Is DC's wintery weather the end of Global Warming?
Back in the Early 90's I worked at a famous international environmental organization. I remember many conversations about how to frame the emerging science that indicated CO2 emissions were changing the climate. Technically, we are changing the chemical composition of the atmosphere, but while that's accurate and descriptive, it's long, technical and boring. Instead of the more suitable but scientific sounding 'climate change,' the more sexy term 'Global Warming' won out.
The reality is: understanding what is going on with climate change means you understand the winter in Washington, DC doesn't refute climate change any more than a singular, previous dry and hot spell proved climate change. Day-to-day weather fluctuates but our human-induced climate change is raising global average temperatures. As that happens, models predict greater amounts of precipitation per event: exactly what is being shown by the data. In the report Global Climate Change Impacts in the United States research shows that the number of severe precipitation events are increasing with the NE United States increasing by 67% the number of very heavy precipitation events (defined as the heaviest 1% of all events) from 1958 to 2007.
These are data from actual measurements- not hypothesis. And before dismissing the work of groups like the United States Global Change Research Program (USGCRP) or the International Panel on Climate Change (IPCC) (a recent IPCC document mistakes the rate of melting glaciers in the Himalayas so "climate change deniers" dismiss the whole body of research), you have to understand the complicated science of climate change. These data and reports undergo some of the most thorough peer reviews of any scientific data on the planet but that won't mean every prediction is going to be true. However, I am impressed with how modeling and observations have aligned (though observations of change show the modeling was conservative).
One of the data pictures, or charts, I like to observe (and have posted about before) is AccuWeather's Sea Surface Temperature Anomalies (yeah, that's really going to work in today's sound-bite world!). What it is: a global picture of the top layer of the ocean - and if it's green, yellow or red that shows how much warmer from average it is, and if it's white or blue, how much colder it is. If you've been following this fascinating drama, you'll know that most of the time the picture is red and green- sometimes it is literally off-the-chart red, especially around the arctic. That's why the Arctic will soon be ice-free in the summer.
So where has Global Warming gone? I hope the phrase has gone away. Global Climate Change describes what is happening more accurately. Overall, the planet is warming, but that doesn't mean calm, even, warming temps- when an ice dam broke and the huge lake of melted glacial water flowed out of Canada, forming the St. Lawrence, the fresh water slowed the Atlantic conveyor, and cooled Europe in the process. But to think that a huge snowstorm, or series of storms means the end of warming, you're mistaken. Look at the past weather data and you'll see, for snowy Washington, DC's winter (using November '09, December '09 and January '10 Average Maximums and Minimums) you'll see that DC's winter has produced a slightly lower average maximum temperature (-0.5 degrees C) but slightly warmer average minimum temperature (+5.1 degrees C) for an overall WARMER winter than average.