Flawed Assumptions?

AGW predictions are necessarily rife with assumptions. Given the mission of the IPCC to bolster the hypothesis that manmade greenhouse gas emissions are causing harmful climate change, I am surprised to hear a fellow scientist (James Hansen not withstanding?) characterize IPCC predictions as conservative. For the sake of the planet, I hope that other flawed assumptions come to light and cast doubt on the dire predictions we hear on a daily basis. So far, though, it appears to work in only one direction...always for the worse. 
 
In the recently published paper by Susan Solomon, et al, \"Irreversible Climate Change Due to Carbon Dioxide Emissions\" (http://www.pnas.org/content/106/6/1704), she shows that climate change due to increases in CO2 will be irreversible for 1,000 years after emissions stop. What a bombshell. I wonder whether her conclusion relies on flawed or OVER-estimated assumptions. Let\'s hope so. It would be a breath of fresh air for all of us.

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