can be coupled directly with the Industrial Revolution, the clearing of the forests, population growth and profligate use of fossil fuels.

The finding is part of a sustained examination of global climate history, based not just on written and pictorial records but also studies of ancient lake sediments, ice cores, tree rings and other proxy evidence assembled by an international partnership called the Past Global Changes Consortium. It is reported in the journal Nature.

“This paper should finally stop climate change deniers claiming that the recent observed coherent global warming is part of a natural climate cycle”

Research like this is a tidying-up operation. Climate scientists, conservationists, glaciologists, marine biologists, geologists and economists all know that climate change is happening, and that it is happening as a consequence of accelerated human activity over the last two centuries.

But from the start, there have always been gnawing questions: hasn’t the climate always changed? If global temperatures rose between 700 AD and 1400 AD, and then fell again, is what is happening now not part of some similar long-term cycle? And until now, that has remained without a confident, categorical answer.

So the latest study surprises nobody. But it matters, because the Nature study clarifies a point of possible confusion. There have been changes in modern human history, but none of them global and synchronous (happening at the same time). They were random fluctuations within the climate system, and even changes in solar activity or volcanic surges could not affect all of the planet at any one time.

“It’s true that during the Little Ice Age it was generally colder across the whole world,” says Raphel Neukom of the University of Bern in Switzerland, and first author, “but not everywhere at the same time. The peak periods of pre-industrial warm and cold periods occurred at different times in different places.”

And his Bern colleague Stefan Brönnimann clears up another point in a related study in the pages of Nature Geoscience.

Volcanic influence

The Little Ice Age began in Europe with no obvious trigger, but it was certainly reinforced and extended by more violent than usual volcanic activity in the tropics between 1808 and 1835. Mt Tambora in what is now Indonesia put so much ash into the stratosphere to screen sunlight and drop temperatures that 1816 became known as the Year without a Summer.

But there were also four other eruptions. Between 1820 and 1850, Alpine glaciers – now in alarming retreat – actually advanced. African and Indian monsoon systems weakened, and rain that should have fallen on hot soils dropped as more snow over Europe.

“Given the large climatic changes seen in the early 19th century, it is difficult to define a pre-industrial climate, a notion to which all our climate targets refer,” said Professor Brönnimann. “Frequent volcanic eruptions caused an actual gear shift in the global climate system.”

Commenting on the Nature finding, Mark Maslin, a climatologist at University College London, said: “Over the last 2000 years the only time the global climate has changed synchronically has been in the last 150 years when over 98% of the surface of the planet has warmed. This paper should finally stop climate change deniers claiming that the recent observed coherent global warming is part of a natural climate cycle.

“This paper shows the truly stark difference between regional and localised changes in climates of the past and the truly global effect of anthropogenic greenhouse emissions.” – Climate News Network

The planet is warming faster than ever, worldwide. Scientists know this unique climate change is not caused by nature. But they checked again, to be certain.

LONDON, 19 August, 2019 – European and US scientists have cleared up a point that has been nagging away at climate science for decades: not only is the planet warming faster than at any time in the last 2,000 years, but this unique climate change really does have neither a historic precedent nor a natural cause.

Other historic changes – the so-called Medieval Warm Period and then the “Little Ice Age” that marked the 17th to the 19th centuries – were not global. The only period in which the world’s climate has changed, everywhere and at the same time, is right now.

And other shifts in the past, marked by advancing Alpine glaciers and sustained droughts in Africa, could be pinned down to a flurry of violent volcanic activity.

The present sustained, ubiquitous warming is unique in that it can be coupled directly with the Industrial Revolution, the clearing of the forests, population growth and profligate use of fossil fuels.

The finding is part of a sustained examination of global climate history, based not just on written and pictorial records but also studies of ancient lake sediments, ice cores, tree rings and other proxy evidence assembled by an international partnership called the Past Global Changes Consortium. It is reported in the journal Nature.

“This paper should finally stop climate change deniers claiming that the recent observed coherent global warming is part of a natural climate cycle”

Research like this is a tidying-up operation. Climate scientists, conservationists, glaciologists, marine biologists, geologists and economists all know that climate change is happening, and that it is happening as a consequence of accelerated human activity over the last two centuries.

But from the start, there have always been gnawing questions: hasn’t the climate always changed? If global temperatures rose between 700 AD and 1400 AD, and then fell again, is what is happening now not part of some similar long-term cycle? And until now, that has remained without a confident, categorical answer.

So the latest study surprises nobody. But it matters, because the Nature study clarifies a point of possible confusion. There have been changes in modern human history, but none of them global and synchronous (happening at the same time). They were random fluctuations within the climate system, and even changes in solar activity or volcanic surges could not affect all of the planet at any one time.

“It’s true that during the Little Ice Age it was generally colder across the whole world,” says Raphel Neukom of the University of Bern in Switzerland, and first author, “but not everywhere at the same time. The peak periods of pre-industrial warm and cold periods occurred at different times in different places.”

And his Bern colleague Stefan Brönnimann clears up another point in a related study in the pages of Nature Geoscience.

Volcanic influence

The Little Ice Age began in Europe with no obvious trigger, but it was certainly reinforced and extended by more violent than usual volcanic activity in the tropics between 1808 and 1835. Mt Tambora in what is now Indonesia put so much ash into the stratosphere to screen sunlight and drop temperatures that 1816 became known as the Year without a Summer.

But there were also four other eruptions. Between 1820 and 1850, Alpine glaciers – now in alarming retreat – actually advanced. African and Indian monsoon systems weakened, and rain that should have fallen on hot soils dropped as more snow over Europe.

“Given the large climatic changes seen in the early 19th century, it is difficult to define a pre-industrial climate, a notion to which all our climate targets refer,” said Professor Brönnimann. “Frequent volcanic eruptions caused an actual gear shift in the global climate system.”

Commenting on the Nature finding, Mark Maslin, a climatologist at University College London, said: “Over the last 2000 years the only time the global climate has changed synchronically has been in the last 150 years when over 98% of the surface of the planet has warmed. This paper should finally stop climate change deniers claiming that the recent observed coherent global warming is part of a natural climate cycle.

“This paper shows the truly stark difference between regional and localised changes in climates of the past and the truly global effect of anthropogenic greenhouse emissions.” – Climate News Network

European Union helped to cool 2003 heatwave

Small local changes make a big difference as the temperature soars. And the European Union’s existence once cooled a vicious heatwave.

LONDON, 9 August, 2019 − Of all the political plaudits or economic brickbats hurled at the European Union, this might be the least expected: simply because it existed, it somehow ameliorated or damped down the worst of the 2003 heatwave.

This moment of extreme summer heat is believed to have caused an estimated 40,000 excess deaths and cost the European economy more than €13 billion in economic losses and infrastructure damage.

And yet it could have been worse. Had what is now a 28-nation political and economic behemoth not been formed in 1993, the way the member nations used their land would not have changed, and the heatwave might have been more intense, more severe and more destructive still.

The formation of the EU with its single market and customs union wasn’t the only political shift. The end of the Cold War and the collapse of the Soviet Union in 1991 also played a role in determining how farmers, graziers, foresters, conservationists and ministerial managers used the terrain of the European continent.

And – without thinking much about future climate shifts – farmers and foresters collectively began a series of changes that meant that what had once been farmland was abandoned, in Portugal and Spain, in eastern Europe and in Italy, as intensive production shifted to other economic zones.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe”

As more than 8% of what had been ploughed land reverted to grassland and scrub, the shallow groundwater in the abandoned soil began to act in unexpected ways. There was more evapotranspiration, which meant more cloud, which meant more reflectivity, which meant that lower levels of radiation actually scorched the landscape.

And, in turn, temperatures, as torrid as they were in the unprecedented heat that August, were damped down.

Samuel Zipper, then of the University of Victoria in Canada, now at the University of Kansas, and colleagues from Belgium and Germany report in the journal Environmental Research Letters that they used what they call “bedrock to atmosphere” computer models to simulate the way water and energy cycles shifted over western Europe between 1990 and 2010. They then made an estimate of what might have happened had there been no changes in the way the land was used.

“What we think is happening is that the agricultural abandonment led to an increase in the amount of water that plants transpired into the atmosphere, which caused increased cloud formation,” Dr Zipper said.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe.”

France spared

They found in addition that the changes in land use overall had some effect on local climate even in those places where land had not been abandoned.

They found that even France – the nation most harshly hit by the extremes of heat that summer – experienced less heat than it would have without shifts in land use further south and east.

