Did water vapor drive climate cooling?


  • Michael Carlowicz


In attempting to explain the abrupt and drastic changes in global temperatures observed during the late Quaternary period, it is possible that atmospheric scientists and paleoclimatologists are mistaking the impetus of those changes for a mere amplifier. This is the hypothesis of Wallace Broecker, who has synthesized global climate observations in order to assert that water vapor—and, particularly, moisture levels arising in the tropics—may be the only atmospheric component capable of warming and cooling the Earth on short notice. Broecker, a geochemist at the Lamont-Doherty Earth Observatory, presented his ideas in the Daly Lecture at the AGU Spring Meeting.