Tag Archives: Temperature rise

Antarctic warming speed-up alarms researchers

The world’s largest reservoir of snow and ice could be melting faster than ever. Two new studies highlight Antarctic warming.

LONDON, 4 March, 2021 − Antarctic warming is accelerating: at least one of the southern continent’s ice shelves has been melting faster than ever. The polar summer of 2019-20 set a new record for temperatures above freezing point over the George VI ice shelf off the Antarctic Peninsula.

The finding is ominous: the ice shelves form a natural buttress that slows the rate of glacier flow from the continental bedrock. The faster the glaciers flow into the sea, the higher the hazard of sea level rise.

And a second study confirms that this is already happening in West Antarctica: researchers looked at 25 years of satellite observation of 14 glaciers in the Getz sector to find that meltwater is flowing into the Amundsen Sea ever faster. Between 1994 and 2018, these glaciers lost 315 billion tonnes of ice, enough to raise global sea levels by almost 1mm.

Melting rates in Antarctica have been a source of alarm for years. The latest studies confirm the picture of continuing melt.

“The high rates of increased glacier speed − coupled with ice thinning − confirm the Getz basin is losing more ice than it gains through snowfall”

US scientists report in the journal The Cryosphere that they too used satellite observation − 41 years of it − to measure summer meltwater on the ice and in the near-surface snow of the northern part of the George VI ice shelf. They identified the most widespread melt and the greatest total of melt days of any season during the 2019-2020 summer.

Air temperatures were above freezing for up to 90 hours, allowing pools of meltwater to collect on the shelf. At its peak 23% of the region was covered with water: the equivalent, in glaciology’s favourite popular measure, of 250,000 Olympic swimming pools.

“When the temperature is above zero degrees Celsius, that limits refreezing and also leads to further melting,” said Alison Banwell, of the University of Colorado at Boulder, who led the study. “Water absorbs more radiation than snow and ice, and that leads to even more melting.”

Remote and untrodden

The Getz shelf is one of the biggest of a sector of the West Antarctic known as Marie Byrd Land. A new report in Nature Communications confirms that all 14 measured glaciers there have picked up speed and reach the ocean ever more swiftly.

Three of them have accelerated by more than 44%. And over the years the loss of ice has been the equivalent of 126 million Olympic swimming pools − all of it now adding to global sea level rise.

“The Getz region of Antarctica is so remote that humans have never set foot on most of this part of the continent,” said Heather Selley, of the University of Leeds, UK, first author. “Satellite radar altimetry records have shown substantial thinning of the ice sheet.

“However, the high rates of increased glacier speed − coupled with ice thinning − now confirm the Getz basin is in dynamic imbalance, meaning that it is losing more ice than it gains through snowfall.” − Climate News Network

The world’s largest reservoir of snow and ice could be melting faster than ever. Two new studies highlight Antarctic warming.

LONDON, 4 March, 2021 − Antarctic warming is accelerating: at least one of the southern continent’s ice shelves has been melting faster than ever. The polar summer of 2019-20 set a new record for temperatures above freezing point over the George VI ice shelf off the Antarctic Peninsula.

The finding is ominous: the ice shelves form a natural buttress that slows the rate of glacier flow from the continental bedrock. The faster the glaciers flow into the sea, the higher the hazard of sea level rise.

And a second study confirms that this is already happening in West Antarctica: researchers looked at 25 years of satellite observation of 14 glaciers in the Getz sector to find that meltwater is flowing into the Amundsen Sea ever faster. Between 1994 and 2018, these glaciers lost 315 billion tonnes of ice, enough to raise global sea levels by almost 1mm.

Melting rates in Antarctica have been a source of alarm for years. The latest studies confirm the picture of continuing melt.

“The high rates of increased glacier speed − coupled with ice thinning − confirm the Getz basin is losing more ice than it gains through snowfall”

US scientists report in the journal The Cryosphere that they too used satellite observation − 41 years of it − to measure summer meltwater on the ice and in the near-surface snow of the northern part of the George VI ice shelf. They identified the most widespread melt and the greatest total of melt days of any season during the 2019-2020 summer.

Air temperatures were above freezing for up to 90 hours, allowing pools of meltwater to collect on the shelf. At its peak 23% of the region was covered with water: the equivalent, in glaciology’s favourite popular measure, of 250,000 Olympic swimming pools.

“When the temperature is above zero degrees Celsius, that limits refreezing and also leads to further melting,” said Alison Banwell, of the University of Colorado at Boulder, who led the study. “Water absorbs more radiation than snow and ice, and that leads to even more melting.”

Remote and untrodden

The Getz shelf is one of the biggest of a sector of the West Antarctic known as Marie Byrd Land. A new report in Nature Communications confirms that all 14 measured glaciers there have picked up speed and reach the ocean ever more swiftly.

Three of them have accelerated by more than 44%. And over the years the loss of ice has been the equivalent of 126 million Olympic swimming pools − all of it now adding to global sea level rise.

“The Getz region of Antarctica is so remote that humans have never set foot on most of this part of the continent,” said Heather Selley, of the University of Leeds, UK, first author. “Satellite radar altimetry records have shown substantial thinning of the ice sheet.

“However, the high rates of increased glacier speed − coupled with ice thinning − now confirm the Getz basin is in dynamic imbalance, meaning that it is losing more ice than it gains through snowfall.” − Climate News Network

Alpine plants face risk from growing climate heat

Like many mountainous regions, the European Alps are warming fast. Alpine plants will suffer – and life below ground as well.

LONDON, 1 March, 2021 – The early melting of snow in the Alps is not just bad news for ardent skiers and for those who are dependent on the money they earn during the winter sports season: Alpine plants are in danger too.

Rising temperatures due to climate change are also having a negative impact deep below the surface of the ground.

New research by scientists at the University of Manchester in the UK demonstrates that warming in the area is threatening microbes which live in the Alpine soils.

The microbes play a critical role in supporting life forms above ground, recycling key nutrients upon which animals, plants – and humans – depend.

“More extreme advances in snowmelt timing are forecast for the end of the century”

The microbes also control the amount of carbon stored in the soil: if the cycle of microbial activity is disrupted, then more carbon is released into the atmosphere, resulting in further global warming.

Arthur Broadbent, lead author of a research paper in the ISME Journal,  says climate change is having an alarming impact on microbial communities in Alpine soils.

“Using a high-alpine experiment in the Austrian Alps, we discovered that spring snowmelt triggers an abrupt seasonal transition in soil microbial communities, which is closely linked to rapid shifts in carbon and nitrogen cycling”, he said.

During the winter, microbes in the Alpine soils depend on snow to act as an insulating blanket, allowing them to continue to work throughout the cold months.

Himalayan disaster

The researchers say that climate change in the Alps is taking place at double the rate of the global average. Separate research indicates that profound changes are happening in the Alps and in many other mountainous regions around the world.

In February a flash flood in Uttarakhand in northern India killed nearly 70 people, with 136 more missing and now presumed dead. Most scientists believe the warming climate was the cause of the glacier melt which triggered the disaster.

There are predictions that over the next 80 years more than 90% of glacier ice in the Alpine region will be lost due to ever-rising temperatures.

“Snowmelt is predicted to occur 50 to 130 days earlier in alpine regions due to climate change by the end of the century”, says Dr Broadbent.

Increased warming

“Using experimental manipulations, we demonstrated that earlier snowmelt, of even just 10 days, leads to an earlier seasonal transition in microbial communities and biogeochemical cycling.”

The research paper says that changes in the microbial cycle caused by snow melt will result in less carbon being retained in the soil and so have a negative impact on the growth and productivity of plants.

“This would negatively affect agricultural production and disrupt natural ecosystems. It will also alter annual carbon fluxes in these ecosystems with the potential to cause further climate warming.”

The authors conclude with a clear warning: “More extreme advances in snowmelt timing are forecast for the end of the century.” – Climate News Network

Like many mountainous regions, the European Alps are warming fast. Alpine plants will suffer – and life below ground as well.

LONDON, 1 March, 2021 – The early melting of snow in the Alps is not just bad news for ardent skiers and for those who are dependent on the money they earn during the winter sports season: Alpine plants are in danger too.

Rising temperatures due to climate change are also having a negative impact deep below the surface of the ground.

New research by scientists at the University of Manchester in the UK demonstrates that warming in the area is threatening microbes which live in the Alpine soils.

The microbes play a critical role in supporting life forms above ground, recycling key nutrients upon which animals, plants – and humans – depend.

“More extreme advances in snowmelt timing are forecast for the end of the century”

The microbes also control the amount of carbon stored in the soil: if the cycle of microbial activity is disrupted, then more carbon is released into the atmosphere, resulting in further global warming.

Arthur Broadbent, lead author of a research paper in the ISME Journal,  says climate change is having an alarming impact on microbial communities in Alpine soils.

