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Index of Subjects Hi Dave, On 10-Jun-08, at 8:02 PM, David & Alison Webster wrote: > Figure 1a shows without doubt that temperature, CO2 & CH4 are > related but--- temperature starts to increase BEFORE CO2 & CH4 > start to increase. There may subsequently be positive feedback, but > at least initially, higher temperatures are driving CO2 & CH4 > increase not the converse. > > I suppose one could call this 'tceffe esuohneerg a' but it would > be awfully difficult to pronounce. You must have preternaturally acute vision to be able resolve this from Figure 1a. :-> I'm looking at it at the moment and, as you point out, does show a clear historical relationship of temperature, CO2, and CH4 but the graph, which represents 800,000 years, is only 3.75" wide on my screen. At that level of resolution, these graphs, set one over the other, look absolutely co-incident to me. I tried printing this out and running a vertical rule over it, but I don't see how one could possibly discern whether temperature, carbon dioxide, or methane are increasing before or after one another at this resolution. :-> There is a lot of very interesting information in this Nature article by Ed Brook on paleoclimatic history. It's astonishing that we now have an 800,000 year old climatic record, and even more amazing that the IPICS (International Partners in Ice Core Sciences), has set itself the target of establishing a continuous 1.5-million-year record which they believe they can do from drilling at other sites in the eastern Antarctic. Most germane to the present discussion on climate change is Brook's statement that, "The fundamental conclusion that today's concentrations of these greenhouse gases have no past analogue in the ice-core record remains firm." Methane concentrations over the past 800,000 years have fluctuated between 400 and 700 p.p.b. whereas presently they are spiking at 1,800 p.p.m. (about triple the historical average), and all of this increase appears to have taken place in the last century. Similarly, carbon dixoide, which has fluctuated between 180 and 300 p.p.m. over the past 800,000 years, is now in the range of 380 p.p.m., and again all of this historically unprecedented increase appears to have taken place in the last century. This is another important scientific finding that underscores the dramatic scale of contemporary anthropogenic climate change. It is science such as this that bears out the reality of climate change, and not petitions one way or the other. These are sobering findings that we cannot afford to ignore. All the best! Chris Christopher Majka - Atlantic Canada Coleoptera http://www.chebucto.ns.ca/Environment/NHR/atlantic_coleoptera.html c.majka@ns.sympatico.ca
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