Re: [asa] climate change severity

Seems Janice is once again trivializing the science behind the human
component to CO2. Perhaps cows are more damaging than cars when it
comes to CO2, but cars make up a small amount of human CO2 emissions.

We all at risk to ridicule that which we don't understand...

Will she ever learn from Augustine?...

On 1/4/07, Janice Matchett <janmatch@earthlink.net> wrote:
>
> At 12:42 PM 1/4/2007, Charles Carrigan wrote:
>
> Don,
>
> Human beings began pumping CO2 into the atmosphere well before 1930. I
> understand wanting to be skeptical of bandwagons, but the data that indicate
> human impact are pretty strong. Natural warming may also be occurring, but
> the data clearly show a massive anthropogenic involvement.
>
> Ice core measurements indicate that in the year ~1800, the concentration of
> CO2 in the atmosphere was down near 275 ppm, but steadily rising over the
> next 100 years to reach ~300 ppm by 1900. Direct measurement of
> atomospheric CO2 goes back to the late 1950s, when the value was up to ~315
> ppm; today it is near ~375 ppm. Although we've certainly done much more in
> the past 50 years, humans did plenty between 1800 and 1930.
>
> To put it in natural context - in the deep geologic record, CO2 has
> fluctuated in the atmosphere between ~180-280 ppm over the last at least
> 400,000 years, and I believe the record now goes back even further to the
> past 650 ka; at no point in that history has CO2 reached the levels it is at
> today, or even the levels it was at in 1950. The concentration of CO2 in
> past atmospheres is measured by trapped gas bubbles in deep ice cores from
> Antarctica. There is a tremendous inverse correlation between times of low
> CO2 (~180 ppm) and large amounts of continental ice as interpreted by
> delta18O data (stable isotopes of H2O), and also the reverse - times of high
> CO2 (~280 ppm) correlate with times of low continental ice. This obviously
> fits with the notion that CO2 is a greenhouse gas.
>
> A couple of references:
> Petit, J.R., et al., 1999, Climate and Atmospheric History of the Past
> 420,000 Years from the Vostok Ice Core, Antarctica. Nature, 399, 429-436.
> Friedli et al., 1986, Ice Core Record of the 13C/12C Ratio of Atmospheric
> CO2 in the Past Two Centuries. Nature, 324, 237-238
>
> There is no question that human beings over the past 200 years have
> dramatically altered the concentration of CO2 in Earth's atmosphere. There
> is also a clear connection between CO2 concentration and global T.
>
> Best,
> Charles
>
> @ I see you didn't get the memo.
> http://cagle.msnbc.com/working/061213/lester.jpg
>
> ~ Janice
>
>
>

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Received on Fri Jan 5 01:04:00 2007