And they confirmed that soil moisture, especially in the first metre or so of ground, played a powerful role in moderating atmospheric temperatures that in that region in that year, and in other places exposed to heat extremes since, put the very young, the elderly, the already ill and the poorly housed at ever greater risk of death in dangerous temperatures.

The scientists completed their research long before the unprecedented temperatures recorded in Western Europe this 2019 summer. Such what-if studies based on alternative histories arrive with inherent uncertainties. There is no way to conduct any convincing real life experiment that replicates the same heat wave under different landscape changes.

But the research confirms what climate scientists have been arguing for decades, and that is that the way land is used inevitably contributes to local shifts in temperature, and therefore to overall annual average warming, and inevitably to long-term, lethal and potentially catastrophic extremes. − Climate News Network

Small local changes make a big difference as the temperature soars. And the European Union’s existence once cooled a vicious heatwave.

LONDON, 9 August, 2019 − Of all the political plaudits or economic brickbats hurled at the European Union, this might be the least expected: simply because it existed, it somehow ameliorated or damped down the worst of the 2003 heatwave.

This moment of extreme summer heat is believed to have caused an estimated 40,000 excess deaths and cost the European economy more than €13 billion in economic losses and infrastructure damage.

And yet it could have been worse. Had what is now a 28-nation political and economic behemoth not been formed in 1993, the way the member nations used their land would not have changed, and the heatwave might have been more intense, more severe and more destructive still.

The formation of the EU with its single market and customs union wasn’t the only political shift. The end of the Cold War and the collapse of the Soviet Union in 1991 also played a role in determining how farmers, graziers, foresters, conservationists and ministerial managers used the terrain of the European continent.

And – without thinking much about future climate shifts – farmers and foresters collectively began a series of changes that meant that what had once been farmland was abandoned, in Portugal and Spain, in eastern Europe and in Italy, as intensive production shifted to other economic zones.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe”

As more than 8% of what had been ploughed land reverted to grassland and scrub, the shallow groundwater in the abandoned soil began to act in unexpected ways. There was more evapotranspiration, which meant more cloud, which meant more reflectivity, which meant that lower levels of radiation actually scorched the landscape.

And, in turn, temperatures, as torrid as they were in the unprecedented heat that August, were damped down.

Samuel Zipper, then of the University of Victoria in Canada, now at the University of Kansas, and colleagues from Belgium and Germany report in the journal Environmental Research Letters that they used what they call “bedrock to atmosphere” computer models to simulate the way water and energy cycles shifted over western Europe between 1990 and 2010. They then made an estimate of what might have happened had there been no changes in the way the land was used.

“What we think is happening is that the agricultural abandonment led to an increase in the amount of water that plants transpired into the atmosphere, which caused increased cloud formation,” Dr Zipper said.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe.”

France spared

They found in addition that the changes in land use overall had some effect on local climate even in those places where land had not been abandoned.

They found that even France – the nation most harshly hit by the extremes of heat that summer – experienced less heat than it would have without shifts in land use further south and east.

And they confirmed that soil moisture, especially in the first metre or so of ground, played a powerful role in moderating atmospheric temperatures that in that region in that year, and in other places exposed to heat extremes since, put the very young, the elderly, the already ill and the poorly housed at ever greater risk of death in dangerous temperatures.

The scientists completed their research long before the unprecedented temperatures recorded in Western Europe this 2019 summer. Such what-if studies based on alternative histories arrive with inherent uncertainties. There is no way to conduct any convincing real life experiment that replicates the same heat wave under different landscape changes.

But the research confirms what climate scientists have been arguing for decades, and that is that the way land is used inevitably contributes to local shifts in temperature, and therefore to overall annual average warming, and inevitably to long-term, lethal and potentially catastrophic extremes. − Climate News Network

Keep climate teaching real and honest

Many schools now routinely include climate teaching. A British teacher says her profession should tell the full story as directly as it can.

LONDON, 4 July, 2019 − There’s no escaping climate teaching. Gone are the days when the core curriculum at most schools used to consist of reading, writing and ’rithmetic, and not an awful lot more. It’s increasingly rare today to find any that don’t include the facts of life in this warming world.

But, as global youth concern over the deepening crisis manifests itself in the protests of Fridays for Future, which has earned the backing of leading climate scientists, how do teachers fulfil our obligation to encourage pupils to treat the climate as responsibly as it deserves?

What are we teaching, and how are we teaching it? What are we trying to achieve?

The past twenty years in primary and tertiary education have taught me that the answer is, and always has been, quite simple; we must keep the content real and we must teach honestly.

That means doing away with tokenistic “eco weeks” or days, and embedding climate change teaching in the day-to-day reality of core subjects.

‘Cute little projects’

There’s no doubt that special days and events are fun to do and a welcome break from teaching to the test that is becoming ever more prevalent. But they become meaningless if the message and seriousness of taking action on climate change is forgotten, or if old habits prevail.

When I saw my son learning about “rainforests” in the way I had thirty years previously, our profession’s responsibility struck home to me.

It’s not OK to treat these topics − “oceans”, “rainforests”, “habitats” or whatever − as cute little projects that end in a good assembly or great classroom display, or to have litter-picking days and then ignore our children as they emerge from the cinema leaving a trail of popcorn boxes and cups for others to clear up.

That’s not teaching that’s real and honest. But there are many resources to help us make it so.

Perhaps one of the greatest sources of support comes from organisations such as Survival, World Wide Fund for Nature, Sustainability and Environmental EducationGreenpeace, Oxfam, and the magazine New Scientist.

“Unless someone like you cares a whole awful lot, nothing is going to get better. It’s not”

There’s an argument that if our actions support people, then they will protect their environment. Survival is a great example of this. It supports indigenous people living in many threatened areas. As teachers in a small international school in Malawi, we wondered how to ensure our teaching about rainforests was indeed real and honest. We used Survival’s bank of videos and joined their campaign to support the Awá tribe of Brazil. We told the children their letters mattered and that we would send them. We did.

Half a year later, when we received an email from Survival thanking all of its supporters and sharing the good news that the forest home of the Awá was safe from loggers, we were thrilled.

The children realised they had the collective power to act and support fellow human beings on another continent. The intention to educate responsibly, the implementation through research, discussion and formal letter-writing, all made an incredible impact.

A second wonderful resource comes from every teacher’s favourite – the book. It is stories that make us human and give us that safe place to explore, question and reason.

Take Dr.Seuss’ The Lorax, in which he reminds us: “Unless someone like you cares a whole awful lot, nothing is going to get better. It’s not.” This was written in 1971, so it lends itself to examining why we are now reaching crisis point in 2019, even though warnings about how our behaviour is affecting our planet were resounding decades ago.

Music matters

The Morningside Centre for Teaching Social Responsibility  has a list of further fictional texts to explore climate change in the classroom. I’d also recommend Lynne Cherry’s The Great Kapok Tree, which could allow the use of drama and music to explore the impact of individuals on the planet.

As the arts become more and more sidelined, it’s important to remember just how they help to deliver messages about tackling issues. The rising movement of protest choirs is a great place to start looking at how language and music can combine to make a point peacefully, non-violently but powerfully.

Finally, don’t forget the numbers. Those we bring into the classroom should be real and meaningful too. Striking infographics can help to tell the story for you, supporting the teaching of mathematics in greater depth, or providing a vivid portrayal of how concerned about climate change different countries are.

Our children’s and young people’s worries about climate change are justified. As their teachers, we’re privileged to empower them further. Keeping our teaching real and honest matters: there’ll be no point in passing exams if there’s no planet where they can live out their dreams.

The world’s young people have already worked this one out. Let’s take our role seriously and help them to help everyone make the changes that we so urgently need. − Climate News Network

* * * * *

Anne Kagoya, a primary school teacher with 22 years’ experience, has worked in state sector schools in Scotland, England and the Falkland Islands (also known as the Malvinas), and at an international primary school and teacher training college in Malawi

Email: fabulouslyrelevant@gmail.com

Many schools now routinely include climate teaching. A British teacher says her profession should tell the full story as directly as it can.

LONDON, 4 July, 2019 − There’s no escaping climate teaching. Gone are the days when the core curriculum at most schools used to consist of reading, writing and ’rithmetic, and not an awful lot more. It’s increasingly rare today to find any that don’t include the facts of life in this warming world.

But, as global youth concern over the deepening crisis manifests itself in the protests of Fridays for Future, which has earned the backing of leading climate scientists, how do teachers fulfil our obligation to encourage pupils to treat the climate as responsibly as it deserves?

What are we teaching, and how are we teaching it? What are we trying to achieve?

