Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
If a temporary SO2 sunscreen can reduce global temperature the way Pinataubo did, great.  And probably using coal-fired plants to do it, as Migeru suggests, would be to rely on technology already in place. But the expense of modifying scrubbers to permit SO2 release will not be undertaken voluntarily by utilities.

In any case, we also must mitigate CO2 on a large scale.  There is a limit to how much carbon dioxide forests, deserts, and soils and can take up before they start expelling CO2 into the atmosphere.  

Forgive me for repeating a comment I posted on Techno's Ocean Acidification diary:

The ocean is a tremendous carbon sink.

Oceanographers I've talked to are thinking that the changes in ocean temperature are too rapid for many species to adapt.  The acidification rate of the ocean may also be too rapid for adaptation of species.

At present carbon emissions from human activities continue to increase at a steep rate.  

Meanwhile, the increase in ocean temperature is speeding up the chemical processes of acidification.  This is ultimately bad news for critters with exoskeletons. And for the food chain.  One billion people rely on the ocean for food.

If the present acidification due to carbon absorption continues at the present rate, erosion from terrestrial rock will not supply enough buffering to counter the acidification.  At some point the ocean will fail as a carbon sink.  So the carbon will remain mostly in the atmosphere, creating a rather Venusian environment.

In this scenario, there's a tipping point that will be catastrophic unless drastic reduction of carbon emissions are undertaken.

by Plan9 on Sat Oct 14th, 2006 at 10:16:53 AM EST
[ Parent ]
Modifying coal power plants is easy:  The scrubber that removes SO2 by reacting it with lime doesn't remove anything else of note, so you just take it out.  The problem is that you don't want SO2 in the lower atmosphere.  It doesn't stay there, instead it causes smog and gets washed out as acid rain.  Bad idea.

Neither forests, deserts nor soils are carbon sinks, only (very limited) carbon stores.  To remove CO2 from the atmosphere, you have to create organic matter and then bury it.  As a first step in that direction, do not use recycled paper.  Making paper and burying it in landfills is the only human-caused process that puts carbon back into the earth.

Earth will never become comparable to venus.  Our oversized moon prevents earth from accumulating such a thick atmosphere.  Also, please try to stay reasonable.  We're talking about 380ppm CO2 on earth while venus has 965000ppm CO2.

by ustenzel on Sat Oct 14th, 2006 at 06:09:52 PM EST
[ Parent ]
Good points all.  Thanks.

The Venusian reference was irresistible, but, as you say, an exaggeration.

by Plan9 on Sun Oct 15th, 2006 at 12:07:03 AM EST
[ Parent ]


Occasional Series