Friday, January 21, 2011

2010: Warmest/Equal Warmest and Wettest year on record

Some of us may have been more preoccupied with flooding but several of the groups of scientists who take the earth's temperature have now reported back on 2010.

NASA reports that 2010 was the warmest year on record (going back to 1880), but so close in temperature to the next warmest year (2005) that the two are in a tie due to the margin of error in their measurements. The NASA graph below shows the steady warming of the climate since the 1970's.

NOAA, (essentially the American equivalent of the BOM) also find 2010 to be tied with 2005 for the warmest year of record. NOAA do more than just temperature though and also reported the interesting finding that 2010 was the wettest year on record globally, which is at least partially attributable to the El Nino and La Nina conditions experienced in 2010.

Both satellite datasets measuring the temperature of the lower atmosphere (which are separate to the surface temperature above) showed 2010 as the 2nd warmest year behind 1998, although again the difference was within the margin or error.
Why do the satellite datasets, but not the surface datasets above show 1998 as being part of the record hottest? I believe this is due to the lower atmosphere being more sensitive to the short term warming effects of El Nino and cooling effects of La Nina. 2010 was mostly dominated by an moderate to strong El Nino, 1998 had a record strong El Nino, whereas the 2005 El Nino was weaker. Given this, it is no surprise 1998 is more prominent in the satellite data. The fact that 2010 essentially tied with 1998 despite a considerably weaker El Nino hints at the growing warming influence of greenhouse gasses.
Overall, despite a bit of jostling for top spot between individual years, the different datasets agree very well and show similar long term warming trends.

And for the future? This prediction is from the head of the NASA group measuring the earth's temperature:
"If the warming trend continues, as is expected, if greenhouse gases continue to increase, the 2010 record will not stand for long," said James Hansen, the director of GISS.

No comments:

Post a Comment