The past twenty years in primary and tertiary education have taught me that the answer is, and always has been, quite simple; we must keep the content real and we must teach honestly.

That means doing away with tokenistic “eco weeks” or days, and embedding climate change teaching in the day-to-day reality of core subjects.

‘Cute little projects’

There’s no doubt that special days and events are fun to do and a welcome break from teaching to the test that is becoming ever more prevalent. But they become meaningless if the message and seriousness of taking action on climate change is forgotten, or if old habits prevail.

When I saw my son learning about “rainforests” in the way I had thirty years previously, our profession’s responsibility struck home to me.

It’s not OK to treat these topics − “oceans”, “rainforests”, “habitats” or whatever − as cute little projects that end in a good assembly or great classroom display, or to have litter-picking days and then ignore our children as they emerge from the cinema leaving a trail of popcorn boxes and cups for others to clear up.

That’s not teaching that’s real and honest. But there are many resources to help us make it so.

Perhaps one of the greatest sources of support comes from organisations such as Survival, World Wide Fund for Nature, Sustainability and Environmental EducationGreenpeace, Oxfam, and the magazine New Scientist.

“Unless someone like you cares a whole awful lot, nothing is going to get better. It’s not”

There’s an argument that if our actions support people, then they will protect their environment. Survival is a great example of this. It supports indigenous people living in many threatened areas. As teachers in a small international school in Malawi, we wondered how to ensure our teaching about rainforests was indeed real and honest. We used Survival’s bank of videos and joined their campaign to support the Awá tribe of Brazil. We told the children their letters mattered and that we would send them. We did.

Half a year later, when we received an email from Survival thanking all of its supporters and sharing the good news that the forest home of the Awá was safe from loggers, we were thrilled.

The children realised they had the collective power to act and support fellow human beings on another continent. The intention to educate responsibly, the implementation through research, discussion and formal letter-writing, all made an incredible impact.

A second wonderful resource comes from every teacher’s favourite – the book. It is stories that make us human and give us that safe place to explore, question and reason.

Take Dr.Seuss’ The Lorax, in which he reminds us: “Unless someone like you cares a whole awful lot, nothing is going to get better. It’s not.” This was written in 1971, so it lends itself to examining why we are now reaching crisis point in 2019, even though warnings about how our behaviour is affecting our planet were resounding decades ago.

Music matters

The Morningside Centre for Teaching Social Responsibility  has a list of further fictional texts to explore climate change in the classroom. I’d also recommend Lynne Cherry’s The Great Kapok Tree, which could allow the use of drama and music to explore the impact of individuals on the planet.

As the arts become more and more sidelined, it’s important to remember just how they help to deliver messages about tackling issues. The rising movement of protest choirs is a great place to start looking at how language and music can combine to make a point peacefully, non-violently but powerfully.

Finally, don’t forget the numbers. Those we bring into the classroom should be real and meaningful too. Striking infographics can help to tell the story for you, supporting the teaching of mathematics in greater depth, or providing a vivid portrayal of how concerned about climate change different countries are.

Our children’s and young people’s worries about climate change are justified. As their teachers, we’re privileged to empower them further. Keeping our teaching real and honest matters: there’ll be no point in passing exams if there’s no planet where they can live out their dreams.

The world’s young people have already worked this one out. Let’s take our role seriously and help them to help everyone make the changes that we so urgently need. − Climate News Network

* * * * *

Anne Kagoya, a primary school teacher with 22 years’ experience, has worked in state sector schools in Scotland, England and the Falkland Islands (also known as the Malvinas), and at an international primary school and teacher training college in Malawi

Email: fabulouslyrelevant@gmail.com

Paris treaty would cut US heat peril

Even in rich, air-conditioned America, people die in extreme heat. This US heat peril means more will die. Political decisions will decide how many more.

LONDON, 18 June, 2019 − British scientists have identified a way in which President Trump could save thousands of American lives from the US heat peril. All he needs to do is honour the Paris Agreement of 2015 to keep global warming to “well below” 2°C above the planetary average that has endured for most of human history.

If the global thermometer is kept at the lowest possible level of a rise of 1.5°C – rather than the average rise of 3°C of human-triggered heating that the planet seems on course to experience by the end of the century − then this simple decision would prevent up to 2,720 extra deaths in any city that experienced the kind of potentially-deadly heatwave that comes along every thirty years or so, according to a new study in the journal Scientific Advances.

Researchers focused on 15 US cities from where records yielded reliable data that could answer questions about climate and health. These were Atlanta, Boston, Chicago, Dallas, Detroit, Houston, Los Angeles, Miami, New York City, Philadelphia, Phoenix, San Francisco, Seattle, St Louis and Washington DC.

They then used statistical tools to calculate the number of deaths that could be expected in the kind of extremely hot summers occasionally recorded in big cities at almost any latitude, and likely to recur with greater frequency and intensity as global average temperatures rise.

Poor face biggest risk

They found what they call “compelling evidence” that limiting global warming to 1.5°C would prevent significantly more excess deaths among the old, the poor or the already-ill in the US than a 2°C limit, and many more than the 3°C or more if governments continue on a “business as usual” course and humans burn even more fossil fuels, to emit ever more greenhouse gases into the atmosphere.

President Trump has promised to withdraw the US from the Paris Agreement signed by his predecessor, President Obama. But the study is a reminder that extremes of heat bring often devastating losses of life even in relatively well-off communities in the world’s temperate zones. Those most at risk remain the poorest urban dwellers in the world’s warmest places.

Researchers have warned that by 2100, one person in three in Africa’s cities could be exposed to intolerable levels of heat, and have identified other zones where heat and humidity could conspire to reach lethal levels: these include the North China plain and the Gulf region.

US scientists recently numbered 27 ways in which extremes of heat could claim lives and some of these are likely to apply to cities in the normally cooler parts of the globe.

“Limiting global warming to 1.5°C would prevent significantly more excess deaths among the old, the poor or the already-ill in the US than a 2°C limit”

Health authorities have identified deaths attributable to heat in London and Paris in 2003, and European scientists have warned that more murderous heat waves are on the way.

And although the Science Advances research concentrates on what could happen in American cities tomorrow, a second and separate study led by US scientists has just established a direct link between intense heat events and extra deaths in the Nevada city of Las Vegas, just in the last 10 years.

They report in the International Journal of Environmental Science and Technology that they found a steady increase in the severity and frequency of excess heat in the city since 1980, and a matching increase in numbers of deaths.

Between 2007 and 2016, there were 437 heat-related deaths in the city, with the greatest number in 2016, the year of the highest measures of heat for the past 35 years. − Climate News Network

Even in rich, air-conditioned America, people die in extreme heat. This US heat peril means more will die. Political decisions will decide how many more.

LONDON, 18 June, 2019 − British scientists have identified a way in which President Trump could save thousands of American lives from the US heat peril. All he needs to do is honour the Paris Agreement of 2015 to keep global warming to “well below” 2°C above the planetary average that has endured for most of human history.

If the global thermometer is kept at the lowest possible level of a rise of 1.5°C – rather than the average rise of 3°C of human-triggered heating that the planet seems on course to experience by the end of the century − then this simple decision would prevent up to 2,720 extra deaths in any city that experienced the kind of potentially-deadly heatwave that comes along every thirty years or so, according to a new study in the journal Scientific Advances.

Researchers focused on 15 US cities from where records yielded reliable data that could answer questions about climate and health. These were Atlanta, Boston, Chicago, Dallas, Detroit, Houston, Los Angeles, Miami, New York City, Philadelphia, Phoenix, San Francisco, Seattle, St Louis and Washington DC.

They then used statistical tools to calculate the number of deaths that could be expected in the kind of extremely hot summers occasionally recorded in big cities at almost any latitude, and likely to recur with greater frequency and intensity as global average temperatures rise.

Poor face biggest risk

They found what they call “compelling evidence” that limiting global warming to 1.5°C would prevent significantly more excess deaths among the old, the poor or the already-ill in the US than a 2°C limit, and many more than the 3°C or more if governments continue on a “business as usual” course and humans burn even more fossil fuels, to emit ever more greenhouse gases into the atmosphere.

President Trump has promised to withdraw the US from the Paris Agreement signed by his predecessor, President Obama. But the study is a reminder that extremes of heat bring often devastating losses of life even in relatively well-off communities in the world’s temperate zones. Those most at risk remain the poorest urban dwellers in the world’s warmest places.

Researchers have warned that by 2100, one person in three in Africa’s cities could be exposed to intolerable levels of heat, and have identified other zones where heat and humidity could conspire to reach lethal levels: these include the North China plain and the Gulf region.

