"Defying expectation and easy explanation, hundreds of instruments around the world recorded a drop in sunshine reaching the surface of Earth, as much as 10 percent from the late 1950's to the early 90's, or 2 percent to 3 percent a decade. In some regions like Asia, the United States and Europe, the drop was even steeper. In Hong Kong, sunlight decreased 37 percent.Yeah, and I'll confess that this is the first I've heard of 'global dimming' raised as an issue. Kind of makes sense, that it would raise a great deal of issues, and pretty damn significant ones even if the rate is the much lower rate:
No one is predicting that it may soon be night all day, and some scientists theorize that the skies have brightened in the last decade as the suspected cause of global dimming, air pollution, clears up in many parts of the world.
Yet the dimming trend - noticed by a handful of scientists 20 years ago but dismissed then as unbelievable - is attracting wide attention. Research on dimming and its implications for weather, water supplies and agriculture will be presented next week in Montreal at a joint meeting of American and Canadian geological groups.
'There could be a big gorilla sitting on the dining table, and we didn't know about it,' said Dr. Veerabhadran Ramanathan, a professor of climate and atmospheric sciences at the University of California, San Diego. 'There are many, many issues that it raises.'"
Dr. Beate G. Liepert, a research scientist at the Lamont-Doherty Earth Observatory of Columbia University, has analyzed similar information and arrives at a smaller estimate of the dimming than Drs. Stanhill and Cohen. Dr. Liepert puts it at 4 percent from 1961 to 1990, or 1.3 percent a decade. "It's a little bit the way you do the statistics," she said.Yeah, and it is all about how you do the statistics, and that's why I'll reserve any judgement until I get a little more info. And I'm a little puzzled by the closing:
But clearer, sunnier days could mean bad news for global warming. Instead of cloudiness slowing rising temperatures, sunshine would be expected to accelerate the warming.Does that mean I should crank the fireplace, idle the car up, and burn my lawn clippings? Probably not; probably I'd bet on this being one mean wicked problem if the rate of change in light fall is as cited.