Tag Archives: James Hansen

2C rise will be a disaster say leading scientists

FOR IMMEDIATE RELEASE Countries round the world have pledged to try and limit the average global temperature rise to 2C above pre industrial figures. That’s way too high and would threaten major dislocations for civilization say a group of prominent scientists. London, 3 December – Governments have set the wrong target to limit climate change. The goal at present – to limit global warming to a maximum of 2°C higher than the average for most of human history  – “would have consequences that can be described as disastrous”, say 18 scientists in a review paper in the journal PLOS One. With a 2°C increase, “sea level rise of several meters could be expected,” they say.  “Increased climate extremes, already apparent at 0.8°C warming, would be more severe. Coral reefs and associated species, already stressed with current conditions, would be decimated by increased acidification, temperature and sea level rise.

Hansen at helm

The paper’s lead author is James Hansen, now at Columbia University, New York, and the former NASA scientist who in 1988 put global warming on the world’s front pages by telling a US government committee that “It’s time to stop waffling so much and say the evidence is pretty strong that the greenhouse effect is here.” Hansen’s fellow authors include the economist Jeffrey Sachs of Columbia University and the biologist Camille Parmesan, of the University of Plymouth in the UK and the University of Texas at Austin, USA. Their argument is that humanity and nature – “the modern world as we know it” – is adapted to what scientists call the Holocene climate that has existed for more than 10,000 years – since the end of the Ice Age, the beginnings of agriculture and the first settlement of the cities. Warming of 1°C relative to 1880–1920 keeps global temperature close to the Holocene range, but warming of 2°C, could cause “major dislocations for civilization.”

Clear arguments

The scientists study, uncompromisingly entitled “Assessing ‘dangerous climate change’: required reduction of carbon emissions to protect young people, future generations and nature” differs from many such climate analyses because it sets out its argument with remarkable directness and clarity, and serves as a useful briefing document for anyone – politicians, journalists and lay audiences – anxious to better understand the machinery of climate, and the forces that seem to be about to dictate climate change. Its critics will point out that it is also remarkably short on the usual circumlocutions, caveats, disclaimers and equivocations that tend to characterise most scientific papers. Hansen and his co-authors are however quite open about the major areas of uncertainty: their implicit argument is that if the worst outcomes turn out to be true, the consequences for humankind could be catastrophic.

Feedback is critical

The scientists case is that most political debate addresses the questions of reducing greenhouse gas emissions, but does not and perhaps cannot factor in the all potentially dangerous unknowns – the slow feedbacks that will follow the thawing of the Arctic, the release of frozen reserves of methane and carbon dioxide in the permafrost, and the melting of polar ice into the oceans. They point out that 170 nations have agreed on the need to limit fossil fuel emissions to avoid dangerous human-made climate change. “However the stark reality is that global emissions have accelerated, and new efforts are underway to massively expand fossil fuel extractions by drilling to increasing ocean depths and into the Arctic, squeezing oil from tar sands and tar shale, hydro-fracking to expand extraction of natural gas, developing exploitation of methane hydrates and mining of coal via mountain-top removal and mechanised long wall-mining.”

Still time

The scientists argue that swift and drastic action to limit global greenhouse gas emissions and contain warming to around 1°C would have two useful consequences. One is that it would not be far from the climate variations experienced as normal during the last 10,000 years, and secondly that it would make it more likely that the biosphere, and the soil, would be able to sequester a substantial proportion of the carbon dioxide released by human industrial civilisation. Trees are, in essence, captive carbon dioxide. But the warmer the world becomes, the more likely it is that existing forests – the Amazon, for example – will start to release more CO2 than they absorb, making the planet progressively even warmer. Therefore the scientists make a case for limiting overall global carbon emissions to 500 gigatonnes rather than the 1,000 billion tonnes in the 2°C rise scenario. “Although there is merit in simply chronicling what is happening, there is still opportunity for humanity to exercise free will,” says Hansen. – Climate News Network  

FOR IMMEDIATE RELEASE Countries round the world have pledged to try and limit the average global temperature rise to 2C above pre industrial figures. That’s way too high and would threaten major dislocations for civilization say a group of prominent scientists. London, 3 December – Governments have set the wrong target to limit climate change. The goal at present – to limit global warming to a maximum of 2°C higher than the average for most of human history  – “would have consequences that can be described as disastrous”, say 18 scientists in a review paper in the journal PLOS One. With a 2°C increase, “sea level rise of several meters could be expected,” they say.  “Increased climate extremes, already apparent at 0.8°C warming, would be more severe. Coral reefs and associated species, already stressed with current conditions, would be decimated by increased acidification, temperature and sea level rise.