US scientists recently numbered 27 ways in which extremes of heat could claim lives and some of these are likely to apply to cities in the normally cooler parts of the globe.

“Limiting global warming to 1.5°C would prevent significantly more excess deaths among the old, the poor or the already-ill in the US than a 2°C limit”

Health authorities have identified deaths attributable to heat in London and Paris in 2003, and European scientists have warned that more murderous heat waves are on the way.

And although the Science Advances research concentrates on what could happen in American cities tomorrow, a second and separate study led by US scientists has just established a direct link between intense heat events and extra deaths in the Nevada city of Las Vegas, just in the last 10 years.

They report in the International Journal of Environmental Science and Technology that they found a steady increase in the severity and frequency of excess heat in the city since 1980, and a matching increase in numbers of deaths.

Between 2007 and 2016, there were 437 heat-related deaths in the city, with the greatest number in 2016, the year of the highest measures of heat for the past 35 years. − Climate News Network

African city heat is set to grow intolerably

Up to a third of urban dwellers could soon face extreme African city heat and humidity. Risks could at worst multiply 50-fold.

LONDON, 11 June, 2019 – An entire continent faces lethal conditions for many of its people: by 2090, one person in three can expect African city heat in the great conurbations severe enough to expose them to potentially deadly temperatures.

That is: the number of days in which the apparent temperature – a notional balance of thermometer-measured heat and maximum humidity – could reach or surpass 40.6°C will increase dramatically, and the days when individuals could be at risk could in some scenarios multiply 50-fold.

The scientists selected this “apparent” temperature of 40.6°C because it is significantly beyond the natural temperature of the human body, which must then be kept cool by perspiration. This is possible in arid climates.

But as humidity goes up – and with each 1°C rise in temperature, the capacity of the air to hold moisture rises by 7% – cooling by perspiration becomes less efficient.

So at this notionally-defined apparent temperature, people who cannot retreat to air-conditioned or cooler, shadier places could die. Heat kills: researchers recently counted 27 ways in which extreme temperatures could claim lives.

“If we follow the Paris Agreement, we’ll halve the number of people at risk in 2090, which is encouraging”

And more, and more intense and prolonged heat waves are on the way, and with them episodes of potentially extreme humidity. By 2100, according to some studies, certain regions of the planet could become dangerous habitat.

European scientists report in the journal Earth’s Future that they considered the hazard for just one, rapidly-growing continent: Africa. They selected 173 cities of more than 300,000 people in 43 nations across a range of climates, from Algiers on the Mediterranean to the burgeoning monsoon cities of the equatorial west coast, such as Lagos and Kinshasa, the drier east African states, and the relatively mild townships of Southern Africa.

They then considered how much cities might grow, by migration or birth-rate increases, and how they might develop. Then they factored in a range of climate scenarios and looked at possible forecasts for the years 2030, 2060 and 2090.

They found that because of population growth, the numbers of days on which people could be at risk – measured in person-days (one person working for one full day) – would in any case increase.

Sharper rise

“In the best case, 20 billion person-days will be affected by 2030, compared with 4.2bn in 2010 – a jump, in other words, of 376%” said Guillaume Rohat, of the University of Geneva, who led the study. “This figure climbs to 45bn in 2060 (up 971%) and reaches 86bn in 2090 (up 1947%).

And that is the best-case scenario. When the researchers factored in the steepest population increases, the most rapid growth of the cities and the worst disturbances in climate, the figures rose more sharply. By 2030, 26 billion, a fivefold increase, could be at risk, 95bn in 2060 and 217 bn in 2090. This is an increase of 4967%, or nearly 50-fold.

The researchers assumed that not everybody in their 173 cities would be exposed to dangerous levels of heat. Were that to happen, the number of person-days could hit 647 billion. But the researchers made a conservative estimate of one in three people who would be exposed to a minimum temperature of 40.6°C.

Research of this kind makes assumptions about how the climate is going to change, and separately about how nations are going to develop, how populations are going to grow and change, and how governments are going to respond to the climate emergency, and the authors recognise the problems.

Conservative conclusions

The sample is biased towards the larger cities. Their calculations don’t include predictions for capital investment. But the researchers say their conclusions are if anything conservative. They do not, for instance, factor in the notorious urban heat island effect that tends to make cities 3°C or more hotter than the surrounding countryside, and therefore even more dangerous.

The good news to emerge from the study is that concerted action, by governments and civic authorities, can reduce the risk. Were nations to stick to an agreement made by 195 of them in Paris in 2015, and keep global temperature rise to “well below” 2°C, the final exposure hazard would be reduced by 48%.

“This proves that if we follow the Paris Agreement, we’ll halve the number of people at risk in 2090, which is encouraging,” said Rohat.

“We can see the importance of the UN Sustainable Development Goals: access to education, a drop in the number of children per woman, developments in the standard of living and so on.” – Climate News Network

Up to a third of urban dwellers could soon face extreme African city heat and humidity. Risks could at worst multiply 50-fold.

LONDON, 11 June, 2019 – An entire continent faces lethal conditions for many of its people: by 2090, one person in three can expect African city heat in the great conurbations severe enough to expose them to potentially deadly temperatures.

That is: the number of days in which the apparent temperature – a notional balance of thermometer-measured heat and maximum humidity – could reach or surpass 40.6°C will increase dramatically, and the days when individuals could be at risk could in some scenarios multiply 50-fold.

The scientists selected this “apparent” temperature of 40.6°C because it is significantly beyond the natural temperature of the human body, which must then be kept cool by perspiration. This is possible in arid climates.

But as humidity goes up – and with each 1°C rise in temperature, the capacity of the air to hold moisture rises by 7% – cooling by perspiration becomes less efficient.

So at this notionally-defined apparent temperature, people who cannot retreat to air-conditioned or cooler, shadier places could die. Heat kills: researchers recently counted 27 ways in which extreme temperatures could claim lives.

“If we follow the Paris Agreement, we’ll halve the number of people at risk in 2090, which is encouraging”

And more, and more intense and prolonged heat waves are on the way, and with them episodes of potentially extreme humidity. By 2100, according to some studies, certain regions of the planet could become dangerous habitat.

European scientists report in the journal Earth’s Future that they considered the hazard for just one, rapidly-growing continent: Africa. They selected 173 cities of more than 300,000 people in 43 nations across a range of climates, from Algiers on the Mediterranean to the burgeoning monsoon cities of the equatorial west coast, such as Lagos and Kinshasa, the drier east African states, and the relatively mild townships of Southern Africa.

They then considered how much cities might grow, by migration or birth-rate increases, and how they might develop. Then they factored in a range of climate scenarios and looked at possible forecasts for the years 2030, 2060 and 2090.

They found that because of population growth, the numbers of days on which people could be at risk – measured in person-days (one person working for one full day) – would in any case increase.

Sharper rise

“In the best case, 20 billion person-days will be affected by 2030, compared with 4.2bn in 2010 – a jump, in other words, of 376%” said Guillaume Rohat, of the University of Geneva, who led the study. “This figure climbs to 45bn in 2060 (up 971%) and reaches 86bn in 2090 (up 1947%).

And that is the best-case scenario. When the researchers factored in the steepest population increases, the most rapid growth of the cities and the worst disturbances in climate, the figures rose more sharply. By 2030, 26 billion, a fivefold increase, could be at risk, 95bn in 2060 and 217 bn in 2090. This is an increase of 4967%, or nearly 50-fold.

The researchers assumed that not everybody in their 173 cities would be exposed to dangerous levels of heat. Were that to happen, the number of person-days could hit 647 billion. But the researchers made a conservative estimate of one in three people who would be exposed to a minimum temperature of 40.6°C.

Research of this kind makes assumptions about how the climate is going to change, and separately about how nations are going to develop, how populations are going to grow and change, and how governments are going to respond to the climate emergency, and the authors recognise the problems.

Conservative conclusions

The sample is biased towards the larger cities. Their calculations don’t include predictions for capital investment. But the researchers say their conclusions are if anything conservative. They do not, for instance, factor in the notorious urban heat island effect that tends to make cities 3°C or more hotter than the surrounding countryside, and therefore even more dangerous.

The good news to emerge from the study is that concerted action, by governments and civic authorities, can reduce the risk. Were nations to stick to an agreement made by 195 of them in Paris in 2015, and keep global temperature rise to “well below” 2°C, the final exposure hazard would be reduced by 48%.

“This proves that if we follow the Paris Agreement, we’ll halve the number of people at risk in 2090, which is encouraging,” said Rohat.