“Using a high-alpine experiment in the Austrian Alps, we discovered that spring snowmelt triggers an abrupt seasonal transition in soil microbial communities, which is closely linked to rapid shifts in carbon and nitrogen cycling”, he said.

During the winter, microbes in the Alpine soils depend on snow to act as an insulating blanket, allowing them to continue to work throughout the cold months.

Himalayan disaster

The researchers say that climate change in the Alps is taking place at double the rate of the global average. Separate research indicates that profound changes are happening in the Alps and in many other mountainous regions around the world.

In February a flash flood in Uttarakhand in northern India killed nearly 70 people, with 136 more missing and now presumed dead. Most scientists believe the warming climate was the cause of the glacier melt which triggered the disaster.

There are predictions that over the next 80 years more than 90% of glacier ice in the Alpine region will be lost due to ever-rising temperatures.

“Snowmelt is predicted to occur 50 to 130 days earlier in alpine regions due to climate change by the end of the century”, says Dr Broadbent.

Increased warming

“Using experimental manipulations, we demonstrated that earlier snowmelt, of even just 10 days, leads to an earlier seasonal transition in microbial communities and biogeochemical cycling.”

The research paper says that changes in the microbial cycle caused by snow melt will result in less carbon being retained in the soil and so have a negative impact on the growth and productivity of plants.

“This would negatively affect agricultural production and disrupt natural ecosystems. It will also alter annual carbon fluxes in these ecosystems with the potential to cause further climate warming.”

The authors conclude with a clear warning: “More extreme advances in snowmelt timing are forecast for the end of the century.” – Climate News Network

Science warns world of ‘ghastly’ future ahead

Take all the dire warnings and assessments that scientists have made. Add them up. Their answer? A ghastly future ahead.

LONDON, 19 January, 2021 − Humankind faces what 17 scientists have called “a ghastly future” − a threat to the Earth’s living things “so great that it is difficult to grasp for even well-informed experts.”

The dangers they pinpoint are the destruction and loss of the world’s plants and animals on an unprecedented scale; the overwhelming growth of the human population and the demand upon the world’s resources; and finally, climate disruption driven by human environmental change and fossil fuel dependence.

“This dire situation places an extraordinary responsibility on scientists to speak out candidly and accurately when engaging with government, business and the public,” they write in the journal Frontiers in Conservation Science.

“We especially draw attention to the lack of appreciation of the enormous challenges to creating a sustainable future.”

The scientists from Australia, the US and Mexico warn that as many as a million species could soon disappear from the face of the Earth in what is widely recognised as the planet’s sixth mass extinction.

“The mainstream is having difficulty grasping the magnitude of this loss, despite the steady erosion of the fabric of human civilisation”

Because the planetary burden of humans has doubled in just 50 years and could reach 10 bn by 2050, the world faces a future of hunger, malnutrition, mass unemployment, a refugee crisis and ever more devastating pandemics.

And human-triggered climate change will mean more fires, more frequent and intense flooding, poorer water and air quality, and worsening human health.

The authors base their portrait of an already beleaguered planet on more than 150 scientific studies, many of them on the dangerous loss of biodiversity, triggered by the human-wrought changes to 70% of the planet’s land surface. With this loss goes the Earth’s ability to support complex life.

“But the mainstream is having difficulty grasping the magnitude of this loss, despite the steady erosion of the fabric of human civilisation,” said Corey Bradshaw of Flinders University in Australia, the lead author.

“The problem is compounded by ignorance and short-term self-interest, with the pursuit of wealth and political interests stymying the action that is crucial for survival.”

Familiar litany

Most of the world’s economies, the authors argue, are predicated on the political belief that meaningful counter-action would be too costly to be politically palatable. “Combined with financed disinformation campaigns in a bid to protect short-term profits, it is doubtful that any needed shift in economic investments of sufficient scale will be made in time.”

Importantly, the scientists who have signed the paper bring no new information: they simply attempt to put into perspective a series of findings that have been confirmed repeatedly.

Two-fifths of the world’s plant species are endangered; the collective mass of wild mammals worldwide has fallen by 25%; and 68% of vertebrate species have declined; much of this in the last century or so.

Humans and their domestic animals now add up to 95% of the mass of all vertebrates: the wild mammals, birds, reptiles and amphibians constitute just 5% of surviving creation.

And the structures that humans have fashioned − roads, buildings and so on − now outweigh the animals and plants on Earth.

With the loss of wilderness comes the loss of what researchers call natural capital and ecosystem services: the reduced pollination of crops, the degradation of soils, poorer air and water supplies, and so on.

Summons to act

In 1960, humans had already requisitioned around 73% of the planet’s regenerative capacity: that is, what humans demanded was still within the limits of the sustainable. In 2016, this demand had grown to an unsustainable 170%.

Around 700 to 800 million people are starving, and between one and two billion are malnourished. Population growth sparks both internal and international conflict and is in turn exacerbated by climate change driven by ever-higher global average temperatures.

The potential count of what researchers call environmental refugees − people driven from their homes by drought, poverty, civil war, flooding or heat extremes − has been set at anywhere between 25 million and 1bn by 2050.

And the scientists warn of political impotence: what nations and national leaders are doing to address any of these issues is ineffective in the face of what they call humanity’s “ecological Ponzi scheme in which society robs nature and future generations to pay for boosting incomes in the short term.”

They write: “Ours is not a call to surrender − we aim to provide leaders with a realistic ‘cold shower’ of the state of the planet that is essential for planning to avoid a ghastly future.” − Climate News Network

Take all the dire warnings and assessments that scientists have made. Add them up. Their answer? A ghastly future ahead.

LONDON, 19 January, 2021 − Humankind faces what 17 scientists have called “a ghastly future” − a threat to the Earth’s living things “so great that it is difficult to grasp for even well-informed experts.”

The dangers they pinpoint are the destruction and loss of the world’s plants and animals on an unprecedented scale; the overwhelming growth of the human population and the demand upon the world’s resources; and finally, climate disruption driven by human environmental change and fossil fuel dependence.

“This dire situation places an extraordinary responsibility on scientists to speak out candidly and accurately when engaging with government, business and the public,” they write in the journal Frontiers in Conservation Science.

“We especially draw attention to the lack of appreciation of the enormous challenges to creating a sustainable future.”

The scientists from Australia, the US and Mexico warn that as many as a million species could soon disappear from the face of the Earth in what is widely recognised as the planet’s sixth mass extinction.

“The mainstream is having difficulty grasping the magnitude of this loss, despite the steady erosion of the fabric of human civilisation”

Because the planetary burden of humans has doubled in just 50 years and could reach 10 bn by 2050, the world faces a future of hunger, malnutrition, mass unemployment, a refugee crisis and ever more devastating pandemics.

And human-triggered climate change will mean more fires, more frequent and intense flooding, poorer water and air quality, and worsening human health.

The authors base their portrait of an already beleaguered planet on more than 150 scientific studies, many of them on the dangerous loss of biodiversity, triggered by the human-wrought changes to 70% of the planet’s land surface. With this loss goes the Earth’s ability to support complex life.

“But the mainstream is having difficulty grasping the magnitude of this loss, despite the steady erosion of the fabric of human civilisation,” said Corey Bradshaw of Flinders University in Australia, the lead author.

“The problem is compounded by ignorance and short-term self-interest, with the pursuit of wealth and political interests stymying the action that is crucial for survival.”

Familiar litany

Most of the world’s economies, the authors argue, are predicated on the political belief that meaningful counter-action would be too costly to be politically palatable. “Combined with financed disinformation campaigns in a bid to protect short-term profits, it is doubtful that any needed shift in economic investments of sufficient scale will be made in time.”

Importantly, the scientists who have signed the paper bring no new information: they simply attempt to put into perspective a series of findings that have been confirmed repeatedly.

Two-fifths of the world’s plant species are endangered; the collective mass of wild mammals worldwide has fallen by 25%; and 68% of vertebrate species have declined; much of this in the last century or so.

Humans and their domestic animals now add up to 95% of the mass of all vertebrates: the wild mammals, birds, reptiles and amphibians constitute just 5% of surviving creation.

And the structures that humans have fashioned − roads, buildings and so on − now outweigh the animals and plants on Earth.

With the loss of wilderness comes the loss of what researchers call natural capital and ecosystem services: the reduced pollination of crops, the degradation of soils, poorer air and water supplies, and so on.

Summons to act

In 1960, humans had already requisitioned around 73% of the planet’s regenerative capacity: that is, what humans demanded was still within the limits of the sustainable. In 2016, this demand had grown to an unsustainable 170%.

Around 700 to 800 million people are starving, and between one and two billion are malnourished. Population growth sparks both internal and international conflict and is in turn exacerbated by climate change driven by ever-higher global average temperatures.

