Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Politics : View from the Center and Left -- Ignore unavailable to you. Want to Upgrade?

To: Ilaine who wrote (17277)	4/28/2006 1:24:42 PM
From: Mary Cluney	Read Replies (1) \| Respond to of 541457

CO2 stays in the atmosphere for several hundred years. Does this statement make sense to you? Did you study chemistry and biology? You got me. I studied both biology (101 and 102) and chemistry (101 and 102) in college more than 50 years ago. I don't remember much, but even if I remembered - I don't think it would help much here. Most serious discussion goes into technical details that I can't comprehend, but the gist of it goes something like this (and then they go into real complex details): <<<1. Why does atmospheric CO2 rise ? Time and again, some people claim that human activities are only a minor source of atmospheric carbon dioxide (CO2) which is swamped by natural sources. Compared to natural sources, our contribution is small indeed. Yet, the seemingly small human-made or `anthropogenic'input is enough to disturb the delicate balance. "Anthropogenic CO2 is a biogeochemical perturbation of truly geologic proportions" [Sundquist] and has caused a steep rise of atmospheric CO2. The vexing thing is that, in the global carbon cycle, the rising levelof atmospheric CO2 and the human origin of this rise are about the only two things that are known with high certainty. Natural CO2 fluxes into and out of the atmosphere exceed the human contribution by more than an order of magnitude. The sizes of the natural carbon fluxes are only approximately known, because they are much harder to measure than atmospheric CO2 and than the features pointing to a human origin of the CO2 rise. >From its preindustrial level of about 280 ppmv (parts per million by volume) around the year 1800, atmospheric carbon dioxide rose to 315 ppmv in 1958 and to about 358 ppmv in 1994 [Battle] [C.Keeling][Schimel 94, p 43-44]. All the signs are that the CO2 rise is human-made: * Ice cores show that during the past 1000 years until about the year 1800, atmospheric CO2 was fairly stable at levels between 270 and 290 ppmv. The 1994 value of 358 ppmv is higher than any CO2 level observed over the past 220,000 years. In the Vostok and Byrd ice cores, CO2 does not exceed 300 ppmv. A more detailed record from peat suggests a temporary peak of ~315 ppmv about 4,700 years ago, but this needs further confirmation. [Figge, figure 3] [Schimel 94,p 44-45] [White] * The rise of atmospheric CO2 closely parallels the emissions history from fossil fuels and land use changes [Schimel 94, p 46-47].