global warming vs. global dimming
#1
global warming vs. global dimming
Did anyone catch Nova last night on PBS? Scary stuff...
One part of the show discussed how man-made global warming, caused by greenhouse gas emissions, have been partially offset over the years by global dimming, a phenomenon where pollutants from the same processes block or deflect some of the sun's rays, causing the opposite affect - global cooling.
While warming holds a significant edge over cooling, the cooling portion did help offset the warming significantly. Since scrubbers and catalytic converters and other polution prevention methods have taken hold, polution output in North America has been reduced significantly, thus tipping the balance much further towards warming.
Towards the end they reported that there are vastly different models that scientists use on the affects of all this on global temperatures, but one (admittedly closer to worst case) scenario had the earth gaining 25 F by 2100. If you want to invest in your great, great grandkids future, you might want to think about picking up some land inland from the Hudson Bay....
One part of the show discussed how man-made global warming, caused by greenhouse gas emissions, have been partially offset over the years by global dimming, a phenomenon where pollutants from the same processes block or deflect some of the sun's rays, causing the opposite affect - global cooling.
While warming holds a significant edge over cooling, the cooling portion did help offset the warming significantly. Since scrubbers and catalytic converters and other polution prevention methods have taken hold, polution output in North America has been reduced significantly, thus tipping the balance much further towards warming.
Towards the end they reported that there are vastly different models that scientists use on the affects of all this on global temperatures, but one (admittedly closer to worst case) scenario had the earth gaining 25 F by 2100. If you want to invest in your great, great grandkids future, you might want to think about picking up some land inland from the Hudson Bay....
Last edited by toast64; 04-20-2006 at 04:43 AM. Reason: sp
#2
Re: global warming vs. global dimming
Yep. It's amazing how well the Earth can fix itself. Three days after 9/11 without planes and their contrails and the skies cleaned up quickly. Too bad the average temperature range shot up by 2 degrees C. We need to lower GHG emissions but keep particulates high until GHG is so low it's non-existent. Then we can clean up particulates.
#3
Re: global warming vs. global dimming
Originally Posted by Sledge
Yep. It's amazing how well the Earth can fix itself. Three days after 9/11 without planes and their contrails and the skies cleaned up quickly. Too bad the average temperature range shot up by 2 degrees C. We need to lower GHG emissions but keep particulates high until GHG is so low it's non-existent. Then we can clean up particulates.
#4
Re: global warming vs. global dimming
As we speak, the European Venus Express just went into orbit, to investigate it's hot murky atmosphere...
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