The potential count of what researchers call environmental refugees − people driven from their homes by drought, poverty, civil war, flooding or heat extremes − has been set at anywhere between 25 million and 1bn by 2050.

And the scientists warn of political impotence: what nations and national leaders are doing to address any of these issues is ineffective in the face of what they call humanity’s “ecological Ponzi scheme in which society robs nature and future generations to pay for boosting incomes in the short term.”

They write: “Ours is not a call to surrender − we aim to provide leaders with a realistic ‘cold shower’ of the state of the planet that is essential for planning to avoid a ghastly future.” − Climate News Network

Rising heat forces big growth in electricity demand

As temperatures increase, rising heat will mean many power stations falter, leaving homes dark, chilly and short of energy.

LONDON, 13 January, 2021 − US scientists have identified a new anxiety for a world of heat extremes. As the thermometer climbs, they warn, the efficiency of thermal power plants will fall, as the rising heat makes it harder to keep the generators cool.

In a world in which billions of urban dwellers could be exposed to temperatures at the moment experienced in the Sahara desert and other  hotspots, and in which heat and humidity could reach potentially lethal  levels, the problems ahead for energy companies may seem of less consequence.

But rising city temperatures will inevitably be matched by ever-greater demand for electrically-driven air conditioning. And as air and water temperatures rise, and demand increases, turbines driven by coal, oil and gas combustion must, to operate efficiently, be cooled by air or water.

But if the air and water are warmer too, efficiency and then capacity could fall, by as much as 10%, causing periods when power suddenly becomes unavailable.

“We are already feeling the impacts of global warming. Governments should be preparing for the large increases in electricity demand that will come with increased temperatures”

And on the latest calculations, in the journal Environmental Research Letters, if global average temperatures increase by 2°C, then the number of outages on hot days could double.

In fact, global average temperatures have already climbed by more than 1°C, and could hit 1.5°C as early as 2027. Demand for air conditioning has already begun to affect US energy supplies.

“Our work demonstrates a harmful interaction between human adaptation and infrastructure vulnerability in a warming world,” said Ethan Coffel, a geographer at Syracuse University in New York, who led the research into the likely impacts of rising heat.

“As hot days become more frequent, people will want air conditioners to protect themselves from unpleasant and dangerous heat. But these air conditioners need electricity, which further increases the greenhouse emissions that drive global warming further.”

Big shortfall

And that puts a strain on the grid that distributes power around a nation. It also sets a challenge to those nations that have yet to invest heavily in renewable energy sources such as wind power and photovoltaic cells, and to phase out thermal generators.

“By the middle of the century we find that 100 to 200 additional average-sized global power plants could be required to make up for the electricity generating capacity lost due to heat,” Dr Coffel warned.

“Major progress has been made to reduce the cost of wind and solar power − these zero-carbon sources are now often cheaper than fossil fuels. So making the transition away from coal, oil and gas not only makes climate sense, but also economic sense.

“However, we are already feeling the impacts of global warming. Governments should be preparing for the large increases in electricity demand that will come with increased temperatures.” − Climate News Network

As temperatures increase, rising heat will mean many power stations falter, leaving homes dark, chilly and short of energy.

LONDON, 13 January, 2021 − US scientists have identified a new anxiety for a world of heat extremes. As the thermometer climbs, they warn, the efficiency of thermal power plants will fall, as the rising heat makes it harder to keep the generators cool.

In a world in which billions of urban dwellers could be exposed to temperatures at the moment experienced in the Sahara desert and other  hotspots, and in which heat and humidity could reach potentially lethal  levels, the problems ahead for energy companies may seem of less consequence.

But rising city temperatures will inevitably be matched by ever-greater demand for electrically-driven air conditioning. And as air and water temperatures rise, and demand increases, turbines driven by coal, oil and gas combustion must, to operate efficiently, be cooled by air or water.

But if the air and water are warmer too, efficiency and then capacity could fall, by as much as 10%, causing periods when power suddenly becomes unavailable.

“We are already feeling the impacts of global warming. Governments should be preparing for the large increases in electricity demand that will come with increased temperatures”

And on the latest calculations, in the journal Environmental Research Letters, if global average temperatures increase by 2°C, then the number of outages on hot days could double.

In fact, global average temperatures have already climbed by more than 1°C, and could hit 1.5°C as early as 2027. Demand for air conditioning has already begun to affect US energy supplies.

“Our work demonstrates a harmful interaction between human adaptation and infrastructure vulnerability in a warming world,” said Ethan Coffel, a geographer at Syracuse University in New York, who led the research into the likely impacts of rising heat.

“As hot days become more frequent, people will want air conditioners to protect themselves from unpleasant and dangerous heat. But these air conditioners need electricity, which further increases the greenhouse emissions that drive global warming further.”

Big shortfall

And that puts a strain on the grid that distributes power around a nation. It also sets a challenge to those nations that have yet to invest heavily in renewable energy sources such as wind power and photovoltaic cells, and to phase out thermal generators.

“By the middle of the century we find that 100 to 200 additional average-sized global power plants could be required to make up for the electricity generating capacity lost due to heat,” Dr Coffel warned.

“Major progress has been made to reduce the cost of wind and solar power − these zero-carbon sources are now often cheaper than fossil fuels. So making the transition away from coal, oil and gas not only makes climate sense, but also economic sense.

“However, we are already feeling the impacts of global warming. Governments should be preparing for the large increases in electricity demand that will come with increased temperatures.” − Climate News Network

Earth is now committed to a 2°C hotter future

2020 matched all global heating records. In 2021 carbon releases will reach a milestone. Soon we face a 2°C hotter future.

LONDON, 12 January, 2021 − We Earthlings are now unmistakably on our way to the global climate we promised barely six years ago we’d never reach − a 2°C hotter future.

Some time this year, thanks to fossil fuel combustion and the destruction of natural ecosystems, the levels of carbon dioxide in the planetary atmosphere will be half as high again as the average for most of human history. That is, they will be more than half-way to doubling.

And the warming already driven by this extra charge of greenhouse gas has reached new heights: 2020, according to one calculation, shares with 2016 the grim accolade of the hottest year in history, at the end of the hottest decade since systematic records began.

A third study warns that yet more warming is now inevitable: the greenhouse gases already released must take average planetary temperatures from the present rise of more than 1°C to beyond 2°C − the limit that 195 nations vowed not to exceed when they met in Paris in 2015.

All three studies are simply progress reports on climate change itself. It is more than a century since scientists began to link carbon dioxide levels in the atmosphere with planetary temperatures, and more than 50 years since researchers began systematically monitoring atmospheric CO2 at an observatory in Hawaii, and since the first warnings that rising greenhouse gas levels could precipitate potentially catastrophic climate change.

“Our results suggest we have most likely already emitted enough carbon to exceed 2°C”

And this year, says the British Met Office, the ratio will creep up by more than 2 parts per million on last year. That will take the average to beyond 417 ppm for a number of weeks this northern hemisphere spring. And that will be 50% higher than the 278 ppm that was the norm at the close of the 18th century, when humans began to exploit coal, oil and gas as global sources of energy.

“The human-caused build-up of CO2 in the atmosphere is accelerating,” said Richard Betts, of the Met Office. “It took over 200 years for levels to increase by 25%, but now, just 30 years later, we are approaching a 50% increase.”

The last six years have all been in the hottest six years ever recorded, European scientists say in their calculations of the planetary pecking order of annual temperatures. It was 0.6°C warmer than the average for the years 1981-2010. And it is fully 1.25°C above the average for 1850 to 1900.

Europe in particular felt the heat: an average of 1.6° higher than the average for 1981 to 2010. And in the Arctic and in Siberia, temperatures were up to 6°C above the average for the same period.

“It is no surprise that the last decade was the warmest on record, and is yet another reminder of the urgency of ambitious emissions reductions to prevent adverse climate impacts in the future,” said Carlo Buontempo, who directs Europe’s Copernicus Climate Change Service.

Delay possible

Carbon dioxide is durable: it stays in the air, and each year’s emissions are added to those of the previous year. To keep the planet’s average temperature to a rise of no more than 1.5°C the ideal of the Paris Accord in 2015 − then nations must bring global emissions to zero within the next 30 years. In fact the limit of 2°C explicit in the Accord must now, and inevitably, be exceeded at some point: there is already enough greenhouse gas in the mix to guarantee that. The big question is: when.

Chinese and US researchers report in Nature Climate Change that they looked more closely at the pattern of changes in the planet’s surface temperatures, and the impact of low-level clouds that normally reflect heat back into space. And they see regions that have yet to warm, but must do so sooner or later to raise average global temperatures to levels so far not accounted for.

