A single coal fired plant will indeed cause net cooling before it causes net warming, so a sufficiently rapid deployment could in principle cause short term cooling. However, the aerosol effect of large scale coal plants is surprisingly small, so presuming that the Chinese are not building ridiculously outdated plants in practice this is not a matter worth worrying about.
See p 3 of this powerpoint: http://www-new.mcs.anl.gov/climate/cwg/slides/ANL_CCW_Streets.ppt Aerosols are dominated by low-tech burning of fuels for heat, and by cheap, primitive factories and motors. This talk also indicates that global aerosol emissions have a slightly downward trend while greenhouse gases march inexorably upward. mt On 3/18/07, James Annan <[EMAIL PROTECTED]> wrote: > > > [EMAIL PROTECTED] wrote: > > We all know Lindzen's line about greenhouse gas forcings already being > > 70% of doubled CO2, and the response that that doesn't mean a 2C > > increase right now, because of aerosols and thermal lag. > > > > What I am wondering about is what would the effect of sudden changes > > in aerosol production from coal fired power plants be? > > > > Would shutting down all coal fired power stations over night yield a > > rapid jump in temperatures, as aerosols are washed out of the > > atmosphere within months? > > There would be a rapid increase in forcing, but in broad terms this > would only result in a change in the _rate_ of warming, not a step > change in the temperature itself. > > (Local effects could be more rapidly obvious, I expect.) > > > > > And, > > > > if you believe Chinese statistics on coal burning, there's been a huge > > jump recently, > > > > mighn't that, the short term at least, actually depress temperatures? > > Well it would probably tend to offset the CO2 forcing and perhaps might > be negative overall. > > > > > > Would anybody here know whether there's a study on the matter/ > > There have certainly been studies simulating different components of the > forcing, eg omitting all aerosols over the 20th century. The effect is > clearly noticeable but not overwhelming on the global scale. > > James > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
