A new modeling study by Ken Caldeira (who coined the term "ocean acidification") and Damon Matthews suggests that even if anthropogenic carbon emission ceased today, the "pulse" of carbon dioxide emitted since the Industrial Revoluation would linger for half a millenium or so, and continue to warm the Earth for that entire time. "Even if we eliminated carbon dioxide today we are still committed to a global temperature rise of around 0.8 degrees C lasting at least 500 years," Caldeira told New Scientist.

Below is a table showing the resulting temperature increase after their model ran for 500 years with various single 'pulses' of CO2. The red numbers indicate the size of the current CO2 pulse, and the resulting temperature rise predicted by Matthews & Caldeira. The implication: even if CO2 emissions stopped today, we're committed to continued global warming for a long time.

Size of CO2 pulse (in gigatonnes of carbon) ................. Temp. change after 500 years (degrees C)

50 ........................................... + 0.09

200 ......................................... + 0.34

500 ......................................... + 0.88

2000 ......................................... + 3.6