“The important thing to realise is that this has not happened − it is not in the historical record,” said Chen Zhou of Nanjing University, the lead author. “After accounting for this effect, the estimated future warming based on the historical record would be much higher than previous estimates.”

And his co-author Andrew Dessler, of Texas A&M University, said: “The bad news is that our results suggest we have most likely already emitted enough carbon to exceed 2C.”

But this could be delayed by urgent action. “If we can get emissions to net zero soon, it may take centuries to exceed 2°C.” − Climate News Network

2020 matched all global heating records. In 2021 carbon releases will reach a milestone. Soon we face a 2°C hotter future.

LONDON, 12 January, 2021 − We Earthlings are now unmistakably on our way to the global climate we promised barely six years ago we’d never reach − a 2°C hotter future.

Some time this year, thanks to fossil fuel combustion and the destruction of natural ecosystems, the levels of carbon dioxide in the planetary atmosphere will be half as high again as the average for most of human history. That is, they will be more than half-way to doubling.

And the warming already driven by this extra charge of greenhouse gas has reached new heights: 2020, according to one calculation, shares with 2016 the grim accolade of the hottest year in history, at the end of the hottest decade since systematic records began.

A third study warns that yet more warming is now inevitable: the greenhouse gases already released must take average planetary temperatures from the present rise of more than 1°C to beyond 2°C − the limit that 195 nations vowed not to exceed when they met in Paris in 2015.

All three studies are simply progress reports on climate change itself. It is more than a century since scientists began to link carbon dioxide levels in the atmosphere with planetary temperatures, and more than 50 years since researchers began systematically monitoring atmospheric CO2 at an observatory in Hawaii, and since the first warnings that rising greenhouse gas levels could precipitate potentially catastrophic climate change.

“Our results suggest we have most likely already emitted enough carbon to exceed 2°C”

And this year, says the British Met Office, the ratio will creep up by more than 2 parts per million on last year. That will take the average to beyond 417 ppm for a number of weeks this northern hemisphere spring. And that will be 50% higher than the 278 ppm that was the norm at the close of the 18th century, when humans began to exploit coal, oil and gas as global sources of energy.

“The human-caused build-up of CO2 in the atmosphere is accelerating,” said Richard Betts, of the Met Office. “It took over 200 years for levels to increase by 25%, but now, just 30 years later, we are approaching a 50% increase.”

The last six years have all been in the hottest six years ever recorded, European scientists say in their calculations of the planetary pecking order of annual temperatures. It was 0.6°C warmer than the average for the years 1981-2010. And it is fully 1.25°C above the average for 1850 to 1900.

Europe in particular felt the heat: an average of 1.6° higher than the average for 1981 to 2010. And in the Arctic and in Siberia, temperatures were up to 6°C above the average for the same period.

“It is no surprise that the last decade was the warmest on record, and is yet another reminder of the urgency of ambitious emissions reductions to prevent adverse climate impacts in the future,” said Carlo Buontempo, who directs Europe’s Copernicus Climate Change Service.

Delay possible

Carbon dioxide is durable: it stays in the air, and each year’s emissions are added to those of the previous year. To keep the planet’s average temperature to a rise of no more than 1.5°C the ideal of the Paris Accord in 2015 − then nations must bring global emissions to zero within the next 30 years. In fact the limit of 2°C explicit in the Accord must now, and inevitably, be exceeded at some point: there is already enough greenhouse gas in the mix to guarantee that. The big question is: when.

Chinese and US researchers report in Nature Climate Change that they looked more closely at the pattern of changes in the planet’s surface temperatures, and the impact of low-level clouds that normally reflect heat back into space. And they see regions that have yet to warm, but must do so sooner or later to raise average global temperatures to levels so far not accounted for.

“The important thing to realise is that this has not happened − it is not in the historical record,” said Chen Zhou of Nanjing University, the lead author. “After accounting for this effect, the estimated future warming based on the historical record would be much higher than previous estimates.”

And his co-author Andrew Dessler, of Texas A&M University, said: “The bad news is that our results suggest we have most likely already emitted enough carbon to exceed 2C.”

But this could be delayed by urgent action. “If we can get emissions to net zero soon, it may take centuries to exceed 2°C.” − Climate News Network

Dangerously hotter cities await 2100’s residents

In the concrete jungle, the most dramatic high-rise could be the mercury. Urban dwellers should expect much hotter cities.

LONDON, 8 January 2021 − Tomorrow’s metropolises will feel the heat: by the close of the century, assuming that nations act on vows to drastically reduce fossil fuel use, hotter cities − on average almost 2°C warmer than today − will be home to billions of people.

And if humans go on − as is the case now − tipping ever-greater levels of greenhouse gases into the atmosphere, then Paris and Philadelphia, Shanghai and São Paulo, Lagos and London, Beijing and Baghdad could see an average rise of 4.4°C.

The world’s cities are also likely to become less humid as the thermometer goes up, say US scientists who have harnessed machine-learning to statistical data to find a new way of checking the future of the planet’s cities this century.

Such research is literally vital, and vital to most of humankind. Right now, cities − concentrations of people, asphalt, concrete, brick, glass and steel − cover just 3% of the globe’s terrestrial surface, but shelter more than 50% of the world’s people. By 2050, the present megacities and many new ones will be home to more than 70% of humanity.

And they will become hot properties in every sense, simply because they are cities.

Global picture

“Cities are full of surfaces made from concrete and asphalt and retain more heat than natural surfaces and perturb other local-scale biophysical processes,” said Lei Zhao, an engineer at the University of Urbana-Champaign in the US.

“Incorporating these types of small-scale variables into climate modelling is crucial for understanding future urban climate. However, finding a way to include them in global-scale models poses major resolution, scale and computational challenges.”

Dr Zhao and his colleagues report in the journal Nature Climate Change that they combined a range of climate simulations with data-driven statistical models to bring a picture − on a global scale − of the overall average impact of climate change on the urban world.

The researchers stress that their results deliver only the big picture, are inevitably subject to uncertainties, and deliver average temperatures rather than extremes.

“Cities are full of surfaces made from concrete and asphalt and retain more heat than natural surfaces and perturb other local-scale biophysical processes”

But they offer a clear warning that, by 2100, the mid-to-northern US, southern Canada, Europe, the Middle East, northern Central Asia and north-western China will “exhibit the most pronounced urban warming during both daytime and night-time. Inland South America also shows strong night-time warming.”

High-latitude cities in the northern hemisphere will, they find, warm considerably during the winter months: Anchorage in Alaska is already experiencing climate change at twice the rate of cities at mid-latitudes.

They also find a near-universal decrease in relative humidity in cities during the summer months by the end of the century: in some cases, this will inevitably be translated into heat stress, water scarcity and energy uncertainty.

This broad-brush, big-picture forecast for things to come has already been prefigured in earlier research into the potential consequences of heat extremes.

Average increases of 1.9°C or 4.4°C sound alarming enough, but these mean, median or average figures mask a range of extremes likely to impose costs on urban economies, human health and even mortality.

Less stress

Heat extremes are on the way. Heat can kill. High temperatures combined with high humidity could make life without air-conditioning precarious. But air-conditioning heightens energy demand and at the same time makes the streets even hotter.

And researchers have already identified the most dangerous landscapes: the megacities, especially those in parts of China and south Asia. By 2070, as many as three billion people could at some time of the year face heat levels now considered extreme, and for now a challenge to only a few.

The helpful news from the study is that, as humidity levels fall in the cities, this will make surface evaporation more efficient as a cooling mechanism. If so, then what some researchers politely call “green infrastructure” could offer real help: city parks and green spaces could become urban forests. Trees in streets and gardens could help cool the ambient air.

“Our findings highlight the critical need for global projections of local urban climates for climate-sensitive urban areas,” Dr Zhao said. “This could give city planners the support they need to encourage solutions such as green infrastructure intervention to reduce urban heat stress on large scales.” − Climate News Network

In the concrete jungle, the most dramatic high-rise could be the mercury. Urban dwellers should expect much hotter cities.

LONDON, 8 January 2021 − Tomorrow’s metropolises will feel the heat: by the close of the century, assuming that nations act on vows to drastically reduce fossil fuel use, hotter cities − on average almost 2°C warmer than today − will be home to billions of people.

And if humans go on − as is the case now − tipping ever-greater levels of greenhouse gases into the atmosphere, then Paris and Philadelphia, Shanghai and São Paulo, Lagos and London, Beijing and Baghdad could see an average rise of 4.4°C.

The world’s cities are also likely to become less humid as the thermometer goes up, say US scientists who have harnessed machine-learning to statistical data to find a new way of checking the future of the planet’s cities this century.

Such research is literally vital, and vital to most of humankind. Right now, cities − concentrations of people, asphalt, concrete, brick, glass and steel − cover just 3% of the globe’s terrestrial surface, but shelter more than 50% of the world’s people. By 2050, the present megacities and many new ones will be home to more than 70% of humanity.

