David Keith comes across as quite logical here, doesn't he? The failure to rein in emissions is the main, indeed the only rationale he gives for the necessity of his brand of geoengineering to be tried out. and since emissions reduction gets near-exclusive attention from public media and intergovernmental conferences, his arguments steadily gain in persuasiveness.
There is another failure in evidence, however: the failure to see climate change as a natural process that may be reversible if understood not just in technological terms but as a largely biological process. Participants in this list debate the distinctions between SRM and CDR which define technological handles to be applied to the earth's atmospheric and oceanic envelopes; I would caution however that without the complex ecologies created by millions of other species our power to manipulate the climate would be nonexistent. In engineering terms, reversal of overall climate warming trends clearly requires massive sequestration of atmospheric CO2, which is not addressed by Keith's methods. Yet CDR as an alternative is, I think, an ambiguous category because "removal" is ecologically meaningless. Where is the "removed" carbon to be disposed of? The ongoing boondoggle of CCS is a painful example of technological solutions that have no relation to natural cycles; it treats carbon like some poison that needs to be locked away forever. Some methods offered under the category of CDR do indeed support natural cycles, however. Biochar for example certainly has a place in sequestering carbon in soil and jumpstarting microbial communities. I would suggest that the way to correct climate imbalance is not to "remove" but to *use *carbon in the ways it has been used since long before humans learned engineering. The ecological effects of desertification, deforestation, and industrial agriculture are all demonstrably harmful practices which humans have imposed on the biosphere; isn't it self-evident that reversing climate change can be accomplished by reversing these disastrous practices? Brian Cartwright -- 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. For more options, visit https://groups.google.com/d/optout.
