List: 1. I believe this article from last week's Science could be valuable to this list, although there is (close to) zero mention of either side of geoengineering: Irreversible Does Not Mean Unavoidable ; H. Damon Matthews 1 and Susan Solomon 2
Science 26 April 2013 : Vol. 340 no. 6131 pp. 438 - 439 DOI: 10.1126/science.1236372 2. I hope someone can help me understand the use of "Irreversible" in the title and, as an example, in the final paragraph: "Given the irreversibility of CO2-induced warming ( 5, 6), every increment of avoided temperature increase represents less warming that would otherwise persist for many centuries. Although emissions reductions cannot return global temperatures to preindustrial levels, they do have the power to avert additional warming on the same time scale as the emissions reductions themselves. Climate warming tomorrow, this year, this decade, or this century is not predetermined by past CO2 emissions; it is yet to be determined by future emissions. The climate benefits of emissions reductions would thus occur on the same time scale as the political decisions that lead to the reductions." Cites 5 and 6 are: 5. S. Solomon, G. K. Plattner, R. Knutti, P. Friedlingstein, Proc. Natl. Acad. Sci. U.S.A. 106, 1704 (2009). 6. H. Matthews, K. Caldeira, Geophys. Res. Lett. 35, L04705 (2008). 3. Believing that CDR is real and alive, I would have preferred to see this (my emphasis added) as: Given the reversibility of CO2-induced warming, every increment of avoided temperature increase represents less warming [x, y] that would otherwise persist for many centuries. Because emissions re movals can return global temperatures to preindustrial levels, they do have the power to avert additional warming on the same time scale as the emissions reductions themselves. Climate warming tomorrow, this year, this decade, or this century is predetermined by both past and future CO2 emissions and removals The climate benefits of emissions reductions and removals would thus occur on the same time scale as the political decisions that lead to the reductions. My cites (x and y) might be from Jim Hansen and Bill McKibben, but also this list, the Royal Society and the new NRC study all of which describe various CDR approaches. All mistaken? I ask why this second version should not be the more accurate. 4. In defense of the authors, whose work I otherwise uniformly admire, I think the intended word rather than "irreversiblity" might have replaced "ir" with (awkwardly) "non-utilized" or "un-utilized". The "ir" strikes me as guaranteeing a physical impossibility, for which no proof is offered. I think this important as CDR gets too little attention anyway, to be saddled with "irreversible" Thoughts? Ron -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