And they will become hot properties in every sense, simply because they are cities.

Global picture

“Cities are full of surfaces made from concrete and asphalt and retain more heat than natural surfaces and perturb other local-scale biophysical processes,” said Lei Zhao, an engineer at the University of Urbana-Champaign in the US.

“Incorporating these types of small-scale variables into climate modelling is crucial for understanding future urban climate. However, finding a way to include them in global-scale models poses major resolution, scale and computational challenges.”

Dr Zhao and his colleagues report in the journal Nature Climate Change that they combined a range of climate simulations with data-driven statistical models to bring a picture − on a global scale − of the overall average impact of climate change on the urban world.

The researchers stress that their results deliver only the big picture, are inevitably subject to uncertainties, and deliver average temperatures rather than extremes.

“Cities are full of surfaces made from concrete and asphalt and retain more heat than natural surfaces and perturb other local-scale biophysical processes”

But they offer a clear warning that, by 2100, the mid-to-northern US, southern Canada, Europe, the Middle East, northern Central Asia and north-western China will “exhibit the most pronounced urban warming during both daytime and night-time. Inland South America also shows strong night-time warming.”

High-latitude cities in the northern hemisphere will, they find, warm considerably during the winter months: Anchorage in Alaska is already experiencing climate change at twice the rate of cities at mid-latitudes.

They also find a near-universal decrease in relative humidity in cities during the summer months by the end of the century: in some cases, this will inevitably be translated into heat stress, water scarcity and energy uncertainty.

This broad-brush, big-picture forecast for things to come has already been prefigured in earlier research into the potential consequences of heat extremes.

Average increases of 1.9°C or 4.4°C sound alarming enough, but these mean, median or average figures mask a range of extremes likely to impose costs on urban economies, human health and even mortality.

Less stress

Heat extremes are on the way. Heat can kill. High temperatures combined with high humidity could make life without air-conditioning precarious. But air-conditioning heightens energy demand and at the same time makes the streets even hotter.

And researchers have already identified the most dangerous landscapes: the megacities, especially those in parts of China and south Asia. By 2070, as many as three billion people could at some time of the year face heat levels now considered extreme, and for now a challenge to only a few.

The helpful news from the study is that, as humidity levels fall in the cities, this will make surface evaporation more efficient as a cooling mechanism. If so, then what some researchers politely call “green infrastructure” could offer real help: city parks and green spaces could become urban forests. Trees in streets and gardens could help cool the ambient air.

“Our findings highlight the critical need for global projections of local urban climates for climate-sensitive urban areas,” Dr Zhao said. “This could give city planners the support they need to encourage solutions such as green infrastructure intervention to reduce urban heat stress on large scales.” − Climate News Network

More trees may do less to slow the climate crisis

In theory, more trees should mean a lower risk of dangerous climate change. In practice, it may not be so simple.

LONDON, 6 January, 2021 − The belief that more trees and better-protected forests can help contain climate change looks a little less sure − if only because climate change has already begun to affect the world’s trees and forests.

Researchers have in the last few weeks established a panoply of evidence that higher temperatures and more carbon dioxide may not be recipes for green growth in a greenhouse world.

In the tropics, as the thermometer rises, trees grow more vigorously − but overall lifespans are getting shorter. This must ultimately make the forests less efficient as absorbers of atmospheric carbon.

To compound the hazard to the rainforests, the proportion of the canopy that has always been fire-resistant is showing signs of decrease: in parts of Indonesia, only 10% of the forests remain fireproof.

Climate change and more importantly human disturbance continues to put the survival of whole groups of plants at risk: a new study finds that almost one-third of all the world’s 430 oak species are in danger of extinction.

A separate study of 447 North American trees suggests that they might not have what it takes to keep pace with changes in temperature and rainfall expected in a world of global heating.

Limited gains

And there is yet further evidence that more carbon dioxide does not inevitably mean more potential nourishment for plants: a study by the US space agency Nasa suggests that what scientists call the “carbon dioxide fertilisation effect” has been dwindling since 1982.

Finally, even the gains inevitable with rising temperatures in some regions could be limited. Another Nasa study finds that although Siberia, Canada and Alaska are becoming greener as the mercury rises, the increasing drought and tree death in the Amazon rainforest and others has offset this: another blow for those who hope more growth means more carbon absorption.

None of this should be a great surprise: the more researchers look in fine detail at the challenge of restoring natural habitat as part of the planetary arsenal against climate change, the more problems they have identified.

Although researchers have demonstrated that massive forest planting and restoration could in principle reduce the extra atmospheric carbon amassed over the last century, the details are less certain.

With more heat comes more drought which could turn some forests into sources of carbon rather than sinks. The increasing heat could affect the ability of some species to germinate, thus changing the makeup of the forests.

Trees may not only be dying younger, but growing shorter as conditions change.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C”

And although spring is occurring ever earlier, so is leaf fall: all these things reduce the efficiency of forests as greedy consumers of carbon.

So the latest harvest of research is simply further confirmation that the global heating to which the world is already committed is going to change the nature of those habitats that have − until now − kept the planet at an even temperature.

That means that restoring forests is not just a matter of planting trees: foresters will need to identify the right trees for climate regimes that have yet to be established.

Tropical rainforests cover only 7% of the planet’s land surface, but they shelter and nourish around half of all the planet’s plants and animal species. Around half of the Earth’s stocks of sequestered carbon are locked in the trunks, branches, leaves and roots.

Researchers report in the Proceedings of the National Academy of Sciences that they examined growth data from more than 100,000 trees of 438 different species found at 3,433 places around the world. They found that as temperatures go beyond 25°C, tree lifespans decline.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C,” said Emanuel Gloor, of the University of Leeds in the UK, one of the authors.

Human interference

“Our findings, which are the first to demonstrate that there is a temperature threshold, suggest that for trees in this region, their longevity is likely to be negatively affected.”

Rainforests maintain their own microclimates: they keep themselves humid, and therefore more or less fireproof, as long as they remain intact, even during a drought. Researchers report in Communications Earth & Environment that they found 90% of the natural forest cover of Sumatra and Kalimantan had been so badly degraded by human clearance and disturbance that it was no longer fire-resistant. What was true for Indonesia could probably be true too for Central Africa or the Amazon.

“Contrary to the widely-held perception that worsening droughts are threatening the remaining rainforests, tropical forests in Indonesia become susceptible to fire only after human disturbance,” said Tadas Nikonovas of Swansea University in Wales, who led the research.

Human disturbance of natural wilderness threatens not just forests as a whole, but individual species of trees, each of which can be a natural ecosystem, supporting other plants and animals. English oaks, for instance, provide food and shelter to more than 2,300 kinds of moss, fungus, lichen, bird, mammal and insect.

Researchers for the Morton Arboretum in Illinois in the US report that of the world’s 430 species of oak, 113 are threatened with extinction: these include 32 species in Mexico, 36 in China, 20 in Vietnam and 16 in the US.

Tropical trees have naturally faster life-cycles. Trees in cooler regions can on average survive for more than 300 years. Climate change however is likely to happen over a few decades. Can trees keep pace with change at that rate?

Plants need water

Researchers from the University of Maine report in the Journal of Biogeography that they think not. They looked at the climatic ranges most suitable for 447 North American trees and shrubs to find that overall, these were at only 48.6% of their full potential. That is, the trees are no longer in equilibrium with present climate, and must increasingly be at a disadvantage as climate change accelerates.

And although the main driver of global heating and thus climate change − ever-higher ratios of carbon dioxide in the atmosphere − confers some advantage on species that live by photosynthesis, this advantage may not be guaranteed. A space-based study in the journal Science found that over the last four decades, as CO2 ratios in the atmosphere rose, 86% of terrestrial ecosystems became progressively less efficient at absorbing the stuff.

That is, the world’s green canopies have slowed climate change, but their ability to go on doing so may be limited. That is because even though more carbon dioxide should mean more growth, unless there is more nitrogen and more soil moisture as well, a plant’s capacity to respond is limited.

And that, says a second study, in the journal AGU Advances, is less of a problem in some places than others. The Arctic is greening rapidly as average temperatures rise, and there is no shortage of moisture from the thawing permafrost, nor of partly decomposed plant material, to serve as nourishment.

A survey of growth from 1982 to 2016 found that carbon absorption increased in Canada, Alaska and Siberia. But global heating has begun to reduce soil moisture in the tropics, and the gains of the Arctic are not enough to offset losses in what had once been rainforest. Nor are the polar regions likely to go on getting ever-greener.

“I don’t expect that we have to wait another 35 years to see water limitations becoming a factor in the Arctic as well,” said one of the authors, Rolf Reichle, of the Goddard Space Flight Centre in Maryland in the US. − Climate News Network

In theory, more trees should mean a lower risk of dangerous climate change. In practice, it may not be so simple.