“We can see the importance of the UN Sustainable Development Goals: access to education, a drop in the number of children per woman, developments in the standard of living and so on.” – Climate News Network

Global warming: Human activity is the cause

Fresh studies have again confirmed a vital fact about global warming: human activity is its cause. Science questions its own findings, which is why we should trust it.

LONDON, 29 May, 2019 − British scientists have re-asserted an essential reality about global warming: human activity, not slow-acting and so far unidentified natural cycles in the world’s oceans, is its cause.

That activity – including ever-increasing combustion of fossil fuels as well as the devastation of the natural forest – is enough to account for almost all the warming over the last century.

Researchers from the University of Oxford report in the Journal of Climate that they looked at all the available observed land and ocean temperature data since 1850.

They matched this not just with greenhouse gas concentrations but also with records of volcanic eruptions, solar activity and air pollution peaks – all of which affect temperature readings.

“This sounds boring, but sometimes boring results are important”

And their analysis once again confirms a finding first proposed in the 19th century by the Swedish Nobel Laureate Svante Arrhenius: that greenhouse gases are enough to explain the big picture of a slowly but inexorably heating world. Slow-acting global oceanic cycles would have had little or no influence.

“Our study showed there are no hidden drivers of global mean temperature. The temperature change we observe is due to the drivers we know,” said Friederike Otto of Oxford’s Environmental Change Institute.

“This sounds boring, but sometimes boring results are important.”

Studies of this kind are a reminder of why science may, ultimately, be trusted: it takes nothing for granted. Researchers tend to go back and question their own and each other’s published conclusions. In the case of climate research, this has become almost a nervous tic.

Untidy evidence

But it is necessary because climate science in particular remains a work in progress: we live in a crowded, dynamic world and the evidence is always untidy and sometimes confusing, the interpretation of the data potentially subject to bias, and above all each conclusion is bedevilled by the question: is there something – some feedback, some factor, some actor – nobody has yet spotted?

So studies that confirm the big picture are always welcome, especially one that says: we can find no unknown factors. That is why boring results are important. It means that what humans do will change the outcome.

“In this case, it means we will not see any surprises when these drivers – such as gas emissions − change,” said Dr Otto.

“In good news, this means that when greenhouse concentrations go down, temperatures will do so as predicted; the bad news is there is nothing that saves us from temperatures going up as forecasted if we fail drastically to cut greenhouse gas emissions.” − Climate News Network

Fresh studies have again confirmed a vital fact about global warming: human activity is its cause. Science questions its own findings, which is why we should trust it.

LONDON, 29 May, 2019 − British scientists have re-asserted an essential reality about global warming: human activity, not slow-acting and so far unidentified natural cycles in the world’s oceans, is its cause.

That activity – including ever-increasing combustion of fossil fuels as well as the devastation of the natural forest – is enough to account for almost all the warming over the last century.

Researchers from the University of Oxford report in the Journal of Climate that they looked at all the available observed land and ocean temperature data since 1850.

They matched this not just with greenhouse gas concentrations but also with records of volcanic eruptions, solar activity and air pollution peaks – all of which affect temperature readings.

“This sounds boring, but sometimes boring results are important”

And their analysis once again confirms a finding first proposed in the 19th century by the Swedish Nobel Laureate Svante Arrhenius: that greenhouse gases are enough to explain the big picture of a slowly but inexorably heating world. Slow-acting global oceanic cycles would have had little or no influence.

“Our study showed there are no hidden drivers of global mean temperature. The temperature change we observe is due to the drivers we know,” said Friederike Otto of Oxford’s Environmental Change Institute.

“This sounds boring, but sometimes boring results are important.”

Studies of this kind are a reminder of why science may, ultimately, be trusted: it takes nothing for granted. Researchers tend to go back and question their own and each other’s published conclusions. In the case of climate research, this has become almost a nervous tic.

Untidy evidence

But it is necessary because climate science in particular remains a work in progress: we live in a crowded, dynamic world and the evidence is always untidy and sometimes confusing, the interpretation of the data potentially subject to bias, and above all each conclusion is bedevilled by the question: is there something – some feedback, some factor, some actor – nobody has yet spotted?

So studies that confirm the big picture are always welcome, especially one that says: we can find no unknown factors. That is why boring results are important. It means that what humans do will change the outcome.

“In this case, it means we will not see any surprises when these drivers – such as gas emissions − change,” said Dr Otto.

“In good news, this means that when greenhouse concentrations go down, temperatures will do so as predicted; the bad news is there is nothing that saves us from temperatures going up as forecasted if we fail drastically to cut greenhouse gas emissions.” − Climate News Network

No more climate change: it’s now a crisis

What’s in a name? A lot, The Guardian says: it’s ditching mentions of climate change and switching to sterner language.

LONDON, 24 May, 2019 − Talk about climate change, and there’s a good chance that people will know what you’re referring to, even if they don’t share your concerns about it.

But for one UK-based newspaper, The Guardian, “climate change” is now frowned upon, though it’s not formally banned. The paper’s house style guide recommends that its journalists should instead use such terms as “climate crisis” and “global heating”.

The Guardian has updated the style guide to introduce terms that it thinks more accurately describe the environmental crises confronting the world. So out goes “climate change”, to be replaced by the preferred terms, “climate emergency, crisis or breakdown”. “Global heating” replaces “global warming”.

“We want to ensure that we are being scientifically precise, while also communicating clearly with readers on this very important issue,” says the editor-in-chief, Katharine Viner. “The phrase ‘climate change’, for example, sounds rather passive and gentle when what scientists are talking about is a catastrophe for humanity.”

“The climate crisis is no longer a future problem – we need to tackle it now, and every day matters”

The United Nations secretary-general, António Guterres, spoke of a “climate crisis” last September, adding: “We face a direct existential threat.” The climate scientist Professor Hans Joachim Schellnhuber, a former adviser to Angela Merkel, the EU and the pope, also uses the term.

In December Professor Richard Betts, who leads the UK Met Office’s climate research, said “global heating” was a more accurate term than “global warming” to describe what is now happening. British Members of Parliament recently endorsed the opposition Labour Party’s declaration of a climate emergency.

The scale of the climate and wildlife crises has been starkly spelt out by two chilling reports from the world’s scientists. In October 2018 they said carbon emissions must halve by 2030 to avoid even greater risks of drought, floods, extreme heat and poverty for hundreds of millions of people. In May 2019 they said human society is at risk from the accelerating annihilation of wildlife and destruction of the ecosystems that support all life on Earth.

Frequent errors

Other terms have also been updated by the Guardian. It now refers to “wildlife” rather than “biodiversity”, “fish populations” instead of “fish stocks”, and “climate science denier” rather than “climate sceptic”.

The BBC has put a formal end to a practice widely used for 30 years: it accepted last September that it gets coverage of climate change “wrong too often”, telling its staff: “You do not need a ‘denier’ to balance the debate.”

Greta Thunberg, the Swedish teenager who has inspired school strikes for the climate around the globe, said recently: “It’s 2019. Can we all now call it what it is: climate breakdown, climate crisis, climate emergency, ecological breakdown, ecological crisis and ecological emergency?”

The update to the Guardian’s style guide follows the recent addition of the global carbon dioxide level to its daily weather pages. “Levels of CO2 in the atmosphere have risen so dramatically – including a measure of that in our daily weather report is symbolic of what human activity is doing to our climate,” said Katharine Viner at the time.

Daily reminders

“People need reminding that the climate crisis is no longer a future problem – we need to tackle it now, and every day matters.”

The Guardian provides thorough coverage of the global environment, objective reporting and informed and pointed comment. The Climate News Network has since its start been part of the Guardian Environment Network.  The newspaper is one of the best-respected and most widely used international sources of information on the crises of the climate and the natural world.

Many of its competitors will be keen to see what difference in people’s perceptions of the crises follow from the name changes, and whether clearer and more deliberately assertive language prompts bolder action.

“Scientists, the media, and policymakers must, of course, distinguish when we’re talking about the fact of what’s happening (‘climate change’) from the opinion about how bad it is (‘climate crisis’),” Peter Gleick, a climate scientist who co-founded the Pacific Institute, told the US-based Earther website in an email.

Facts – and opinions

“Perhaps that’s a minor quibble, but when I speak in public, I try hard to present the ‘facts’ about climate change and then make clear those facts inform my opinion about how bad the problem is, and will be (we face a ‘climate crisis’).”

Several decades ago people didn’t talk much about climate change: they knew what was happening as global warming. When that was junked, to recognise that some parts of the globe were actually cooling as others warmed, it was certainly a move to something more scientifically accurate.

