Professor Peter Stott:

I was alluding to the issue of geoengineering. Faced with these challenges, one proposition being made is that perhaps there is another way to keep global temperatures from increasing by 4° Celsius or 5° Celsius. One suggestion is that if dust were to be put very high in the atmosphere, it would cool climates. This is basically mimicking what happens naturally when there is a big explosive volcanic eruption. There was one example of that in 1991 when Pinatubo exploded. That temporarily cooled the climate for a year or two before the dust fell back down out of the very high atmosphere. One could say that perhaps that could be done artificially, but there are a couple of issues to think about with that. The one I alluded to is that it would not deal with the fact that we are continuing to pump carbon dioxide into the atmosphere and, therefore, continuing to make the ocean more acidic. The second point is that it has major impacts on rainfall patterns. Doing such a massive thing to the climate has massive impacts.