LONDON, 6 January, 2021 − The belief that more trees and better-protected forests can help contain climate change looks a little less sure − if only because climate change has already begun to affect the world’s trees and forests.

Researchers have in the last few weeks established a panoply of evidence that higher temperatures and more carbon dioxide may not be recipes for green growth in a greenhouse world.

In the tropics, as the thermometer rises, trees grow more vigorously − but overall lifespans are getting shorter. This must ultimately make the forests less efficient as absorbers of atmospheric carbon.

To compound the hazard to the rainforests, the proportion of the canopy that has always been fire-resistant is showing signs of decrease: in parts of Indonesia, only 10% of the forests remain fireproof.

Climate change and more importantly human disturbance continues to put the survival of whole groups of plants at risk: a new study finds that almost one-third of all the world’s 430 oak species are in danger of extinction.

A separate study of 447 North American trees suggests that they might not have what it takes to keep pace with changes in temperature and rainfall expected in a world of global heating.

Limited gains

And there is yet further evidence that more carbon dioxide does not inevitably mean more potential nourishment for plants: a study by the US space agency Nasa suggests that what scientists call the “carbon dioxide fertilisation effect” has been dwindling since 1982.

Finally, even the gains inevitable with rising temperatures in some regions could be limited. Another Nasa study finds that although Siberia, Canada and Alaska are becoming greener as the mercury rises, the increasing drought and tree death in the Amazon rainforest and others has offset this: another blow for those who hope more growth means more carbon absorption.

None of this should be a great surprise: the more researchers look in fine detail at the challenge of restoring natural habitat as part of the planetary arsenal against climate change, the more problems they have identified.

Although researchers have demonstrated that massive forest planting and restoration could in principle reduce the extra atmospheric carbon amassed over the last century, the details are less certain.

With more heat comes more drought which could turn some forests into sources of carbon rather than sinks. The increasing heat could affect the ability of some species to germinate, thus changing the makeup of the forests.

Trees may not only be dying younger, but growing shorter as conditions change.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C”

And although spring is occurring ever earlier, so is leaf fall: all these things reduce the efficiency of forests as greedy consumers of carbon.

So the latest harvest of research is simply further confirmation that the global heating to which the world is already committed is going to change the nature of those habitats that have − until now − kept the planet at an even temperature.

That means that restoring forests is not just a matter of planting trees: foresters will need to identify the right trees for climate regimes that have yet to be established.

Tropical rainforests cover only 7% of the planet’s land surface, but they shelter and nourish around half of all the planet’s plants and animal species. Around half of the Earth’s stocks of sequestered carbon are locked in the trunks, branches, leaves and roots.

Researchers report in the Proceedings of the National Academy of Sciences that they examined growth data from more than 100,000 trees of 438 different species found at 3,433 places around the world. They found that as temperatures go beyond 25°C, tree lifespans decline.

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25°C,” said Emanuel Gloor, of the University of Leeds in the UK, one of the authors.

Human interference

“Our findings, which are the first to demonstrate that there is a temperature threshold, suggest that for trees in this region, their longevity is likely to be negatively affected.”

Rainforests maintain their own microclimates: they keep themselves humid, and therefore more or less fireproof, as long as they remain intact, even during a drought. Researchers report in Communications Earth & Environment that they found 90% of the natural forest cover of Sumatra and Kalimantan had been so badly degraded by human clearance and disturbance that it was no longer fire-resistant. What was true for Indonesia could probably be true too for Central Africa or the Amazon.

“Contrary to the widely-held perception that worsening droughts are threatening the remaining rainforests, tropical forests in Indonesia become susceptible to fire only after human disturbance,” said Tadas Nikonovas of Swansea University in Wales, who led the research.

Human disturbance of natural wilderness threatens not just forests as a whole, but individual species of trees, each of which can be a natural ecosystem, supporting other plants and animals. English oaks, for instance, provide food and shelter to more than 2,300 kinds of moss, fungus, lichen, bird, mammal and insect.

Researchers for the Morton Arboretum in Illinois in the US report that of the world’s 430 species of oak, 113 are threatened with extinction: these include 32 species in Mexico, 36 in China, 20 in Vietnam and 16 in the US.

Tropical trees have naturally faster life-cycles. Trees in cooler regions can on average survive for more than 300 years. Climate change however is likely to happen over a few decades. Can trees keep pace with change at that rate?

Plants need water

Researchers from the University of Maine report in the Journal of Biogeography that they think not. They looked at the climatic ranges most suitable for 447 North American trees and shrubs to find that overall, these were at only 48.6% of their full potential. That is, the trees are no longer in equilibrium with present climate, and must increasingly be at a disadvantage as climate change accelerates.

And although the main driver of global heating and thus climate change − ever-higher ratios of carbon dioxide in the atmosphere − confers some advantage on species that live by photosynthesis, this advantage may not be guaranteed. A space-based study in the journal Science found that over the last four decades, as CO2 ratios in the atmosphere rose, 86% of terrestrial ecosystems became progressively less efficient at absorbing the stuff.

That is, the world’s green canopies have slowed climate change, but their ability to go on doing so may be limited. That is because even though more carbon dioxide should mean more growth, unless there is more nitrogen and more soil moisture as well, a plant’s capacity to respond is limited.

And that, says a second study, in the journal AGU Advances, is less of a problem in some places than others. The Arctic is greening rapidly as average temperatures rise, and there is no shortage of moisture from the thawing permafrost, nor of partly decomposed plant material, to serve as nourishment.

A survey of growth from 1982 to 2016 found that carbon absorption increased in Canada, Alaska and Siberia. But global heating has begun to reduce soil moisture in the tropics, and the gains of the Arctic are not enough to offset losses in what had once been rainforest. Nor are the polar regions likely to go on getting ever-greener.

“I don’t expect that we have to wait another 35 years to see water limitations becoming a factor in the Arctic as well,” said one of the authors, Rolf Reichle, of the Goddard Space Flight Centre in Maryland in the US. − Climate News Network

Seven years to ground zero for the climate crisis?

The Earth could cross an ominous temperature threshold in just seven years. A new study cuts the time for drastic action.

LONDON, 4 January, 2021 − Within the next seven years, the world could undergo irretrievable change. It could emit enough greenhouse gases from fossil fuel combustion to cross the threshold for dangerous global heating in the year 2027.

Or it could exceed what is supposed to be the globally-agreed target for containing catastrophic climate change − just 1.5°C above the average level for most of the last 10,000 years − a little later, in the year 2042.

But on present trends, according to new research, the world is committed, whatever happens, to the crossing of its own threshold for irreversible climate change within that 15-year window.

If that happens, then there is a high probability that some of the politicians and world leaders who, in Paris, in 2015, agreed an almost global accord to contain climate change to “well below” 2°C, will have to address their own failure to make it happen.

For the past forty or more years, campaigners, climate scientists and environmental researchers have repeatedly warned that inaction or sluggish responses to the increasingly ominous threat of climate change would present an increasingly urgent threat to the world, to be inherited by their children and grandchildren.

“With our new climate model and its next generation improvements, there’s less wiggle room”

And over the last decade or so, researchers have stressed the need for more urgent action: one study seven years ago predicted that some regions could be experiencing irreversible climate change by 2020.

Again and again, last year alone, scientists found that conditions initially proposed as the unlikely “worst case outcome” are already taking shape.

On the evidence of the latest study in the journal Climate Dynamics, however, they now have even less time in which to enforce dramatic cuts to fossil fuel use.

The new study is based on a new approach to climate simulation based on computer modelling, claimed by its authors to reduce the ranges of uncertainty that inevitably accompany all predictions of the future.

This uncertainty is a consequence of an as-yet unsolved riddle called climate sensitivity − climate science shorthand for a burning question: how much extra carbon dioxide has to build up in the atmosphere to raise global temperatures by a single degree, or half a degree Celsius?

Direct observations used

The climate models that underlie predictions by the Intergovernmental Panel on Climate Change assume that if the atmospheric ratios of carbon dioxide double − historically, these have been at around 285 parts per million, but have now passed 400 ppm − then the world is committed, by the year 2100, to a global temperature increase of at least 1.9°C, and possibly 4.5°C.

But three Canadian scientists suggest another way of modelling the near future: they based their simulation not on the theoretical relationships suggested by atmospheric physics but on historical climate data.

“Our approach allows climate sensitivity and its uncertainty to be estimated from direct observations with few assumptions,” said Raphaël Hébert, once of McGill University in Montreal and now at the Alfred-Wegener Institute in Potsdam, Germany.

And a co-author, Shaun Lovejoy of McGill University, warned: “Now that our governments have finally decided to act on climate change, we must avoid situations where leaders can claim that even the weakest policies can avert dangerous consequences.

