On this issue of the desperation of our situation, as I noted in a paper last year (see http://www.climate.org/PDF/MacCracken-CritReviewSummary-final.pdf ), and later confirmed using Wigley's MAGICC model, consider the following:
A) If emissions from the developing world went to zero next year and stayed there, the trajectory of developed nation emissions (even considering a reasonably low emission IPCC SRES scenario) would take the world to greater than 2 C warming, only about a decade or two later as compared to at present. Clearly, the developed nations have to go to virtually zero GHG emissions over coming decades. B) If emissions from developed nations went to zero next year and stayed there, the trajectory of developing nation emissions (again considering a reasonably low scenario) would also take the world to over 2 C, delayed by a little bit more. Clearly, the developing nations are going to have to also get their emissions down toward zero. For reasons of both practicality and equity, developed nations need to lead on CO2, showing the world that a modern economy can prosper on low CO2 emissions. But both developed and developing nations can really reduce near-term forcing (and so warming) by cutting their non-CO2 emissions (methane, black carbon, ozone generating air pollutants, etc.--and controlling each of these can improve health and well-being now and/or improve overall economic efficiency) and by taking steps to improve efficiency and end deforestation/start reforestation. Roughly speaking, the 21st century warming influence of 21st century emissions of non-CO2 greenhouse gases is nearly as much as the 21st century warming influence of 21st century emissions of CO2 (of course the CO2 effect carries on for centuries and longer). So, if we want to slow warming, negotiators must work toward an agreement that limits both CO2 and non-CO2 emissions. And the point is starting to get through to high levels (see http://www.guardian.co.uk/environment/cif-green/2009/sep/11/co2-other-cause- climate-change). So, while keeping below 2 C will still be hard if we also control non-CO2 greenhouse gases (and the world may still want and need geoengineering to keep the warming down and deal with special impacts like the Arctic because cutting CO2 emissions will also cut SO2 emissions and the aerosol cooling offset we have now), if the negotiating focus is only on CO2 emissions, we'll all be getting a good bit warmer and the pressure for geoengineering will be even greater. Mike MacCracken On 9/17/09 10:07 AM, "Andrew Lockley" <[email protected]> wrote: > > The clear message is that: > 1) Even if we stopped emission completely tomorrow, we'd probably > still be in deep trouble. It is abundantly clear that we face not > one, but several potential major tipping points, as identified by > Lenton et al. > 2) Without urgent and significant funding for geoengineering research, > the technologies will be unlikely to be ready for swift and safe > deployment when needed. > 3) The later we can deploy any necessary geoengineering, the less > likelihood there is that these technologies will work effectively. > > > A > > 2009/9/16 John Nissen <[email protected]>: >> >> >> Albert is seeing ex-president Clinton next week. This is an unusual >> opportunity to a get a message across to somebody with real influence. >> Is there a single message that could catalyse action? >> >> Seeing the bad news in the Guardian [1], about which Stephen sighed, one >> should not be "rocking the boat", yet I feel that the people advising >> Obama must warn him that emissions reductions, however severe, are no >> guarantee of safety. Any level of emissions reductions which appear >> politically acceptable, like 80% reduction by 2050, has little chance of >> preventing tipping points like Arctic sea ice summer disappearance. >> >> Perhaps Clinton should be told that we actually face a climate >> emergency, but IPCC have dug themselves collectively into a hole over >> emissions reductions. Scientific advisers (like John Holdren) should be >> asked a straight question: would emissions reductions by themselves >> guarantee to prevent the kind of climate catastrophe that could follow >> from loss of Arctic sea ice (methane discharge, sea level rise) - and if >> not, is there any alternative to geoengineering for significantly >> reducing the risk? The answer does not have to be made public, but that >> is another issue. >> >> Cheers, >> >> John >> >> >> [1] >> >> http://www.guardian.co.uk/environment/2009/sep/15/europe-us-copenhagen >> >> >>> >> > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. 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/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
