One of the arguments commonly invoked against global warming “alarmism” is that the models have a significant degree of uncertainty.
But that uncertainty cuts both ways.
Evidence of ice loss from both poles this week has sparked fresh fears that global warming is progressing faster than scientists had predicted.
Arctic ice has thinned dramatically, as well as shrinking in area, according to US research. Thin seasonal ice, which melts and refreezes each year, now makes up about 70 per cent of the Arctic winter ice, up from about 40 to 50 per cent in the 1980s and 1990s, leaving far less of the older, thicker ice that is harder to melt.
In the Antarctic, an ice bridge connecting an island to the Wilkins ice shelf – a sheet of ice about the size of Northern Ireland – shattered as scientists monitored it through satellite observations.
“What we’re seeing is very dramatic,” said Andrew Fleming, remote sensing manager at the British Antarctic Survey. “It’s very worrying.”
Scientists believed the effects were linked to the “very strong warming” at the poles, he said. The Antarctic peninsula has warmed by more than 3ºC in the past 50 years. “That’s a staggering rate of warming, and it’s still going up,” said Mr Fleming. …
via Brad DeLong