The global warming skeptics point to a faster warming trend before the '40s than after. There seems to be a pause in the trend in the '50s to '70s, then the trend begins anew. I have speculated that it was due to smog - the particulants in the air cooled the trend. The clean air act ironically increased global warming by making the atmosphere clearer. Now a Nobel scientist, Paul Crutzen, is proposing that smog be used to slow global warming - or more precisely, that particulants be injected into the upper atmosphere. He is confirming the view that smog slowed global warming, and now wants to reinterject smog but up high so as not to blanket our cities. Sounds plausible, but imagine that continuing for decades, centuries, as nations rise and fall ... Sometimes very smart people can come up with really dumb ideas.
I'm not surte the idea is so far fetched, considering our unwillingness to take climate change seriously. We may indeed need some kind of extreme stopgap measure like this in 30 years when CO2 levels are above 550 ppm, climate changes begin to get scary and very deadly, and panic sets in.
tim Flannery, Austrtalian scientist and author of "the Weathermakers" speculates that the water vapor contrails released into the upper atmosphre from jet air traffic are actually having a slight cooling effect, because they reflect incomming solar radiation, that at least offsets the CO2 emissions of those airplanes. (the water vapor is very short lived, so not appropriate as a serious stopgap measurte.)
The point is that Crutzen is not talking about ground level smog, but high altitude particles that reflect solar radiation before it can wqarm the earth, hopefully restoring the energy/heat balance of the earth and stopping the increase in warming that the CO2 is driving.
It is possible that soemthing like this could work. (yes it would be a big risky if with the earth as the test tube, but not necesarilly stupid. the stupid is putting ourselves in the situation where we might have to seriously consider something like it, and recogignizing our inability to deal with climate change until our options are dire is also not stupid, in fact it's pretty common sensecal.
Of course artifically cooling the earth in a manner like this is treating the symtoms, not the underlying cause. The CO2 will still be increasing in the atmosphere and in the oceans, and warmth is only one effect of that.
Posted by: Sibley | Sunday, November 26, 2006 at 08:26 PM
Sibley, I believe this sort of idea could work, but is not practical. This is not a long-term solution (think 100s of years) nor is it reliable. If it works, the pressure to do it will evaporate. If there is a major depression in western economies, the effort will be dropped for other priorities.
Posted by: yelnick | Sunday, November 26, 2006 at 08:59 PM
This (man made) global warming business appears to be junk science to me. Let's concede that global warming itself is a fact, but require proof that the major contribution to that undeniable effect is man made. An example question could be: How much green-house gases are generated by vulcanic activity and is that relevant?
Absent that premise being subjected to a thorough scientific peer review, I can only conclude that this global warming business is nothing more than a UN effort to increase its influence. And if you think that is far fetched, just think about the UN's push for global taxation authority.
Posted by: rdneu56 | Wednesday, November 29, 2006 at 06:01 AM
rdneu56, I can only suggest that you read The Scientific Consensus on Climate Change by Naomi Oreskes in the DEC 2004 edition of SCIENCE. *http://www.sciencemag.org/cgi/content/full/306/5702/1686
It is legitimate to question the motives of the UN (Here the IPPC). It is also true that we don't "know"for sure exactly how much warming is being caused by human activity, or what the consequences of this will be. But if we are to take the global scientific establishment at all seriously we cannot argue that the evicence points very strongly to human causes and lkiely significant trouble ahead.
Here is Oreskes:
IPCC states unequivocally that the consensus of scientific opinion is that Earth's climate is being affected by human activities
IPCC is not alone in its conclusions. In recent years, all major scientific bodies in the United States whose members' expertise bears directly on the matter have issued similar statements. For example, the National Academy of Sciences report, Climate Change Science: An Analysis of Some Key Questions, begins: "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise"
Others agree. The American Meteorological Society (6), the American Geophysical Union (7), and the American Association for the Advancement of Science (AAAS) all have issued statements in recent years concluding that the evidence for human modification of climate is compelling (8).
The drafting of such reports and statements involves many opportunities for comment, criticism, and revision, and it is not likely that they would diverge greatly from the opinions of the societies' members. Nevertheless, they might downplay legitimate dissenting opinions. That hypothesis was tested by analyzing 928 abstracts, published in refereed scientific journals between 1993 and 2003, and listed in the ISI database with the keywords "climate change" (9).
Of all the papers, 75% fell into the first three categories, either explicitly or implicitly accepting the consensus view; 25% dealt with methods or paleoclimate, taking no position on current anthropogenic climate change. Remarkably, none of the papers disagreed with the consensus position.
This analysis shows that scientists publishing in the peer-reviewed literature agree with IPCC, the National Academy of Sciences, and the public statements of their professional societies. Politicians, economists, journalists, and others may have the impression of confusion, disagreement, or discord among climate scientists, but that impression is incorrect.
Posted by: Sibley | Wednesday, November 29, 2006 at 03:29 PM
The characteristic of a junk science:
Hard facts and data are replaced by “reference to authority…” The mainstream media promulgates the consensus opinion and declares dissenters irrational, irresponsible or worse.
Posted by: rdneu56 | Thursday, November 30, 2006 at 05:30 AM