Not More Global Warming? ARRRGH!
More cries of Global Warming are in the News. One of our Ex-Vice Presidents is even on the band wagon tooting his horn. There is no question that we are enjoying warm/dry summer temperatures that relate to the latest cycle of drought that mother nature has provided us. It seems that this year's drought is a continuation of the one that started in the late 1990s. The 1999 to 2006 drought now ranks only behind the 1930s and the 1950s, which makes the current weather equal to the third worst drought on historical record. Ground zero of this drought is in south central North Dakota down to central South Dakota, but other dry spots scatter across the nation.
The drought of the 1950's lasted five years, and affected much of the central and southern Great Plains. Starting in 1930, the great Dust Bowl lasted about seven years. It actually affected almost 70 percent of the land area of the United States, affecting regions from New York across the Plains to California. The summer of 1930 will not be exceeded in its severity this year. Much more severe central continent prehistorical droughts, (known from tree ring data, lake/river/sand dune sediment analysis, and archaeological evidence), occurred from 1580 to 1600, and the last quarter of the 13th century. The good news is that prior to the 13th century, droughts were MORE severe/MORE frequent and LONGER lasting than now. Apparently a long term moderating trend has been underway.
No matter what the cause of the hotter planet (man made or natural cycle), a warmer world will experience greater hydrologic extremes. Warmer land will evaporate water faster than the ocean (which warms more slowly), which will lag behind providing enough water vapor to balance the cycle. Precipitation will not keep up with evaporation, and therefore more droughts are predicted on a warmer planet. Big cities are definitely getting relatively warmer. Concrete surfaces, asphalt and bricks retain heat very effectively. The surrounding countryside is usually several degrees cooler because of evaporation from the open porous surfaces. Hard surfaces like pavement have no evaporative cooling to contribute, and urban areas suffer as a result.
I emphasize that all weather is local, and anyone predicting weather 50 years in the future has a problem. I dare any forecaster to predict the temperature next Christmas Day to a degree, let alone predicting that global temperature will rise by X number of degrees in 100 years. Take it from a non-biased earth scientist that you should not believe propagandistic "documentaries" that make claims on the causes of "global warming". In the 1970's, the big story was that we were going into a new ice age. Nature is full of cycles, but it isn't always easy to see them. Some researchers are more predictable based on their funding cycles. Research is big business.
This summer's high temperatures have not escaped the environmentalists' notice. They claim that man's activities are responsible for the current high temperatures. High temperatures are common mid-summer with the last week of July usually being the hottest of the year. I don't suppose that populations suffering from the latest heat wave will find any comfort in the past temperature record that indicates it has been hotter in the past. It will get hotter in the future and colder in the future. If you don't like the weather, just stick around, it will change.