20 September 2011
NASA-GISS has put up the numbers for August, and the global land and ocean temperatures in August were the 4th warmest on record. NOAA has August pegged at the 8th warmest using a slightly different methodology. Land temperatures in August were the second warmest on record according to the NOAA-NCDC data.
The summer Arctic sea ice melt has ended, and NSIDC says the minimum sea ice was the second lowest on record (while the Univ. of Bremen puts it at an all time low). No matter how you measure it, there is little doubt that once again the amount of sea ice is running at levels near the all time low in the satellite record. The trend in summer ice is what really matters, not whether or not there was a record this year, and NSIDC data (showing the trend in July and August) is very interesting. The image to the right here is from a guest post on Real Climate that is worth reading.
Estimating the volume of the ice is a more difficult calculation, but every attempt made seems to show the loss of volume is much greater than that of the area or extent. There’s a new paper in BAMS (Bulletin of the AMS) about the Arctic ice that is number one on my reading list, and a summary of it is forthcoming soon. For now, the most likely question to ask is this: Just how will the growing drop in ice cover affect weather patterns??
No one really knows the definitive answer to that (except to say that it will and already is).