As part of their analysis, Hansen and colleagues created a set of graphs that help explain why perceptions of global temperatures vary, and are often wrong, from season to season and year to year. So for example, my Brooklyn heat wave had New Yorkers uttering “global warming!” as we lumbered through each furnace-blast of a day; while the winter’s unusually frigid temperatures had climate change naysayers smugly tossing out comments of “global warming? ha!”
By looking at data from a more global perspective makes clear that extrapolating global trends based on the experience of one or two regions can be misleading.
“Unfortunately, it is common for the public to take the most recent local seasonal temperature anomaly as indicative of long-term climate trends,” Hansen notes. “[We hope] these global temperature anomaly maps may help people understand that the temperature anomaly in one place in one season has limited relevance to global trends.”
So even if last winter’s chilly temperatures in much of the United States caused many of us to ponder why temperatures seemed to be plummeting if we’re really in the midst of global warming, a more global view (as seen in the graphs) shows that global warming trends had hardly abated. In fact, believe it or not: despite the cool temperatures in the United States, last winter was the second-warmest on record!
Meanwhile, the global seasonal temperatures for the spring of 2010 (March, April, and May) were the warmest on GISS’s record. Does that mean that 2010 is gearing up to be the warmest on record? Since the warmest year on GISS’s record (2005) experienced especially high temperatures during the last four calendar months of the year, the jury is still out on 2010. Stay tuned…if last week’s sizzling start to fall in California was any indication, we may have a “winner.”