Global Dimming Further Verified
January 15, 2005
In a nutshell: it has been shown the amount of sunlight reaching Earth's surface has been decreasing over the last several decades. This decrease is attributed to particulate matter introduced into the atmosphere by human behavior (i.e soot, chemicals, CO2, etc.). Of course, with less sunlight reaching the surface, the effects of global warming are somewhat mitigated...
Which is leading some numbskulls to say that reducing pollution will only make global warming worse. Apparently this journalist (and countless others) just doesn't get science (probably one of those breed who still writes that scientists disagree about global warming, when this is really not the case. Definitely human influenced if not induced).
It does seem to be true that global warming will get worse if we reduce pollution and do nothing else, thanks to this dimming effect. However, it must be noted that dimming has many negative effects that may outweigh its attenuation of warming trends. First of note is the effect on rain patterns, which have already been severely altered by extensive logging (forests help produce rain clouds, and hold in water that does come down). As the BBC explains, "Scientists are now worried that dimming, by shielding the oceans from the full power of the Sun, may be disrupting the pattern of the world's rainfall." Columbia University's Earth Institute News has more thorough coverage of dimming in general and effects on rain in particular.
Other effects that come to mind: how does reduced sunlight impact crop yields? solar power generation? And of course the cause of the dimming is also the cause of acid rain — man-made particulates with high-levels of sulfur or nitrogen — which as we know causes all kinds of problems.
worldchanging.com explains what we can about both global warming and global dimming:
"The real implication of this story is not that efforts to reduce fossil fuel use are pointless, but that we need to redouble our efforts to mitigate greenhouse effects. These efforts take three key paths: methane (CH4) emission reduction, to slow shorter-term (3-10 year) greenhouse effects; carbon sequestration to reduce the amount of atmospheric CO2 in the short-to-medium-term; and CO2 emission reduction, to slow and stop medium-term (50-100 year) warming."