11 February 2010
Trust me on this. Don’t email your local meteorologist and say something like “What do you think of global warming now with all these blizzards?” You will come across rather silly if not down right ignorant.
Let’s think about it for a minute. Consider a few things before we jump to the keyboard. My grandmother always said you can’t say something silly if you keep your mouth shut. Something I have learned the hard way far too many times.
Yes, it has been the snowiest winter on record in Washington DC. Pretty bad in Boston and the Big Apple too. Those cities are less than 600 km apart. The planet is about 40,000 km around at the equator. The weather in the Northeast USA is not usually representative of the planet as a whole. Climate change IS affecting the entire planet though.
The Winter Olympics start Friday in Vancouver. They have been trucking in snow, because it has been so unusually warm! That’s no surprise either, because when Mother Nature brings the cold down to one part of the planet, she almost always compensates somewhere else.
You might wonder just what the planets temperature is right now??
The answer is unusually warm.
We just finished one of the warmest years on the instrumental record. The satellite measurements of the lower troposphere (The bottom part of the atmosphere where weather occurs) are actually indicating the warmest temps ever recorded using this method. The January surface data from NASA/NCDC is days away and I will lay odds it is near all time levels for January.
Another fact to consider is that weather and climate are two different things. If the temp. continues to warm another 4C by the year 2100, we will still have all time record lows and we will still have blizzards. The blizzards may not be as frequent, but they may very well have a lot more snow.
The reason is simple thermodynamics. Warmer air can “hold” more water vapor. The IPCC has estimated that the atmosphere has 4% more water vapor in it now than 40 years ago because of the warming we have already experienced. Even in a warmer world we will still see all time record lows. The all time record highs will far outnumber them though.
Doctor Jeff Masters is a Meteorologist who writes an excellent blog on the Weather Undergound site. He has a very good explanation of this on his latest post. Click the image and read it. I bet you will think twice before typing that email to your local weather geek afterwards.