Hansen at helm

The paper’s lead author is James Hansen, now at Columbia University, New York, and the former NASA scientist who in 1988 put global warming on the world’s front pages by telling a US government committee that “It’s time to stop waffling so much and say the evidence is pretty strong that the greenhouse effect is here.” Hansen’s fellow authors include the economist Jeffrey Sachs of Columbia University and the biologist Camille Parmesan, of the University of Plymouth in the UK and the University of Texas at Austin, USA. Their argument is that humanity and nature – “the modern world as we know it” – is adapted to what scientists call the Holocene climate that has existed for more than 10,000 years – since the end of the Ice Age, the beginnings of agriculture and the first settlement of the cities. Warming of 1°C relative to 1880–1920 keeps global temperature close to the Holocene range, but warming of 2°C, could cause “major dislocations for civilization.”

Clear arguments

The scientists study, uncompromisingly entitled “Assessing ‘dangerous climate change’: required reduction of carbon emissions to protect young people, future generations and nature” differs from many such climate analyses because it sets out its argument with remarkable directness and clarity, and serves as a useful briefing document for anyone – politicians, journalists and lay audiences – anxious to better understand the machinery of climate, and the forces that seem to be about to dictate climate change. Its critics will point out that it is also remarkably short on the usual circumlocutions, caveats, disclaimers and equivocations that tend to characterise most scientific papers. Hansen and his co-authors are however quite open about the major areas of uncertainty: their implicit argument is that if the worst outcomes turn out to be true, the consequences for humankind could be catastrophic.

Feedback is critical

The scientists case is that most political debate addresses the questions of reducing greenhouse gas emissions, but does not and perhaps cannot factor in the all potentially dangerous unknowns – the slow feedbacks that will follow the thawing of the Arctic, the release of frozen reserves of methane and carbon dioxide in the permafrost, and the melting of polar ice into the oceans. They point out that 170 nations have agreed on the need to limit fossil fuel emissions to avoid dangerous human-made climate change. “However the stark reality is that global emissions have accelerated, and new efforts are underway to massively expand fossil fuel extractions by drilling to increasing ocean depths and into the Arctic, squeezing oil from tar sands and tar shale, hydro-fracking to expand extraction of natural gas, developing exploitation of methane hydrates and mining of coal via mountain-top removal and mechanised long wall-mining.”

Still time

The scientists argue that swift and drastic action to limit global greenhouse gas emissions and contain warming to around 1°C would have two useful consequences. One is that it would not be far from the climate variations experienced as normal during the last 10,000 years, and secondly that it would make it more likely that the biosphere, and the soil, would be able to sequester a substantial proportion of the carbon dioxide released by human industrial civilisation. Trees are, in essence, captive carbon dioxide. But the warmer the world becomes, the more likely it is that existing forests – the Amazon, for example – will start to release more CO2 than they absorb, making the planet progressively even warmer. Therefore the scientists make a case for limiting overall global carbon emissions to 500 gigatonnes rather than the 1,000 billion tonnes in the 2°C rise scenario. “Although there is merit in simply chronicling what is happening, there is still opportunity for humanity to exercise free will,” says Hansen. – Climate News Network  

We're in the danger zone says Hansen

EMBARGOED until 2301 GMT on Saturday 25 May
The first scientist to warn the US Congress of the threat of climate change retired earlier this year. But that has not stopped him continuing to try to alert the world to the dangers he sees ahead.

LONDON, 26 May – Professor James Hansen, often described as the world’s most prominent climate scientist, has also chosen to be one of its most controversial.

His view that the world has already passed a dangerous threshold for a safe future, because there is too much carbon dioxide in the atmosphere, has led him to step up attacks on politicians and the oil business.

He has been well known internationally since 1988, when he caused a sensation by being the first to warn the US Congress that climate change was a threat to his country and the planet.

Unlike many scientists who produce their results and then remain silent, Professor Hansen has always demanded action from successive US administrations. But his new calculations about the danger the planet faces have led him to more strident warnings.

Politicians who have been stung by his criticism have been attacking back. For example Joe Oliver, the Canadian natural resources minister, who is keen to export oil from Albertan tar sands via a new pipeline to the US, said Hansen was irresponsible to claim the project would mean it was “game over for the planet”.

Oliver said: “This is exaggerated rhetoric. It’s frankly nonsense. I don’t know why he said it, but he should be ashamed of having said it.”

But Hansen is a hard man to criticize, because of the quality of his science and his broad knowledge of climate change. His status comes from his 32-year tenure as the head of the NASA Goddard Institute for Space Studies in New York City. He retired earlier this year.

