PS, David, I'm aware of the 500-million-year decline you point to, but that's not what I was talking about. Each warming has had active biological cycling.
Evolution has worked quickly compared to the pace of the ice ages; each ice age cycle has had newly evolved organisms involved in the cycling of carbon Take the coccolithophores as one major example; sorry I don't know where to find a copy but this cite gets at how they changed from coastal to pelagic organisms, taking over the open ocean and so having far more ability to cycle carbon: de Vargas, C.; Aubry, M.P.; Probert, I.; Young, J. (2007). Origin and evolution of coccolithophores: from coastal hunters to oceanic farmers, in: Falkowski, P.G.; Knoll, A.H. (Ed.) (2007). Evolution of primary producers in the sea. pp. 251-285 This example is an old favorite article of mine: http://courses.washington.edu/ocean450/Discussion_Topics_Papers/Schmitz_et_al.pdf (as corrected: http://www.nature.com/nature/journal/v407/n6803/full/407467a0.html ) "... certain species of plankton characteristic of high-productivity regions flourished all over the world at the P/E boundary6. .... a large peak in biogenic barite ... at the P/E boundary indicates a dramatic increase in biological productivity7. Biogenic barite has proved a reliable proxy for surface-water biological productivity in the open oceans of the past7,8. The paper by Bains et al.1 not only provides new evidence that oceanic productivity did indeed increase, but also provides a feasible mechanism for how an episode of greenhouse warming may end. .... Bains et al. propose that higher productivity and the resulting sequestering of excess carbon in the oceans, through photosynthesis, was the feedback mechanism required to bring levels of atmospheric CO2 and temperatures back to normal...." -- You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/globalchange
