The 9/11 effect when airplanes where grounded supports that this will be and issue. And as Andrew noted above our carbon sinks my be getting full.

This article is extreme and I don't necessarily agree with its conclusions but it seems to have a lot of info.
http://www.alternet.org/environment/32903

I used Dust Bowl as and example no telling what will really happen since the pollution patterns are different now.

The key point is that most of the evidence indicates that current C02 levels are sufficient to put the earth on a warming trend as has occurred naturally in the past. In fact they are probably a lot higher than levels that actually triggered a warming cycle in the past.

This suggests that natural feedback loops are already running and its doubtful we can stop the warming the only issue is how high will it go ? Probably continued use of fossil fuels at this point makes the eventual peak temperatures exponentially worse as trends are accelerated and loops run faster then they ever have in the past. Not only have we probably triggered a major warming trend but we probably are supercharging it.

This is where thoughts about local climate issues i.e global dimming because of pollution are important. I suspect we have a lot of micro feedback loops we triggered methane release etc etc that will cause a lot higher temperatures and faster warming then the global models indicate. I don't think they really model this sort of spreading micro climate change.

Think of it like a lot of isolated bacteria growing exponentially in their local environments then covering the whole area. Or think about a large glass window and shoot small pellets randomly at the window. Each pellet leaves only a small crack but even with a random pattern the entire window is soon shattered.

Our climate models can't really model this sort of concept its outside the scope but it does suggest that if this is right then the models are off by several orders of magnitude in their results both in time and in extremes.

The recent changes in arctic ice cover which are from a similar concept un-modeled cracking and erosion of the ice is a huge factor its effectively the same as the pellet idea and it seems to have result in a order of magnitude faster decline. So a high end projection would basically take our current climate models and multiply the temperature changes by ten and dived the time intervals by 10.

I really think that by doing this you get something thats within a order of magnitude of what will really happen. It may be twice as fast or extreme as what really happens but its much closer I suspect than our current models. Thus something forecast to happen in 100 years probably will occur within 10 or 20 years.

Before mankind forest fires probably played the role of providing global dimming early in a warming cycle only to have even faster warming once they ended.

Eventually as far as I can tell the cycle ends with large deserts on the continents and wind blowing dust into the ociean causing alagae blooms and plankton blooms eventually resulting in large oil deposits.
We have this right now with the Sahara for example so think of most of the world looking like the Sahara for say up to 1 million years before the system finally cools.