He is currently adjunct professor at the Department of Earth and Environmental Sciences at Columbia University and even at 72 is active in writing, speaking and campaigning about climate change.

Inexorable increase

 

The reason is his belief that the maximum safe level of atmospheric CO2 for the planet is 350 parts per million (ppm). This figure is much lower than many other scientists believe the atmosphere can stand before climate change gets out of control.

Some favour 400 ppm as the danger level, and others have settled for 450 ppm, a figure most politicians are happy with because it delays the need for action by them for a long time.

Professor Hansen’s anxiety is that we have already passed the 400 ppm figure and there is no sign of government action to do anything to curb a continuous rise to 450 ppm and beyond.

He says he once accepted that 450 ppm might be tenable, but that recent science has changed that. Speaking on YouTube to promote his book Storms of my Grandchildren, he said: “Now we look at the Earth’s history more carefully and have better data on how the Earth responded to changes in global temperature and changes in the atmospheric composition in the past … we see we have already passed into the dangerous range.”

If we continue with business as usual, Professor Hansen says, Arctic ice will be gone in summertime, disappearing mountain glaciers will mean the summer water supply to hundreds of millions of people will be lost within 50 years, and the sub-tropical regions will expand, making places like northern Australia and the southern and south-west US hard to live in.. – Climate News Network

EMBARGOED until 2301 GMT on Saturday 25 May
The first scientist to warn the US Congress of the threat of climate change retired earlier this year. But that has not stopped him continuing to try to alert the world to the dangers he sees ahead.

LONDON, 26 May – Professor James Hansen, often described as the world’s most prominent climate scientist, has also chosen to be one of its most controversial.

His view that the world has already passed a dangerous threshold for a safe future, because there is too much carbon dioxide in the atmosphere, has led him to step up attacks on politicians and the oil business.

He has been well known internationally since 1988, when he caused a sensation by being the first to warn the US Congress that climate change was a threat to his country and the planet.

Unlike many scientists who produce their results and then remain silent, Professor Hansen has always demanded action from successive US administrations. But his new calculations about the danger the planet faces have led him to more strident warnings.

Politicians who have been stung by his criticism have been attacking back. For example Joe Oliver, the Canadian natural resources minister, who is keen to export oil from Albertan tar sands via a new pipeline to the US, said Hansen was irresponsible to claim the project would mean it was “game over for the planet”.

Oliver said: “This is exaggerated rhetoric. It’s frankly nonsense. I don’t know why he said it, but he should be ashamed of having said it.”

But Hansen is a hard man to criticize, because of the quality of his science and his broad knowledge of climate change. His status comes from his 32-year tenure as the head of the NASA Goddard Institute for Space Studies in New York City. He retired earlier this year.

He is currently adjunct professor at the Department of Earth and Environmental Sciences at Columbia University and even at 72 is active in writing, speaking and campaigning about climate change.

Inexorable increase

 

The reason is his belief that the maximum safe level of atmospheric CO2 for the planet is 350 parts per million (ppm). This figure is much lower than many other scientists believe the atmosphere can stand before climate change gets out of control.

Some favour 400 ppm as the danger level, and others have settled for 450 ppm, a figure most politicians are happy with because it delays the need for action by them for a long time.

Professor Hansen’s anxiety is that we have already passed the 400 ppm figure and there is no sign of government action to do anything to curb a continuous rise to 450 ppm and beyond.

He says he once accepted that 450 ppm might be tenable, but that recent science has changed that. Speaking on YouTube to promote his book Storms of my Grandchildren, he said: “Now we look at the Earth’s history more carefully and have better data on how the Earth responded to changes in global temperature and changes in the atmospheric composition in the past … we see we have already passed into the dangerous range.”

If we continue with business as usual, Professor Hansen says, Arctic ice will be gone in summertime, disappearing mountain glaciers will mean the summer water supply to hundreds of millions of people will be lost within 50 years, and the sub-tropical regions will expand, making places like northern Australia and the southern and south-west US hard to live in.. – Climate News Network

