It won't be news to most of my readership, but it is worth noting that the one thing that seems to be certain about climate change is that the 2007 IPCC report understated things. Sigh.
That's in line with what I saw 2000 - 2003 on the U.S. Coast Guard Icebreaker HEALY. In 2000 there was a one mile diameter polynya at the North Pole. In 2001 with a continuous icebreaking capability of 5 feet ice thickness we got to the Pole unassisted on 05 September. Scientists on the ship who have been going to the Arctic every year since graduate school in the International Geophysical year in 1958 told me they have seen steady reduction of sea ice since then.
I wrote about the underestimation bias back then, 2007: tinyurl.com/43754wg
It's still something the climate community has not dealt with; but I think provably, mathematically, one can show that the top to bottom scientific process as currently used in the climate area WILL, reliably, produce underestimates of changes.
We need a statistician to point it out, I guess.
Man. it doesn't stop. Some seriously bad scary ice news today;