“With our new climate model and its next generation improvements, there’s less wiggle room.” − Climate News Network

The Earth could cross an ominous temperature threshold in just seven years. A new study cuts the time for drastic action.

LONDON, 4 January, 2021 − Within the next seven years, the world could undergo irretrievable change. It could emit enough greenhouse gases from fossil fuel combustion to cross the threshold for dangerous global heating in the year 2027.

Or it could exceed what is supposed to be the globally-agreed target for containing catastrophic climate change − just 1.5°C above the average level for most of the last 10,000 years − a little later, in the year 2042.

But on present trends, according to new research, the world is committed, whatever happens, to the crossing of its own threshold for irreversible climate change within that 15-year window.

If that happens, then there is a high probability that some of the politicians and world leaders who, in Paris, in 2015, agreed an almost global accord to contain climate change to “well below” 2°C, will have to address their own failure to make it happen.

For the past forty or more years, campaigners, climate scientists and environmental researchers have repeatedly warned that inaction or sluggish responses to the increasingly ominous threat of climate change would present an increasingly urgent threat to the world, to be inherited by their children and grandchildren.

“With our new climate model and its next generation improvements, there’s less wiggle room”

And over the last decade or so, researchers have stressed the need for more urgent action: one study seven years ago predicted that some regions could be experiencing irreversible climate change by 2020.

Again and again, last year alone, scientists found that conditions initially proposed as the unlikely “worst case outcome” are already taking shape.

On the evidence of the latest study in the journal Climate Dynamics, however, they now have even less time in which to enforce dramatic cuts to fossil fuel use.

The new study is based on a new approach to climate simulation based on computer modelling, claimed by its authors to reduce the ranges of uncertainty that inevitably accompany all predictions of the future.

This uncertainty is a consequence of an as-yet unsolved riddle called climate sensitivity − climate science shorthand for a burning question: how much extra carbon dioxide has to build up in the atmosphere to raise global temperatures by a single degree, or half a degree Celsius?

Direct observations used

The climate models that underlie predictions by the Intergovernmental Panel on Climate Change assume that if the atmospheric ratios of carbon dioxide double − historically, these have been at around 285 parts per million, but have now passed 400 ppm − then the world is committed, by the year 2100, to a global temperature increase of at least 1.9°C, and possibly 4.5°C.

But three Canadian scientists suggest another way of modelling the near future: they based their simulation not on the theoretical relationships suggested by atmospheric physics but on historical climate data.

“Our approach allows climate sensitivity and its uncertainty to be estimated from direct observations with few assumptions,” said Raphaël Hébert, once of McGill University in Montreal and now at the Alfred-Wegener Institute in Potsdam, Germany.

And a co-author, Shaun Lovejoy of McGill University, warned: “Now that our governments have finally decided to act on climate change, we must avoid situations where leaders can claim that even the weakest policies can avert dangerous consequences.

“With our new climate model and its next generation improvements, there’s less wiggle room.” − Climate News Network

Rising heat means more methane, warmer nights

Nights are warmer. So are northern lakes. And farm livestock are at greater risk of disease, thanks to rising heat.

LONDON, 20 October, 2020 − Global warming has already begun to alter the world perceptibly, with rising heat changing daily life for millions of people.

Over more than half the planet’s land surface, nights are now warming at a rate faster than the days, with unpredictable consequences for plant and animal life.

Warmer winters now mean that in Europe, Asia and North America, lakes that would once have frozen over are now increasingly sometimes ice-free even at the darkest moments of the year.

And ever-higher temperatures encourage the spread of infectious diseases, and unexpectedly with that, the hazard of yet more warming.

Increasing parasitic activity among farm animals could mean that infected cattle, sheep and goats can produce up to a third more methane. This natural gas is around 30 times more potent, as a greenhouse gas, than the same volume of carbon dioxide.

“There is evidence that climate change, and warming temperatures in particular, are impacting some infectious diseases and increasing their prevalence”

The long-term consequences of any of these changes are difficult to foresee. British scientists report in the journal Global Change Biology that they searched the fine detail of global temperature, cloud cover, humidity and rainfall worldwide from 1983 to 2017 for any significant pattern of change, and found one.

Over more than half the terrestrial surface of the planet, there was a mean annual difference of at least 0.25°C between daytime and night-time warming.

In some places, days warmed more swiftly than nights. But disproportionately greater night-time warming happened over an area more than twice as large.

The agency at work appeared to be cloud cover: more clouds mean a cooler surface in daylight but a more effective blanket to retain warmth at night. Clear skies tend to mean hotter days and colder nights.

“We demonstrate that greater night-time warming is associated with climate becoming wetter, and this been shown to have important consequences for plant growth, and how species such as insects and mammals interact,” said Daniel Cox of Exeter University, UK, who led the research.

More ice-free lakes

“Conversely, we show that greater daytime warming is associated with drier conditions, combined with greater levels of overall warming, which increases vulnerability to heat stress and dehydration. Species that are only active at night or during the day will be particularly affected.”

Freezing winters play a vital role in the life of a northern lake. Canadian scientists report in the journal Geophysical Research Letters that they analysed almost eight decades of data − from 1939 to 2016 − for 122 lakes in Asia, Europe and America: the lakes included Baikal in Siberia, Geneva in Switzerland and Balaton in Hungary, Champlain and Michigan near the US- Canadian border, and Suwa in Japan, where records extend back to 1443.

They found that ice-free years have become three times more frequent since 1978, and 11% experienced at least one completely ice-free year since 1939. The trend was the same, everywhere they looked.

Lake ice is also vulnerable to rising heat. It is important to the winter recreation industry. It also plays a vital role in lake ecology. Without a sheath of winter ice, lakes stay warmer and stratify earlier to become more vulnerable to toxic algal blooms: this in turn is bad for fish, and for swimmers.

“Lake ice is becoming increasingly absent,” said Alessandro Filazzola of York University, Toronto, who led the study. “Even under low-carbon emissions scenarios, we’re going to have ice-free events.”

Methane’s rapid rise

Methane is a relatively short-lived but highly potent greenhouse gas: in the past decade it has increased rapidly in the atmosphere. About half of this increase comes from farm livestock.

US researchers report in the journal Trends in Ecology and Evolution that they looked at sheep studies to find that animals infected with intestinal worms produced up to 33% more methane per kilogram of food than uninfected animals. Dairy cows with mastitis − a bacterial infection − produce 8% more methane per litre of milk than uninfected animals.

Global livestock production could increase at the rate of 2.7% a year, according to UN forecasts. If so, between 2017 and 2050 methane production will soar by more than 20%. Throw parasitic worm infections into the forecasts and methane emissions from livestock could climb by up to 82% in the same period.

“There is evidence that climate change, and warming temperatures in particular, are impacting some infectious diseases and increasing their prevalence,” said Vanessa Ezenwa of the University of Georgia, first author.

“If that’s happening for livestock diseases, and simultaneously higher prevalence is triggering increased methane release, you could end up with what we call a vicious cycle.” − Climate News Network

Nights are warmer. So are northern lakes. And farm livestock are at greater risk of disease, thanks to rising heat.

LONDON, 20 October, 2020 − Global warming has already begun to alter the world perceptibly, with rising heat changing daily life for millions of people.

Over more than half the planet’s land surface, nights are now warming at a rate faster than the days, with unpredictable consequences for plant and animal life.

Warmer winters now mean that in Europe, Asia and North America, lakes that would once have frozen over are now increasingly sometimes ice-free even at the darkest moments of the year.

And ever-higher temperatures encourage the spread of infectious diseases, and unexpectedly with that, the hazard of yet more warming.

Increasing parasitic activity among farm animals could mean that infected cattle, sheep and goats can produce up to a third more methane. This natural gas is around 30 times more potent, as a greenhouse gas, than the same volume of carbon dioxide.

“There is evidence that climate change, and warming temperatures in particular, are impacting some infectious diseases and increasing their prevalence”

The long-term consequences of any of these changes are difficult to foresee. British scientists report in the journal Global Change Biology that they searched the fine detail of global temperature, cloud cover, humidity and rainfall worldwide from 1983 to 2017 for any significant pattern of change, and found one.

Over more than half the terrestrial surface of the planet, there was a mean annual difference of at least 0.25°C between daytime and night-time warming.

In some places, days warmed more swiftly than nights. But disproportionately greater night-time warming happened over an area more than twice as large.

The agency at work appeared to be cloud cover: more clouds mean a cooler surface in daylight but a more effective blanket to retain warmth at night. Clear skies tend to mean hotter days and colder nights.

“We demonstrate that greater night-time warming is associated with climate becoming wetter, and this been shown to have important consequences for plant growth, and how species such as insects and mammals interact,” said Daniel Cox of Exeter University, UK, who led the research.

