G'Day, Have to say that the thought of global warming really does impact my kayaking. I now frequently avoid car shuffles and hope for a wind change at midday to follow me home. I sometimes avoid gauntlets to avoid the greenhouse emissions from hospital treatment (but mostly coz I'm frankly scared). As for eating on the water it's strictly high carb' and healthy. All this might mean the kayaking experience has improved, but are such as I deluded? As the old, unhealthy, dangerous and time wasting ways exert their siren call I search the scientific literature for counter arguments to global warming, as any scientist, or kayaker yearning for a dangerous gauntlet or steak and chips should. All in the hope of discounting anthropogenic global warming. After all who wants it! Over the last twelve years there's been a change in the position of scientist/sceptics - I wonder how many people are aware of the growing concensus between 'sceptics' and climate change 'advocates' in some quite fundamental areas. Initially even the basic idea that atmospheric CO2 contained a significant level of man made CO2, and that it could make any difference to temperature, was disputed. These days most perhaps all of the sceptics who are scientists acknowledge the presence of man made CO2 and the direct physical relationship between changes in CO2 and temperature known as climate sensitivity. The current theoretical debate between sceptics and advocates seems to be principally about the value of climate sensitivity (between about 0.5 and 1.2 degrees C for a doubling in CO2-e); or the degree to which feedback systems might attenuate or amplify the change due to climate sensitivity. And of course these are crucial area's to get right, as without feedback the change would be about 1 degree C, with negative feedback it could be a fraction of a degree C and with positive feedback it could be many degrees C. Sometimes those who advocate minimal warming or even cooling will argue their point of view while presenting data that suggests the opposite. If like most scientists including sceptics, one accepts the idea of climate sensitivity, and compares changes in atmospheric CO2 with the average change in temperature since the industrial revolution of about 0.7degrees C, then theres a pretty good correlation. It might be slightly improved by introducing a small positive feedback. If one tends towards believing the lower limit of climate sensitivity as many sceptics do then a much greater degree of positive feedback has to be invoked and yet this is the very concept that is abhorrent to sceptical thinking as it relies so much on mdoelling. So I'm not getting much reassurance from reading even the best of the climate sceptic papers especially those that advocate the lower limit of climate sensitivity. Lets say that positive feedback is on the low side. Do one or two degrees C matter? Well by analogy think of the surf. A 1 metre 4 second period wave is fairly insignificant for a landing, but a 1 metre 15 second wave is starting to look serious. Likewise a local regional temperature rise of 1 or 2 degrees might be insignificant but worldwide could make a major difference to climate. As for values of change greater than a degree C due to positive feedback, we really have to wait many decades to see data that improves the statistical significance of observations and as Dave pointed, without the benefit of a control experiment. Can we afford to wait? What has all this got to do with kayaking? I don't really know, but if you ever come across one of these in the ocean http://en.wikipedia.org/wiki/Argo_(oceanography)#Float_design do treat it with respect as its one of 30,000 such measuring instruments that can submerge for ten days, dive to 2km, measure temperature and salinity on the way down and up, and then transmit the data to a satellite where it becomes available for any of us to read. Cute as a bugs ear and perhaps our best hope of accurate information on climate change from the oceans. But we're going to have to wait a long time - 7 years doesn't really cut it in the statistical signifcance stakes for this kind of study. All the best, PeterO (Who earns his living investigating ways to save energy and reduce carbon footprints, but who could just as easily earn a living finding alternatives to our vanishing oil reserves, or even better retire and go kayaking.) *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Fri Nov 27 2009 - 00:44:35 PST
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