re: Science by public demand?
I said "Where they get "it will take hundreds of years to return to the way it was before the industrial revolution" might be fun to track down."
"The atmospheric lifetime is defined as: "the burden (Tg) divided by the mean global sink (Tg/yr) for a gas in a steady state (i.e., with unchanging burden)" (IPCC 2001, page 247). That is, if the atmospheric burden of gas x is 100 Tg, and the mean global sink is currently 10 Tg/yr, the lifetime is 10 years. The atmospheric lifetime of carbon dioxide is difficult to define because it is exchanged with reservoirs having a wide range of turnover times; IPCC 2001, (page 38) gives a range of 5-200 years."
http://cdiac.ornl.gov/pns/current_ghg.html