[Reader-list] Fwd: Carbon dioxide in Atmosphere

[Ravi Agarwal]

time to unpack  'good!!'

ravi

On Mon, Jun 22, 2009 at 11:32 AM, Jeebesh <jeebesh at sarai.net> wrote:

> What does this do to our ideas of good life?
>
> Begin forwarded message:
>
> > From: Ananth S <sananth99 at gmail.com>
> > Date: 21 June 2009 7:46:12 PM GMT+05:30
> > To: bemous2007 at gmail.com
> > Subject: Carbon dioxide in Atmosphere
> >
> > 2.1 Million-Year High Measured for Carbon Dioxide in Atmosphere
> > By Jeremy van Loon
> > http://www.bloomberg.com/apps/news?pid=newsarchive&sid=aG5p2kBin538
> > June 18 (Bloomberg) -- Carbon dioxide in the earth’s atmosphere has
> > risen to its highest level in at least 2.1 million years, according
> > to a new investigation of the greenhouse gas’s role in ice ages over
> > the millennia.
> >
> > Researchers including Columbia University’s Baerbel Hoenisch drilled
> > into the ocean floor off the coast of Africa to remove shells of
> > ancient marine animals called foraminifera that contain climate
> > records, according to the study published today on Science’s Web
> > site. Previous evidence of CO2 concentrations found in columns of
> > Arctic ice go back just 800,000 years.
> >
> > Carbon dioxide, which traps heat close to earth, is the main
> > contributor to global warming, threatening to raise sea levels and
> > disrupt food production and water supplies, United Nations
> > scientists have said. The marine sediment indicated “stable” levels
> > of atmospheric CO2 at less than 250 molecules per million molecules
> > of air, compared with about 385 today.
> >
> > “What’s remarkable is how little CO2 concentration changed in the
> > past,” said Jerry McManus, a paleoclimatology professor at Columbia
> > who participated in the study. “What we’re seeing now is the same
> > magnitude of natural variations happening in only a few decades.”
> >
> > The CO2 concentration ranged between 181 and 297 parts per million
> > over the period studied. It may be necessary to go back as far as
> > 2.7 million years to find levels of CO2 similar to today’s, the
> > study concluded, without attributing reasons for previous surges.
> >
> > Carbon Spike
> >
> > If the world continues to burn coal and oil and cut down forests
> > that store carbon, the amount of CO2 in the atmosphere may more than
> > double to 900 parts per million in the next century, the UN’s
> > Environment Programme Executive Director Achim Steiner has said.
> >
> > Negotiators at UN-sponsored talks are attempting to set limits on
> > CO2 emissions. Delegates are focused on restricting output of the
> > gas, which has grown 2 percent since industrialization in the 1800s,
> > to 450 parts per million and slowing the rise in average global
> > temperature to 2 degrees Celsius (3.6 Fahrenheit) over the next
> > century.
> >
> > “With unabated emissions, many trends in climate will likely
> > accelerate, leading to an increasing risk of abrupt or irreversible
> > climatic shifts,” 10 universities said today in a report suggesting
> > that climate change was underestimated.
> >
> > The United Nations Intergovernmental Panel on Climate Change in 2007
> > blamed global warming on emissions of such gases and warned of
> > increased flooding and drought as temperatures continue to rise.
> > Greenhouse gases also include water vapor, methane and nitrous oxide.
> >
> > ‘Unprecedented’
> >
> > The study published in Science today “is the best existing record so
> > far that shows atmospheric concentrations of carbon dioxide,” said
> > Columbia’s McManus. “It strengthens the case that this is fairly
> > unprecedented” for an increase in CO2.
> >
> > Other evidence of greenhouse gas concentration has been discovered
> > in ice. Polar researchers reported last year in the journal Nature
> > that carbon dioxide was at an 800,000-year high, after studying
> > bubbles trapped in ice drilled from the Antarctic.
> >
> > Hoenisch and colleagues investigated the role of the carbon cycle in
> > climate change and concluded that CO2 was probably not responsible
> > for lengthening the time between major ice ages to 100,000 years
> > from 40,000, countering a supposition that massive ice sheets grew
> > and receded because of gradually decreasing levels of carbon dioxide.
> >
> > Even with the likelihood of the earth warming up in the coming
> > centuries, we’re headed for another ice age at some point thousands
> > of years in the future, said McManus.
> >
> > “The earth is moving into an increasingly glaciated state,” he said.
> > “It’s just that the intervals between ice ages, which we’re living
> > in now, have become longer and warmer.”
> >
>
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