Climate deniers, though, said that there was no evidence of warming, and that by using the phrase “climate change” scientists were admitting that they had got the science wrong.

Remember the no-nonsense approach of the nursery rhyme character Humpty Dumpty: “When I use a word, it means just what I choose it to mean − neither more nor less.” Words can be slippery, and dangerous. − Climate News Network

What’s in a name? A lot, The Guardian says: it’s ditching mentions of climate change and switching to sterner language.

LONDON, 24 May, 2019 − Talk about climate change, and there’s a good chance that people will know what you’re referring to, even if they don’t share your concerns about it.

But for one UK-based newspaper, The Guardian, “climate change” is now frowned upon, though it’s not formally banned. The paper’s house style guide recommends that its journalists should instead use such terms as “climate crisis” and “global heating”.

The Guardian has updated the style guide to introduce terms that it thinks more accurately describe the environmental crises confronting the world. So out goes “climate change”, to be replaced by the preferred terms, “climate emergency, crisis or breakdown”. “Global heating” replaces “global warming”.

“We want to ensure that we are being scientifically precise, while also communicating clearly with readers on this very important issue,” says the editor-in-chief, Katharine Viner. “The phrase ‘climate change’, for example, sounds rather passive and gentle when what scientists are talking about is a catastrophe for humanity.”

“The climate crisis is no longer a future problem – we need to tackle it now, and every day matters”

The United Nations secretary-general, António Guterres, spoke of a “climate crisis” last September, adding: “We face a direct existential threat.” The climate scientist Professor Hans Joachim Schellnhuber, a former adviser to Angela Merkel, the EU and the pope, also uses the term.

In December Professor Richard Betts, who leads the UK Met Office’s climate research, said “global heating” was a more accurate term than “global warming” to describe what is now happening. British Members of Parliament recently endorsed the opposition Labour Party’s declaration of a climate emergency.

The scale of the climate and wildlife crises has been starkly spelt out by two chilling reports from the world’s scientists. In October 2018 they said carbon emissions must halve by 2030 to avoid even greater risks of drought, floods, extreme heat and poverty for hundreds of millions of people. In May 2019 they said human society is at risk from the accelerating annihilation of wildlife and destruction of the ecosystems that support all life on Earth.

Frequent errors

Other terms have also been updated by the Guardian. It now refers to “wildlife” rather than “biodiversity”, “fish populations” instead of “fish stocks”, and “climate science denier” rather than “climate sceptic”.

The BBC has put a formal end to a practice widely used for 30 years: it accepted last September that it gets coverage of climate change “wrong too often”, telling its staff: “You do not need a ‘denier’ to balance the debate.”

Greta Thunberg, the Swedish teenager who has inspired school strikes for the climate around the globe, said recently: “It’s 2019. Can we all now call it what it is: climate breakdown, climate crisis, climate emergency, ecological breakdown, ecological crisis and ecological emergency?”

The update to the Guardian’s style guide follows the recent addition of the global carbon dioxide level to its daily weather pages. “Levels of CO2 in the atmosphere have risen so dramatically – including a measure of that in our daily weather report is symbolic of what human activity is doing to our climate,” said Katharine Viner at the time.

Daily reminders

“People need reminding that the climate crisis is no longer a future problem – we need to tackle it now, and every day matters.”

The Guardian provides thorough coverage of the global environment, objective reporting and informed and pointed comment. The Climate News Network has since its start been part of the Guardian Environment Network.  The newspaper is one of the best-respected and most widely used international sources of information on the crises of the climate and the natural world.

Many of its competitors will be keen to see what difference in people’s perceptions of the crises follow from the name changes, and whether clearer and more deliberately assertive language prompts bolder action.

“Scientists, the media, and policymakers must, of course, distinguish when we’re talking about the fact of what’s happening (‘climate change’) from the opinion about how bad it is (‘climate crisis’),” Peter Gleick, a climate scientist who co-founded the Pacific Institute, told the US-based Earther website in an email.

Facts – and opinions

“Perhaps that’s a minor quibble, but when I speak in public, I try hard to present the ‘facts’ about climate change and then make clear those facts inform my opinion about how bad the problem is, and will be (we face a ‘climate crisis’).”

Several decades ago people didn’t talk much about climate change: they knew what was happening as global warming. When that was junked, to recognise that some parts of the globe were actually cooling as others warmed, it was certainly a move to something more scientifically accurate.

Climate deniers, though, said that there was no evidence of warming, and that by using the phrase “climate change” scientists were admitting that they had got the science wrong.

Remember the no-nonsense approach of the nursery rhyme character Humpty Dumpty: “When I use a word, it means just what I choose it to mean − neither more nor less.” Words can be slippery, and dangerous. − Climate News Network

Crops at risk from changing climate

Global warming could bring yet more challenges to a hungry world. New studies have identified precise ways in which a changing climate puts crops at risk.

LONDON, 14 May, 2019 – Climate change is leaving crops at risk. Driven by global warming – and with it ever greater extremes of heat, drought and rainfall – the rising mercury can explain up to half of all variations in harvest yields worldwide.

Unusually cold nights, ever greater numbers of extremely hot summer days, weeks with no rainfall, or torrents of storm-driven precipitation, account for somewhere between a fifth to 49% of yield losses for maize, rice, spring wheat and soy beans.

And once international scientists had eliminated the effect of temperature averages across the whole growing season, they still found that heatwaves, drought and torrential downfall accounted for 18% to 43% of losses.

In a second study, US researchers have a warning for the Midwest’s maize farmers: too much rain is just as bad for the harvest as too much heat and a long dry spell.

“While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption … making it critical for food security”

In a third study, British researchers have identified a new climate hazard for one of the tropical world’s staples: climate change has heightened the risk of a devastating fungal infection that is already ravaging banana plantations in Latin America and the Caribbean.

The impact of climate change driven by global warming fuelled by profligate fossil fuel use had been worrying ministries and agricultural researchers for years: more carbon dioxide should and sometimes could mean a greener world.

More warmth and earlier springs mean a longer growing season with lower risks of late frost. A warmer atmosphere can hold more moisture, which means ultimately more rainfall.

But the average rise in temperature worldwide of just 1°C in the last century is exactly that: an average. What cities and countryside have observed is an increase both in the number and intensity of potentially lethal heatwaves, of longer and more frequent parching in those landscapes that are normally dry, with heavier downpours in places that can depend on reliable rainfall.

Knowledge allows preparation

In Europe, the US and Africa, researchers have started to measure the cost to the grains, pulses and tubers that feed 7.7 billion people now, and will have to feed 9bn later this century.

Scientists in Australia, Germany, Spain, Switzerland and the US report in the journal Environmental Research Letters that they developed a machine-learning algorithm to make sense of climate data and harvest data collected worldwide from 1961 to 2008.

The aim was to isolate the factors within climate change that might affect harvests, on the principle that if farmers know the hazards, they can prepare.

“Interestingly, we found that the most important climate factors for yield anomalies were related to temperature, not precipitation, as one could expect, with average growing season temperature and temperature extremes playing a dominant role in predicting crop yields,” said Elisabeth Vogel of the University of Melbourne, who led the study.

Big picture reached

Nowhere was this more visible than in the figures for maize yield in Africa. “While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption – compared to just 3% in North America – making it critical for food security in the region.”

Dr Vogel and her colleagues looked at crop yields, mean seasonal temperatures, extremes and regions to arrive at their big picture. But impacts of extremes vary according to region, soil, latitude and other factors too.

US scientists report in the journal Global Change Biology that yield statistics and crop insurance data from 1981 to 2016 on the Midwest maize harvest told them a slightly different story. In some years excessive rain reduced the corn yield by as much as 34%; drought and heat in turn could be linked to losses of 37%. It depended on where the crop was grown.

“As rainfall becomes more extreme, crop insurance needs to evolve to better meet planting challenges faced by farmers,” said Gary Schnitkey of the University of Urbana-Champaign, one of the authors.

Bananas in danger

And British scientists report in the Philosophical Transactions of the Royal Society B that changes in temperature and moisture linked to global warming could be bad for the banana crop.

These have increased the risk of infection by the fungus Pseudocercospora fijiensis, or Black Sigatoka disease, by more than 44% in Latin America and the Caribbean. The disease can reduce yield in infected plants by up to 80%.

“Climate change has made temperatures better for spore germination and growth, and made crop canopies wetter, raising the risk of Black Sigatoka infection in many banana-growing areas of Latin America,” said Daniel Bebber, of the University of Exeter.

