I’ll bet you right now that the record warmth in the eastern USA this past winter will be used as justification to claim global warming in accelerating. After all the twin centers of the universe, DC and NYC both have been warm…so the world must be warming! I don’t think so.
I live in Anchorage, in South-central Alaska. The region is bounded by the Pacific Ocean on the south and the Alaska Range (which includes Denali, the tallest mountain in North America) on the north. We have a maritime climate that is warm for the region because of our proximity to the water.
We have had a really cold winter this year with near record snowfall. February was a very cold month in the Arctic too with rapid expansion of the Arctic Ice Pack. All the while Chicago had 80 degree F weather in March. Record warmth all over the north-eastern USA and near record cold in Alaska.
One might be tempted to draw climate conclusions from regional weather variations…and that would be a mistake. Regional variations are common and very difficult to predict . When the data is looked at worldwide the highs and lows tend to cancel each other out.
That is exactly what is happening this year.
Routinely Alaska has warm winter weather when Chicago is cold and vise versa. When South-central Alaska has mild winter weather it is because the jet stream develops a long north south loop and warm air gets pulled up from the Pacific. This same loop pulls cold air from western Canada into the mid western USA.
This year the tropical jet is sending warm air to Chicago from the Gulf of Mexico and we Alaskans have been left out in the cold.
An easy way to demonstrate the assertion that regional climate is not important climatically is to look at global temperature sets. My favorite sites use low troposphere satellite data. The data provides a global temperature that does not rely on surface temperature data and I like that. Global warming theory predicts warming of the low troposphere before the surface, so it should be an indicator of future warming.
Four different agencies calculate the global temperature using satellite data. There are slight variations in how the data is interpreted, but they all paint a similar picture. UAH, the University of Alabama at Huntsville is one of the four sites. One of the principal scientists at UAH is Dr. Roy Spencer. Each month he provides an update to their data set on his website Here is the link to that website.
And here is the chart updated in early March, complete with February 2012 data.
As you can see, the world has been cooling slightly for about 6 months, and was just a bit below the average of the last 33 years in February. In fact this data supports the notion that, if anything, we have been in a slight cooling cycle since 1998.