Essay I wrote in early 2007 on an older website:
During the 2 days following September 11th, the absence of air traffic allowed scientists to analyze the effect of pollution from airplanes (or lack thereof) on the US climate. They found that the absence of particules usually released by airplanes actually increased US temperature variations during these two days (day-night variations).
While air pollution increases temperatures (greenhouse effect, producing global warming), the release of particules consequent to that pollution tempers that increase (this is also known at global dimming).
In other words, we are not seeing the effect of golbal warming today, we are only seeing the difference between global warming and global dimming. Once global dimming receeds, global warming will go into high gear.
September 11 showed us that it takes less than 3 days for global dimming to take effect (particules released in the air will reduce sun light on Earth in the following days).
We also know that it takes ~ 20 years for global warming to take effect (the time the greenhouse gases go into the upper atmosphere) and even about 50 years for the ocean temperature to be affected (due to its mass).
What we have today is the warming from pollution 20 years ago, tempered by the dimming from today's much higher pollution.
During the beginning of the oil depletion phase, while the consequences of a frantic consumption of oil and coal at the peak will be slowly accelerating warming (20 to 50 years lag), the progressive reduction of particules in the atmosphere (due to oil depletion - we will be using less fossil fuels) will also increase warming.
During the 20 first years of the energy descent, we will have two events compounding their effects on the climate.
If you are already living in a hot place, MOVE!!!