You may have seen portions of this interview with Senior Climate Scientist Mike MacCracken in this fall’s Sea Ice Minimum video, and you may remember him for his classic and agonizingly spot-on 1982 lecture at Sandia Lab, which I covered here.
I interviewed Mike this past August in San Francisco. This is the complete 13 and a half minutes, and worth listening to.
Just read somewhere on SKS that MacDougall, Avis, et al are now saying that evoked methane from the melting permafrost may become a self sustaining greenhouse gas process. Possible tipping point crossed?
I’m sure there will be more on that at AGU in december. will report back.
I just stumbled across this on YouTube: http://www.youtube.com/watch?v=xwpnmsLwinI&
Just who is this professorial-looking chap?
A long way from the unwashed hippie we thought we knew.
I clean up well.
At 12:00, pointing to an area of multi-year ice in the arctic, Peter says:
“But this is all that’s left of the ice that is making it through more than one year. So we’re at a point where given the right conditions, this ice is so thin that the right combination of wind and sun and temperature could, almost in any given year going forward, cause that ice to open up completely during a given summer. So we’re very close to kind of a tipping point with that ice and it’s just kind of a matter of opinion whether it’s five, or ten or twenty years before we start seeing open water.”
In a different sense, using ice extent as the metric, a tipping point was passed in 2001. NSIDC average extent for September that year was 6.75 million square km. Every year after 2001 has had a lower September average than every year before 2001.