We’re in the danger zone says Hansen

EMBARGOED until 2301 GMT on Saturday 25 May The first scientist to warn the US Congress of the threat of climate change retired earlier this year. But that has not stopped him continuing to try to alert the world to the dangers he sees ahead. LONDON, 26 May – Professor James Hansen, often described as the world’s most prominent climate scientist, has also chosen to be one of its most controversial. His view that the world has already passed a dangerous threshold for a safe future, because there is too much carbon dioxide in the atmosphere, has led him to step up attacks on politicians and the oil business. He has been well known internationally since 1988, when he caused a sensation by being the first to warn the US Congress that climate change was a threat to his country and the planet. Unlike many scientists who produce their results and then remain silent, Professor Hansen has always demanded action from successive US administrations. But his new calculations about the danger the planet faces have led him to more strident warnings. Politicians who have been stung by his criticism have been attacking back. For example Joe Oliver, the Canadian natural resources minister, who is keen to export oil from Albertan tar sands via a new pipeline to the US, said Hansen was irresponsible to claim the project would mean it was “game over for the planet”. Oliver said: “This is exaggerated rhetoric. It’s frankly nonsense. I don’t know why he said it, but he should be ashamed of having said it.” But Hansen is a hard man to criticize, because of the quality of his science and his broad knowledge of climate change. His status comes from his 32-year tenure as the head of the NASA Goddard Institute for Space Studies in New York City. He retired earlier this year. He is currently adjunct professor at the Department of Earth and Environmental Sciences at Columbia University and even at 72 is active in writing, speaking and campaigning about climate change.

Inexorable increase

  The reason is his belief that the maximum safe level of atmospheric CO2 for the planet is 350 parts per million (ppm). This figure is much lower than many other scientists believe the atmosphere can stand before climate change gets out of control. Some favour 400 ppm as the danger level, and others have settled for 450 ppm, a figure most politicians are happy with because it delays the need for action by them for a long time. Professor Hansen’s anxiety is that we have already passed the 400 ppm figure and there is no sign of government action to do anything to curb a continuous rise to 450 ppm and beyond. He says he once accepted that 450 ppm might be tenable, but that recent science has changed that. Speaking on YouTube to promote his book Storms of my Grandchildren, he said: “Now we look at the Earth’s history more carefully and have better data on how the Earth responded to changes in global temperature and changes in the atmospheric composition in the past … we see we have already passed into the dangerous range.” If we continue with business as usual, Professor Hansen says, Arctic ice will be gone in summertime, disappearing mountain glaciers will mean the summer water supply to hundreds of millions of people will be lost within 50 years, and the sub-tropical regions will expand, making places like northern Australia and the southern and south-west US hard to live in.. – Climate News Network

EMBARGOED until 2301 GMT on Saturday 25 May The first scientist to warn the US Congress of the threat of climate change retired earlier this year. But that has not stopped him continuing to try to alert the world to the dangers he sees ahead. LONDON, 26 May – Professor James Hansen, often described as the world’s most prominent climate scientist, has also chosen to be one of its most controversial. His view that the world has already passed a dangerous threshold for a safe future, because there is too much carbon dioxide in the atmosphere, has led him to step up attacks on politicians and the oil business. He has been well known internationally since 1988, when he caused a sensation by being the first to warn the US Congress that climate change was a threat to his country and the planet. Unlike many scientists who produce their results and then remain silent, Professor Hansen has always demanded action from successive US administrations. But his new calculations about the danger the planet faces have led him to more strident warnings. Politicians who have been stung by his criticism have been attacking back. For example Joe Oliver, the Canadian natural resources minister, who is keen to export oil from Albertan tar sands via a new pipeline to the US, said Hansen was irresponsible to claim the project would mean it was “game over for the planet”. Oliver said: “This is exaggerated rhetoric. It’s frankly nonsense. I don’t know why he said it, but he should be ashamed of having said it.” But Hansen is a hard man to criticize, because of the quality of his science and his broad knowledge of climate change. His status comes from his 32-year tenure as the head of the NASA Goddard Institute for Space Studies in New York City. He retired earlier this year. He is currently adjunct professor at the Department of Earth and Environmental Sciences at Columbia University and even at 72 is active in writing, speaking and campaigning about climate change.

Inexorable increase

  The reason is his belief that the maximum safe level of atmospheric CO2 for the planet is 350 parts per million (ppm). This figure is much lower than many other scientists believe the atmosphere can stand before climate change gets out of control. Some favour 400 ppm as the danger level, and others have settled for 450 ppm, a figure most politicians are happy with because it delays the need for action by them for a long time. Professor Hansen’s anxiety is that we have already passed the 400 ppm figure and there is no sign of government action to do anything to curb a continuous rise to 450 ppm and beyond. He says he once accepted that 450 ppm might be tenable, but that recent science has changed that. Speaking on YouTube to promote his book Storms of my Grandchildren, he said: “Now we look at the Earth’s history more carefully and have better data on how the Earth responded to changes in global temperature and changes in the atmospheric composition in the past … we see we have already passed into the dangerous range.” If we continue with business as usual, Professor Hansen says, Arctic ice will be gone in summertime, disappearing mountain glaciers will mean the summer water supply to hundreds of millions of people will be lost within 50 years, and the sub-tropical regions will expand, making places like northern Australia and the southern and south-west US hard to live in.. – Climate News Network