“While fungus is likely to have been introduced to Honduras on plants imported from Asia for breeding research, our models indicate that climate change over the past 60 years has exacerbated its impact.” – Climate News Network

Global warming could bring yet more challenges to a hungry world. New studies have identified precise ways in which a changing climate puts crops at risk.

LONDON, 14 May, 2019 – Climate change is leaving crops at risk. Driven by global warming – and with it ever greater extremes of heat, drought and rainfall – the rising mercury can explain up to half of all variations in harvest yields worldwide.

Unusually cold nights, ever greater numbers of extremely hot summer days, weeks with no rainfall, or torrents of storm-driven precipitation, account for somewhere between a fifth to 49% of yield losses for maize, rice, spring wheat and soy beans.

And once international scientists had eliminated the effect of temperature averages across the whole growing season, they still found that heatwaves, drought and torrential downfall accounted for 18% to 43% of losses.

In a second study, US researchers have a warning for the Midwest’s maize farmers: too much rain is just as bad for the harvest as too much heat and a long dry spell.

“While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption … making it critical for food security”

In a third study, British researchers have identified a new climate hazard for one of the tropical world’s staples: climate change has heightened the risk of a devastating fungal infection that is already ravaging banana plantations in Latin America and the Caribbean.

The impact of climate change driven by global warming fuelled by profligate fossil fuel use had been worrying ministries and agricultural researchers for years: more carbon dioxide should and sometimes could mean a greener world.

More warmth and earlier springs mean a longer growing season with lower risks of late frost. A warmer atmosphere can hold more moisture, which means ultimately more rainfall.

But the average rise in temperature worldwide of just 1°C in the last century is exactly that: an average. What cities and countryside have observed is an increase both in the number and intensity of potentially lethal heatwaves, of longer and more frequent parching in those landscapes that are normally dry, with heavier downpours in places that can depend on reliable rainfall.

Knowledge allows preparation

In Europe, the US and Africa, researchers have started to measure the cost to the grains, pulses and tubers that feed 7.7 billion people now, and will have to feed 9bn later this century.

Scientists in Australia, Germany, Spain, Switzerland and the US report in the journal Environmental Research Letters that they developed a machine-learning algorithm to make sense of climate data and harvest data collected worldwide from 1961 to 2008.

The aim was to isolate the factors within climate change that might affect harvests, on the principle that if farmers know the hazards, they can prepare.

“Interestingly, we found that the most important climate factors for yield anomalies were related to temperature, not precipitation, as one could expect, with average growing season temperature and temperature extremes playing a dominant role in predicting crop yields,” said Elisabeth Vogel of the University of Melbourne, who led the study.

Big picture reached

Nowhere was this more visible than in the figures for maize yield in Africa. “While Africa’s share of global maize production may be small, the largest part of that production goes to human consumption – compared to just 3% in North America – making it critical for food security in the region.”

Dr Vogel and her colleagues looked at crop yields, mean seasonal temperatures, extremes and regions to arrive at their big picture. But impacts of extremes vary according to region, soil, latitude and other factors too.

US scientists report in the journal Global Change Biology that yield statistics and crop insurance data from 1981 to 2016 on the Midwest maize harvest told them a slightly different story. In some years excessive rain reduced the corn yield by as much as 34%; drought and heat in turn could be linked to losses of 37%. It depended on where the crop was grown.

“As rainfall becomes more extreme, crop insurance needs to evolve to better meet planting challenges faced by farmers,” said Gary Schnitkey of the University of Urbana-Champaign, one of the authors.

Bananas in danger

And British scientists report in the Philosophical Transactions of the Royal Society B that changes in temperature and moisture linked to global warming could be bad for the banana crop.

These have increased the risk of infection by the fungus Pseudocercospora fijiensis, or Black Sigatoka disease, by more than 44% in Latin America and the Caribbean. The disease can reduce yield in infected plants by up to 80%.

“Climate change has made temperatures better for spore germination and growth, and made crop canopies wetter, raising the risk of Black Sigatoka infection in many banana-growing areas of Latin America,” said Daniel Bebber, of the University of Exeter.

“While fungus is likely to have been introduced to Honduras on plants imported from Asia for breeding research, our models indicate that climate change over the past 60 years has exacerbated its impact.” – Climate News Network

Arctic soils may produce huge methane leak

Arctic soils tell an ominous story. Change in the high latitudes could be swifter and more devastating than anyone had imagined.

LONDON, 9 May, 2019 − The permafrost may be about to spring an unwelcome surprise, with Arctic soils thought to be thawing faster than anyone had predicted. This threatens to release vast quantities of frozen methane into the atmosphere and transform the northern landscape.

One-fourth of all the land in the northern half of the globe is defined as permafrost. This long-frozen soil is home to the detritus of life over many thousands of years: the remains of plants, animals and microbes. The permanently frozen soils of the region hold, so far in a harmless state, 1,600 billion tonnes of carbon: twice as much as exists in the atmosphere.

And as the Arctic warms, this could release ever-greater volumes of a potent greenhouse gas, to accelerate global warming still further, and the consequent collapse of the soil, the flooding and the landslides could change not just the habitat but even the contours of the high latitudes.

“We are watching this sleeping giant wake up right in front of our eyes,” said Merritt Turetsky, an ecologist at the University of Guelph in Canada.

“Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north”

“We work in areas where permafrost contains a lot of ice, and our field sites are being destroyed by abrupt collapse of this ice, not gradually over decades, but very quickly over months to years.”

And Miriam Jones, of the US Geological Survey, said: “This abrupt thaw is changing forested ecosystems to thaw lakes and wetlands, resulting in a wholesale transformation of the landscape that not only impacts carbon feedbacks to climate but is also altering wildlife habitat and damaging infrastructure.”

The two scientists are among 14 researchers who argue in the journal Nature that the thaw is happening far faster than anyone had predicted. The Arctic is warming at a rate faster than almost anywhere else on Earth.

So far the thaw affects less than one-fifth of the entire permafrost, but even this relatively small area has the potential to double what climate scientists call “feedback” – the release of hitherto stored greenhouse gases to fuel yet faster warming.

Growing urgency

It is the latest in a series of increasingly urgent warnings about the rate of change in the Arctic.

Stable climate patterns are maintained by stable temperatures. As the polar north warms twice as fast as the average for the rest of the world, the all-important difference between tropics and polar regions begins to accelerate the advance of spring, and delay the next freeze to bring weather extremes and ever higher sea level rises which could soon start to exact a toll on human economies on an unprecedented scale.

Researchers have been warning for years about the consequences of thaw and the release of ever more carbon into the greenhouse atmosphere.

But it is only in recent months that climate scientists have begun to see the effect of ice melt at depth upon the soils that – for now – support Arctic roads, buildings and pipelines as well as a huge natural ecosystem of plants and animals adapted by thousands of years of evolution to long winters and brief flowering summers.

Goal in jeopardy

Put simply: 195 nations met in Paris in 2015 and agreed  to contain average global warming to “well below” 2°C above the long-term level for most of human history. Accelerating thaw in the Arctic puts that goal at risk.

The researchers call for better and more reliable observation of change in the region, more investment in on-the-ground measurement of change, more information about the extent of carbon emissions from the soils, better models of global change in the region, and better reporting of change.

“We can’t prevent abrupt thawing of the permafrost, but we can try to forecast where and when it is likely to happen, to enable decision makers and communities to protect people and resources”, the scientists write.

“Reducing global emissions might be the surest way to slow further release of permafrost carbon into the atmosphere. Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north.” − Climate News Network

Arctic soils tell an ominous story. Change in the high latitudes could be swifter and more devastating than anyone had imagined.

LONDON, 9 May, 2019 − The permafrost may be about to spring an unwelcome surprise, with Arctic soils thought to be thawing faster than anyone had predicted. This threatens to release vast quantities of frozen methane into the atmosphere and transform the northern landscape.

One-fourth of all the land in the northern half of the globe is defined as permafrost. This long-frozen soil is home to the detritus of life over many thousands of years: the remains of plants, animals and microbes. The permanently frozen soils of the region hold, so far in a harmless state, 1,600 billion tonnes of carbon: twice as much as exists in the atmosphere.

And as the Arctic warms, this could release ever-greater volumes of a potent greenhouse gas, to accelerate global warming still further, and the consequent collapse of the soil, the flooding and the landslides could change not just the habitat but even the contours of the high latitudes.

“We are watching this sleeping giant wake up right in front of our eyes,” said Merritt Turetsky, an ecologist at the University of Guelph in Canada.

“Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north”

“We work in areas where permafrost contains a lot of ice, and our field sites are being destroyed by abrupt collapse of this ice, not gradually over decades, but very quickly over months to years.”

And Miriam Jones, of the US Geological Survey, said: “This abrupt thaw is changing forested ecosystems to thaw lakes and wetlands, resulting in a wholesale transformation of the landscape that not only impacts carbon feedbacks to climate but is also altering wildlife habitat and damaging infrastructure.”

The two scientists are among 14 researchers who argue in the journal Nature that the thaw is happening far faster than anyone had predicted. The Arctic is warming at a rate faster than almost anywhere else on Earth.

So far the thaw affects less than one-fifth of the entire permafrost, but even this relatively small area has the potential to double what climate scientists call “feedback” – the release of hitherto stored greenhouse gases to fuel yet faster warming.

Growing urgency

It is the latest in a series of increasingly urgent warnings about the rate of change in the Arctic.

Stable climate patterns are maintained by stable temperatures. As the polar north warms twice as fast as the average for the rest of the world, the all-important difference between tropics and polar regions begins to accelerate the advance of spring, and delay the next freeze to bring weather extremes and ever higher sea level rises which could soon start to exact a toll on human economies on an unprecedented scale.

Researchers have been warning for years about the consequences of thaw and the release of ever more carbon into the greenhouse atmosphere.

But it is only in recent months that climate scientists have begun to see the effect of ice melt at depth upon the soils that – for now – support Arctic roads, buildings and pipelines as well as a huge natural ecosystem of plants and animals adapted by thousands of years of evolution to long winters and brief flowering summers.

Goal in jeopardy

Put simply: 195 nations met in Paris in 2015 and agreed  to contain average global warming to “well below” 2°C above the long-term level for most of human history. Accelerating thaw in the Arctic puts that goal at risk.

The researchers call for better and more reliable observation of change in the region, more investment in on-the-ground measurement of change, more information about the extent of carbon emissions from the soils, better models of global change in the region, and better reporting of change.

“We can’t prevent abrupt thawing of the permafrost, but we can try to forecast where and when it is likely to happen, to enable decision makers and communities to protect people and resources”, the scientists write.

“Reducing global emissions might be the surest way to slow further release of permafrost carbon into the atmosphere. Let’s keep that carbon where it belongs – safely frozen in the stunning soils of the north.” − Climate News Network

Heat makes ocean winds and waves fiercer

The seas are rising. Ocean winds and waves are growing in speed and force. The oceans could be feeling the heat.

LONDON, 1 May, 2019 − The great swells of the Pacific are beginning to swell even more as fiercer ocean winds and waves leave their mark. The breakers that crash on the storm beaches now do so with greater force. The white horses are gathering pace.

A 33-year-study of data from 31 satellites and 80 ocean buoys has confirmed suspicions. The extreme ocean winds are now fiercer, and the waves are getting measurably higher.

It is a given of global warming that as average planetary temperatures rise, then more energy is available for storm, rainfall and drought.

In the past century, because of ever-increasing combustion of fossil fuels that release growing quantities of greenhouse gases, average global temperatures have crept higher by 1°C and in three decades the speed of extreme winds in the Southern Ocean has increased by 8%, or 1.5 metres per second. Extreme waves have increased by 30cms, or 5%, over the same period.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk”

“Although increases of 5 and 8% might not seem like much, if sustained into the future such changes to our climate will have major impacts,” said Ian Young, an engineer at the University of Melbourne in Australia

He and a colleague report in the journal Science that they reached their conclusion on the basis of 4 billion observations made between 1985 and 2018.

“Flooding events are caused by storm surge and associated breaking waves. The increased sea level makes these events more serious and more frequent,” said Professor Young. “Increases in wave height, and changes in other properties such as wave direction, will further increase the probability of coastal flooding.”

Sea levels have been creeping ever higher, in large part because of the retreat of most of the planet’s great glaciers and the ever-increasing meltwater from Greenland and West Antarctica, and also as a simple matter of physics: as the oceans warm, the waters become less dense and sea levels rise.

Difficult measurements

Surfers and pleasure-seekers began to worry about the impact of global warming and climate change on wave patterns years ago. But seemingly simple phenomena such as the effects wave height and wind speed have in the open oceans on a world-wide basis are harder to measure.

Spanish oceanographers reported earlier this year that they were sure that ocean waves were gathering in force and strength, and European engineers have warned of the impact of more intense storms backed up by rising seas on the Atlantic ports and coastlines of the continent.

But there are problems: precision measurements have been made only recently. Oceanographers cannot be sure that they are not witnessing a natural cycle of ocean change, in which storm intensities slowly vary over a pattern of decades.

Since 1985 earth observation satellites have been equipped with altimeters to measure wave height and wind speed, radiometers to measure wind speed, and scatterometers to record wind speed and direction. The next problem has been calibrating data from a range of different satellites, and indeed the slightly different stories told by instruments on the same satellite.

Worse to come

But the Australian engineers report that they are now 90% confident that they can measure ocean change: violent storms now arrive with higher wave crests and more dangerous winds than they did in 1985, and although this is true worldwide, the effect is most pronounced in the great ocean that swirls around Antarctica.

The next challenge is to make estimates of how much more violent the worst sea storms are likely to become later in the century, as planetary average temperatures – and sea levels – continue to rise.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk,” Professor Young said.

“We need a better understanding of how much this change is due to long-term climate change, and how much is due to multi-decadal fluctuations or cycles.” − Climate News Network

The seas are rising. Ocean winds and waves are growing in speed and force. The oceans could be feeling the heat.

LONDON, 1 May, 2019 − The great swells of the Pacific are beginning to swell even more as fiercer ocean winds and waves leave their mark. The breakers that crash on the storm beaches now do so with greater force. The white horses are gathering pace.

A 33-year-study of data from 31 satellites and 80 ocean buoys has confirmed suspicions. The extreme ocean winds are now fiercer, and the waves are getting measurably higher.

It is a given of global warming that as average planetary temperatures rise, then more energy is available for storm, rainfall and drought.

In the past century, because of ever-increasing combustion of fossil fuels that release growing quantities of greenhouse gases, average global temperatures have crept higher by 1°C and in three decades the speed of extreme winds in the Southern Ocean has increased by 8%, or 1.5 metres per second. Extreme waves have increased by 30cms, or 5%, over the same period.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk”

“Although increases of 5 and 8% might not seem like much, if sustained into the future such changes to our climate will have major impacts,” said Ian Young, an engineer at the University of Melbourne in Australia

He and a colleague report in the journal Science that they reached their conclusion on the basis of 4 billion observations made between 1985 and 2018.

“Flooding events are caused by storm surge and associated breaking waves. The increased sea level makes these events more serious and more frequent,” said Professor Young. “Increases in wave height, and changes in other properties such as wave direction, will further increase the probability of coastal flooding.”

Sea levels have been creeping ever higher, in large part because of the retreat of most of the planet’s great glaciers and the ever-increasing meltwater from Greenland and West Antarctica, and also as a simple matter of physics: as the oceans warm, the waters become less dense and sea levels rise.

Difficult measurements

Surfers and pleasure-seekers began to worry about the impact of global warming and climate change on wave patterns years ago. But seemingly simple phenomena such as the effects wave height and wind speed have in the open oceans on a world-wide basis are harder to measure.

Spanish oceanographers reported earlier this year that they were sure that ocean waves were gathering in force and strength, and European engineers have warned of the impact of more intense storms backed up by rising seas on the Atlantic ports and coastlines of the continent.

But there are problems: precision measurements have been made only recently. Oceanographers cannot be sure that they are not witnessing a natural cycle of ocean change, in which storm intensities slowly vary over a pattern of decades.

Since 1985 earth observation satellites have been equipped with altimeters to measure wave height and wind speed, radiometers to measure wind speed, and scatterometers to record wind speed and direction. The next problem has been calibrating data from a range of different satellites, and indeed the slightly different stories told by instruments on the same satellite.

Worse to come

But the Australian engineers report that they are now 90% confident that they can measure ocean change: violent storms now arrive with higher wave crests and more dangerous winds than they did in 1985, and although this is true worldwide, the effect is most pronounced in the great ocean that swirls around Antarctica.

The next challenge is to make estimates of how much more violent the worst sea storms are likely to become later in the century, as planetary average temperatures – and sea levels – continue to rise.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk,” Professor Young said.

“We need a better understanding of how much this change is due to long-term climate change, and how much is due to multi-decadal fluctuations or cycles.” − Climate News Network