More ice-free lakes

“Conversely, we show that greater daytime warming is associated with drier conditions, combined with greater levels of overall warming, which increases vulnerability to heat stress and dehydration. Species that are only active at night or during the day will be particularly affected.”

Freezing winters play a vital role in the life of a northern lake. Canadian scientists report in the journal Geophysical Research Letters that they analysed almost eight decades of data − from 1939 to 2016 − for 122 lakes in Asia, Europe and America: the lakes included Baikal in Siberia, Geneva in Switzerland and Balaton in Hungary, Champlain and Michigan near the US- Canadian border, and Suwa in Japan, where records extend back to 1443.

They found that ice-free years have become three times more frequent since 1978, and 11% experienced at least one completely ice-free year since 1939. The trend was the same, everywhere they looked.

Lake ice is also vulnerable to rising heat. It is important to the winter recreation industry. It also plays a vital role in lake ecology. Without a sheath of winter ice, lakes stay warmer and stratify earlier to become more vulnerable to toxic algal blooms: this in turn is bad for fish, and for swimmers.

“Lake ice is becoming increasingly absent,” said Alessandro Filazzola of York University, Toronto, who led the study. “Even under low-carbon emissions scenarios, we’re going to have ice-free events.”

Methane’s rapid rise

Methane is a relatively short-lived but highly potent greenhouse gas: in the past decade it has increased rapidly in the atmosphere. About half of this increase comes from farm livestock.

US researchers report in the journal Trends in Ecology and Evolution that they looked at sheep studies to find that animals infected with intestinal worms produced up to 33% more methane per kilogram of food than uninfected animals. Dairy cows with mastitis − a bacterial infection − produce 8% more methane per litre of milk than uninfected animals.

Global livestock production could increase at the rate of 2.7% a year, according to UN forecasts. If so, between 2017 and 2050 methane production will soar by more than 20%. Throw parasitic worm infections into the forecasts and methane emissions from livestock could climb by up to 82% in the same period.

“There is evidence that climate change, and warming temperatures in particular, are impacting some infectious diseases and increasing their prevalence,” said Vanessa Ezenwa of the University of Georgia, first author.

“If that’s happening for livestock diseases, and simultaneously higher prevalence is triggering increased methane release, you could end up with what we call a vicious cycle.” − Climate News Network

Laughing gas rise leaves climate science anxious

Atmospheric levels of laughing gas are on the increase, thanks to agriculture. This is no joke for climate change.

LONDON, 14 October, 2020 − If humans are to meet the global heating limits set by international agreement in 2015, they will have to think very hard about the effect of the supper table menu on laughing gas, more formally known as nitrous oxide.

That is because food production depends heavily on nitrogen fertilisers. But greenhouse gas emissions driven by agriculture are increasing atmospheric levels of nitrous oxide (N2O).

This is a greenhouse gas − popularly known as “laughing gas” − that is 300 times more potent than carbon dioxide, and it tends to stay in the atmosphere, driving up the thermometer, for at least 100 years. And in the 200 years since the start of the Industrial Revolution, atmospheric levels of nitrous oxide have risen by 20%, and are still rising.

Nitrous oxide is one of the six greenhouse gases identified in the Kyoto Protocol, the pioneering global climate agreement, as a danger whose emissions should be reduced by all its signatories.

The ratio of N2O to other gases is tiny, a thousand times lower than carbon dioxide, for instance, but an increase can still make a significant difference. In 1750 the ratio stood at 270 parts per billion. In 2018 it had reached 331 ppb, with the fastest growth all in the last 50 years, thanks to humankind’s demand for food.

“There is a conflict between the way we are feeding people and stabilising the climate”

And this, say 57 scientists from 14 nations in a report in the journal Nature, now threatens to eliminate any hope of containing global heating to “well below” 2°C by the year 2100. This is the target set in the Paris Agreement in 2015 by 195 nations.

Right now, the world has already warmed by 1°C in the last century and on all the evidence so far it is heading by the end of the century to be at least 3°C hotter than the average for most of the last 10,000 years of human history.

“The dominant driver of the increase in atmospheric nitrous oxide comes from agriculture, and the growing demand for food and feed for animals will further increase global nitrous oxide emissions,” said Hanqin Tian, of Auburn University’s School of Forestry and Wildlife Sciences in Alabama in the US. “There is a conflict between the way we are feeding people and stabilising the climate.”

He and his colleagues call their research an inventory of the traffic in nitrous oxide from human and from natural sources. The most significant human source is the fertiliser added to croplands.

They found that the highest growth in nitrous oxide emissions came from emerging economies in East Asia, South Asia, Africa and South America, from synthetic fertilisers and from livestock manure. In the course of the next few decades global population will soar, and so will the demand for food.

Total rethink

Researchers have consistently argued for a new approach to agriculture,  with ever-greater emphasis on plant-based diets, as a way to help contain climate change on a scale that is likely to actually threaten global food security.

“Europe is the only region in the world that has successfully reduced nitrous oxide emissions over the past two decades,” said Robert Jackson,  of Stanford University in the US, who chairs the Global Carbon Project.

“Industrial and agricultural policies to reduce greenhouse gases and air pollution and to optimise fertiliser use efficiencies have proven to be effective. Still, further efforts are required, in Europe as well as globally.”

And another author, Josep Canadell of Australia’s Commonwealth Scientific and Industrial Research Organisation, said: “This new analysis calls for a full rethink in the ways we use and abuse nitrogen fertilisers globally and urges us to adopt more sustainable practices in the way we produce food,  including the reduction of food waste.” − Climate News Network

Atmospheric levels of laughing gas are on the increase, thanks to agriculture. This is no joke for climate change.

LONDON, 14 October, 2020 − If humans are to meet the global heating limits set by international agreement in 2015, they will have to think very hard about the effect of the supper table menu on laughing gas, more formally known as nitrous oxide.

That is because food production depends heavily on nitrogen fertilisers. But greenhouse gas emissions driven by agriculture are increasing atmospheric levels of nitrous oxide (N2O).

This is a greenhouse gas − popularly known as “laughing gas” − that is 300 times more potent than carbon dioxide, and it tends to stay in the atmosphere, driving up the thermometer, for at least 100 years. And in the 200 years since the start of the Industrial Revolution, atmospheric levels of nitrous oxide have risen by 20%, and are still rising.

Nitrous oxide is one of the six greenhouse gases identified in the Kyoto Protocol, the pioneering global climate agreement, as a danger whose emissions should be reduced by all its signatories.

The ratio of N2O to other gases is tiny, a thousand times lower than carbon dioxide, for instance, but an increase can still make a significant difference. In 1750 the ratio stood at 270 parts per billion. In 2018 it had reached 331 ppb, with the fastest growth all in the last 50 years, thanks to humankind’s demand for food.

“There is a conflict between the way we are feeding people and stabilising the climate”

And this, say 57 scientists from 14 nations in a report in the journal Nature, now threatens to eliminate any hope of containing global heating to “well below” 2°C by the year 2100. This is the target set in the Paris Agreement in 2015 by 195 nations.

Right now, the world has already warmed by 1°C in the last century and on all the evidence so far it is heading by the end of the century to be at least 3°C hotter than the average for most of the last 10,000 years of human history.

“The dominant driver of the increase in atmospheric nitrous oxide comes from agriculture, and the growing demand for food and feed for animals will further increase global nitrous oxide emissions,” said Hanqin Tian, of Auburn University’s School of Forestry and Wildlife Sciences in Alabama in the US. “There is a conflict between the way we are feeding people and stabilising the climate.”

He and his colleagues call their research an inventory of the traffic in nitrous oxide from human and from natural sources. The most significant human source is the fertiliser added to croplands.

They found that the highest growth in nitrous oxide emissions came from emerging economies in East Asia, South Asia, Africa and South America, from synthetic fertilisers and from livestock manure. In the course of the next few decades global population will soar, and so will the demand for food.

Total rethink

Researchers have consistently argued for a new approach to agriculture,  with ever-greater emphasis on plant-based diets, as a way to help contain climate change on a scale that is likely to actually threaten global food security.

“Europe is the only region in the world that has successfully reduced nitrous oxide emissions over the past two decades,” said Robert Jackson,  of Stanford University in the US, who chairs the Global Carbon Project.

“Industrial and agricultural policies to reduce greenhouse gases and air pollution and to optimise fertiliser use efficiencies have proven to be effective. Still, further efforts are required, in Europe as well as globally.”

And another author, Josep Canadell of Australia’s Commonwealth Scientific and Industrial Research Organisation, said: “This new analysis calls for a full rethink in the ways we use and abuse nitrogen fertilisers globally and urges us to adopt more sustainable practices in the way we produce food,  including the reduction of food waste.” − Climate News Network