Although there seems to be almost universal agreement amongst scientists that we must be concerned about the effects of climate change on our planet, what hasn't been so clear has been how close we are getting to a danger-zone. A Paper to appear in the next days will, evidently, tell us that it is much closer than we might imagine.
"How much does the climate have to change for it to be “dangerous”? This question has vexed scientists ever since the first climate models were developed, back in the nineteen-seventies. It was provisionally answered in 2009, though by politicians rather than scientists. According to an agreement known as the Copenhagen Accord, which was brokered by President Barack Obama, to avoid danger, the world needs “to hold the increase in global temperature below 2 degrees Celsius” (3.6 degrees Fahrenheit).
Now a group of climate modellers is arguing that the danger point is, in fact, a lot lower than that. In a paper set to appear online this week in Atmospheric Chemistry and Physics, the modellers, led by James Hansen, the former director of NASA’s Goddard Institute for Space Studies, warn that an increase of two degrees Celsius could still be enough to melt large portions of Antarctica, which, in turn, could result in several metres’ worth of sea-level rise in a matter of decades. What’s important about the paper from a layperson’s perspective—besides the fate of the world’s major coastal cities, many of which would be swamped if the oceans rose that high—is that it shows just how far from resolved, scientifically speaking, the question of danger levels remains. And this has important political implications, though it seems doubtful that politicians will heed them.
To understand the significance of the new paper, it helps to go back to a pair of earlier papers on Antarctic melt, which appeared last year. In those papers, two teams of scientists independently reached the same conclusion: the disintegration of a major portion of the West Antarctic Ice Sheet is probably already under way. “Early stage collapse has begun,” one of the teams wrote in the journal Science. The leader of the other team seconded that view, saying, “The collapse of this sector of West Antarctica appears unstoppable.”
Continue reading this piece, from The New Yorker, here.
"How much does the climate have to change for it to be “dangerous”? This question has vexed scientists ever since the first climate models were developed, back in the nineteen-seventies. It was provisionally answered in 2009, though by politicians rather than scientists. According to an agreement known as the Copenhagen Accord, which was brokered by President Barack Obama, to avoid danger, the world needs “to hold the increase in global temperature below 2 degrees Celsius” (3.6 degrees Fahrenheit).
Now a group of climate modellers is arguing that the danger point is, in fact, a lot lower than that. In a paper set to appear online this week in Atmospheric Chemistry and Physics, the modellers, led by James Hansen, the former director of NASA’s Goddard Institute for Space Studies, warn that an increase of two degrees Celsius could still be enough to melt large portions of Antarctica, which, in turn, could result in several metres’ worth of sea-level rise in a matter of decades. What’s important about the paper from a layperson’s perspective—besides the fate of the world’s major coastal cities, many of which would be swamped if the oceans rose that high—is that it shows just how far from resolved, scientifically speaking, the question of danger levels remains. And this has important political implications, though it seems doubtful that politicians will heed them.
To understand the significance of the new paper, it helps to go back to a pair of earlier papers on Antarctic melt, which appeared last year. In those papers, two teams of scientists independently reached the same conclusion: the disintegration of a major portion of the West Antarctic Ice Sheet is probably already under way. “Early stage collapse has begun,” one of the teams wrote in the journal Science. The leader of the other team seconded that view, saying, “The collapse of this sector of West Antarctica appears unstoppable.”
Continue reading this piece, from The New Yorker, here.
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