Geoengineering is the mindful use of human activities to adjust our climate.

We've been doing this unmindfully for ten generations, exhuming carbon until we pushed the atmospheric CO2 concentration a hundred parts per million outside its normal bounds. We're going to have climate change even if some slate wiper virus takes the whole human race over the next few weeks. There are already positive feedbacks in motion like the thawing and decay of permafrost releasing methane, a greenhouse gas 23x more potent than CO2.

Most of the geoengineer proposals seen are either daft or thinly disguised retrograde efforts conceived to benefit the fossil fuel industries. The most common (and foolish) one heard is that we should use sulfate aerosols to increase the Earth's reflectivity and lower temperatures that way. This actually happened from the 1940s to the 1970s due to all of the high sulfur diesel we burned. Allowing ultradirty diesel back into use so we can have a little reflectivity now (and a lot of acid rain later) does not seem like a very good plan.

Dr. Homer Wang, a far ranging thinker on climate change issues, has what appears to be the only sensible geoengineering proposal going with a chance to actually work. We've written about this at length before, but the executive summary is this: There is a lot of stranded wind in the arctic, which could be used to make ammonia and ice, producing a carbon free fuel in winter and increasing reflectivity of the ocean in summer.

The details of Dr. Wang's proposal are found here:

http://strandedwind.org/node/41