Claim: There can't be Global Warming. We had record low temperatures here in 2009

Why this Claim is Wrong: Basically, it's the difference between weather (short term variances due to moving cold and warm fronts), and climate (the average of weather over time scales of decades, so that daily and seasonal effects average away, revealing slower secular changes. Imagine getting down on your belly and examing a mountain stream from 2 inches away, and trying to predict what it would look like 2 seconds later. You'd find the task of making the prediction very tough at these tiny scales where mathematical chaos is important. But now stand on the high cliff over that same stream and try and predict what it'll look like in 2 hours. Much easier; it'll be nearly the same. And in 5 weeks? Maybe a little less water flow as summer continues. It's pretty obvious, really.

Also, as climate models predict and observations show, air temperatures are rising much faster in the Arctic than in the mid latitudes, and the resulting drop in temperature gradient between mid latitudes and the Arctic causes the Polar Jet Stream (which guides cold storm systems) to go through more dramatic north/south bends, bringing cold polar air further south than typical in some places (and warm air farther north than typical).

So when you hear AGW denialists claiming the cold winter of '09 disproves global warming, it's nonsense . As of 2011, 2010 was the hottest year on record.

In Short: It's cherry picking. 2008 was a La Nina year, with cool surface waters on the equatorial Pacific. Global warming can only be assessed with a time base that averages over the short-term weather year-to-year. It must span at least a couple of solar cycles and El Nino cycles. Arguing from a single year is naive. Also, we expect, and see, more severe weather due to warming poles modifying the path of the Polar Jet Stream.


Return to Climate Denial Claims List

Return to Climate Science Main Page