Re: [asa] CO2 content

Thanks to Rich, Keith, Randy. I appreciate the quick responses.

Burgy

On 8/24/08, Keith Miller <kbmill@ksu.edu> wrote:
> Burgy:
>
>> Attached is a chart showing CO2 content over time.
>>
>> The claim is that this shows rising CO2 is not a problem.
>>
>> What is the rebuttal to this claim?
>
> I addressed the geologic context of global climate change in my talk
> at the ASA meeting this year. An audio of my presentation and the PP
> slides can be obtained at the ASA website.
>
> We are currently in an "ice house" global climate, the other major
> "Ice house" was during the late Carboniferous and early Permian
> Periods. These were both times of historically low CO2 levels and
> continental glaciation ("ice ages"). There have been times in
> geologic history in which the CO2 levels have been much higher than
> at present. In early Earth history, very high levels of methane and
> CO2 were compensated by lower solar irradiance. During the
> Phanerozoic, greenhouse climates have existed during which the poles
> were ice free with forests above the arctic and antarctic circles.
> Significantly, times of very rapid warming associated with elevated
> CO2 levels have been associated with times of mass extinction. The
> greatest extinction in Earth history at the end of the Permian (when
> over 90% of species are estimated to have gone extinct) was likely
> the result of a runaway greenhouse.
>
> The current release of greenhouse gases by the burning of fossil
> fuels is without question a major contributor to the current
> increases in global average temperatures. What is unique about the
> climate change now occurring is not the magnitude of change (from a
> long-term geologic perspective) but that it is being significantly
> caused by us. Furthermore, such increases in global temperature have
> not occurred since modern humans have been on Earth. The current CO2
> levels and global temperature rise has not occurred for over 400,000
> years. Human populations, particularly the poor and those already
> living at the margins economically or environmentally, will be
> significantly affected.
>
> Feedback mechanisms and rapid carbon storage and release have the
> potential to generate very rapid changes in global climate that would
> outstrip the ability of species and ecosystems to adapt, and pose
> serious challenges to human populations. These feedback mechanisms
> pose a real danger if our release of greenhouse gases continues
> unabated. Should we pass a tipping point for these feedbacks, we
> could lose the ability to change course. We must take immediate
> action to reduce our production of greenhouse gases to avoid such an
> outcome. The most practical and immediately effective thing we can
> do is energy conservation. Unfortunately there is great resistance
> to the lifestyle changes that this will require. We also must make a
> focused and deliberate effort to move away from use of fossil fuels
> (we are already at or near peak oil production anyway). The
> technology largely exists for making a significant change in our
> energy use -- the political and social will does not.
>
> The scientific consensus on the issue of human-caused global climate
> change is extremely strong and broad. The reports of the
> International Panel on Climate Change are to my knowledge the most
> extensively reviewed and supported scientific documents ever
> written. They are freely available on the web. Far from being
> extremist, they are very conservative documents and their predictions
> have consistently underestimated observed changes.
>
> Keith
>
>
>
> Keith B. Miller
> Research Assistant Professor
> Dept of Geology, Kansas State University
> Manhattan, KS 66506-3201
> 785-532-2250
> http://www-personal.ksu.edu/~kbmill/
>
>

-- 
Burgy
www.burgy.50megs.com
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