[extropy-chat] Global warming news

[Martin Striz]

On 3/24/06, "Hal Finney" <hal at finney.org> wrote:

> Today there is some alarming reporting about new studies published
> in Science.  Here is a sample from London's Times:
> http://www.timesonline.co.uk/article/0,,2-2100776,00.html
>
> > London 'under water by 2100' as Antarctica crumbles into the sea
> > By Mark Henderson, Science Correspondent
> >
> > DOZENS of the world's cities, including London and New York, could be
> > flooded by the end of the century, according to research which suggests
> > that global warming will increase sea levels more rapidly than was
> > previously thought.
> >
> > The first study to combine computer models of rising temperatures with
> > records of the ancient climate has indicated that sea levels could rise
> > by up to 20ft (6m) by 2100, placing millions of people at risk.

This is highly speculative.  We can't accurately predict what the
wearther will be in two weeks, let alone climatic changes over 100
years.  But even a few meters would be catastrophic to some coastal
areas.  Some entire island nations, like the Maldives, would cease to
exist.

> > The threat comes from melting ice sheets in Greenland and Antarctica,
> > which scientists behind the research now believe are on track to release
> > vast volumes of water significantly more quickly than older models have
> > predicted. Their analysis of events between 129,000 and 116,000 years
> > ago, when the Arctic last warmed to temperatures forecast for 2100,
> > shows that there could be large rises in sea level.

Even without glacier melting, the thermal expansion of the top strata
of the ocean is estimated to be about 50 cm per centigrade rise in
ocean temperature.

> The Science articles are here: <http://www.sciencemag.org/sciext/ice/> but
> require a subscription.  Here is an excerpt from their editorial:
> http://www.sciencemag.org/cgi/content/summary/311/5768/1673
>
> > A central feature of this long baseline is this: At no time in at
> > least the past 10 million years has the atmospheric concentration
> > of CO2 exceeded the present value of 380 ppmv. At this time in the
> > Miocene, there were no major ice sheets in Greenland, sea level was
> > several meters higher than today's (envision a very skinny Florida),
> > and temperatures were several degrees higher. A more recent point of
> > reference, and the subject of two papers in this issue, is the Eemian:
> > the previous interglacial, about 130,000 to 120,000 years ago. This
> > was a warm climate, comparable to our Holocene, during which sea levels
> > were several meters higher than today's, even though CO2 concentrations
> > remained much lower than today's postindustrial level.
>
> This is highly alarming.  Today's CO2 level of 380 ppm is already
> higher than we have seen in the past 10 million years.  And this level
> is certain to rise no matter what we do.  We will pass 400 very shortly
> and probably pass 500.  Only by the most stringent economic limitations
> and unprecedented international agreements could we stabilize at 500 or
> 550 ppm.
>
> The problem is that it's probably too late.

So why exacerbate the situation?

> As noted above, 380 is
> already higher than what it was when most of Florida was gone.  New York
> and London will flood.  Much of the U.S. Gulf coast will be covered.
> Coastal cities worldwide will be inundated.  That's just based on today's
> CO2 levels.

Luckily water covers 2/3 of the earth's surface and has a high
specific heat, so it will be slow to warm, and it has a tempering
effect over the rest of the earth's surface (otherwise daily
temperature fluctuations would be over hundreds of degrees centigrade,
not 10).  That should slow the overall process.  However, that won't
stop the direct melting of polar ice.  Antarctica is eroding at the
fastest rate on record.

> So what is the solution?  It seems to me that at this point, trying to
> limit CO2 is the wrong answer.  Maybe it could help at the margin but
> it will not fix the problem.  No matter what we do with CO2 limits, all
> those bad things will happen.

It's unclear how severely CO2 levels will impact average global
temperature.  That depends on many contingencies.

> The only solution is to remove the CO2 from the atmosphere.  We have to
> develop the technologies to do this.  Now, I know Extropians will say
> that of course we will have these technologies within a few decades,
> and that CO2 will be the least of our worries.

Sometimes it is almost a religious faith, isn't it?

> Nanotech or even just
> biotech can sequester CO2 at high rates and cleanse the atmosphere within
> a few years once we have the technology.

How long will it take to process a volume of air that is 2 billion
cubic miles (200 million square mile surface x 10 mile elevation)?

> It will require a change from today's fashionable negativity towards
> science specifically and human action in general.

Yes.  If you want to be Proactive, there are lifestyle changes that
you can make right now that can mitigate the severity of the problem.

Cheers,
Martin Striz