Hello All,
Thanks again to Alvia for unearthing another thought-provoking article.
The following will (I hope) already be known to most readers of this
blog, but in case there are interested others I'd like to correct some
of the statements made in the article regarding our
cloud-albedo-enhancement geoengineering idea:-
1. The idea is not recent. It was first proposed almost 20 years ago:
"Latham, J. 1990 Control of global warming? Nature 347, 339-340",
since which time 5 other peer-reviewed papers have been written on it,
most recently two in the special geo-engineering issue of "Phil Trans.
Roy. Soc.", 2008. Ancient would be a more accurate word than recent,
unfortunately.
2. The idea is not "theoretical only". One of our Phil Trans papers
cites 3 experimental/observational papers (not by us), all published
in 2008, two involving global satellite measurements, one atmospheric
airborne studies, all providing significant quantitative support for
the scheme.
3. "Bombarding" is possibly an excessively violent term to describe
the slow drift of sub-micrometre seawater particles into the bases of
maritime stratocumulus clouds; which is what we propose.
Cheers, John. [EMAIL PROTECTED]
***********************
Quoting "Alvia Gaskill" <[EMAIL PROTECTED]>:
> http://www.cyprus-mail.com/news/main.php?id=41867&cat_id=9
>
> Extraordinary ideas for extraordinary circumstances
> By Elias Hazou
>
> A NOBEL Prize-winning scientist has drawn up an emergency plan to
> save the world from global warming, by altering the chemical makeup
> of Earth’s upper atmosphere. Professor Paul Crutzen, who won a Noble
> Prize in 1995 for his work on the destruction of the ozone layer,
> believes that political attempts to limit man-made greenhouse gases
> are so pitiful that a radical alternative is needed.
>
> The Netherlands-born professor was on the island this week for a
> workshop on “Climate change: causes and impacts” organised by the
> Cyprus Institute, a research foundation.
>
> In a polemical scientific essay published two years ago, Crutzen
> suggested an “escape route” if global warming begins to run out of
> control.
>
> He has proposed a method of artificially cooling the global climate
> by releasing particles of sulphur in the upper atmosphere, which
> would reflect sunlight and heat [Doesn't reflect IR. AG] back into
> space.
>
> A fleet of high-altitude balloons could be used to scatter the
> sulphur high overhead, or it could even be fired into the atmosphere
> using heavy artillery shells or rockets [Too costly and/or
> infeasible. AG], said Professor Crutzen, a researcher at the Max
> Planck Institute for Chemistry in Germany.
>
> “It’s the last resort. Unless CO2 emissions are cut - and the
> outlook is very grim - I’m afraid we shall have resort to this
> experiment,” Crutzen told the Sunday Mail in an interview.
>
> For the experiment to work, a million tons of sulphur would have to
> be injected every year into the stratosphere, 16 km above the earth.
> [Not high enough. AG]
>
> “Right now, chimneys spew out 10 times more sulphur into the lower
> atmosphere every year,” Crutzen said, addressing concerns about the
> side effects.
>
> His plan is modelled partly on the Mount Pinatubo volcanic eruption
> in 1991, when thousands of tons of sulphur were ejected into the
> atmosphere causing global temperatures to fall.
>
> Pinatubo generated sulphate aerosols in the atmosphere which cooled
> the Earth by 0.5C on average in the following year. The sulphate
> particles did this by acting like tiny mirrors, preventing a portion
> of incoming sunlight from reaching the ground.
>
> Although climate cooling by sulphate aerosols also occurs in the
> troposphere, Crutzen says the great advantage of placing reflective
> particles in the stratosphere is their long residence time of about
> one to two years, compared to a week in the troposphere. The
> chemical would also need to have a short half-life, say 10 years
> [What chemical is that, something other than sulfuric acid? Must
> have been referring to his other idea to develop a chemical that
> wouldn't have adverse impacts on ozone. AG.]
>
> The professor admits the idea is extreme, but says extraordinary
> measures are necessary in extraordinary circumstances.
>
> “I hope we never have to do this experiment. But for CO2 levels to
> get back to normal, current emissions would need to drop by about 60
> to 80 per cent. I don’t see that happening.” [Then we have to do
> it, right? AG]
>
> CO2 emissions, released by the burning of fossil fuels in power
> stations, factories, homes and vehicles, are growing at almost three
> per cent a year. [Thanks to Bush and his buddies, to soon be
> reduced for a while. AG]
>
> The United Nations Panel on Climate Change estimates that world
> temperatures may rise by between 1.8 and 4 degrees Celsius (3.2-7.2
> degrees Fahrenheit) this century. The Group of Eight industrial
> nations agreed in July to a goal of halving world emissions by 2050.
>
> Assuming Crutzen’s idea is feasible, it would cost some $10 billion
> a year to spray the upper atmosphere with enough sulphur. [A more
> realistic estimate than the $50 billion in his paper that keeps
> getting quoted. AG]
>
> “But this is peanuts.” He pauses. “Especially if you compare it with
> the enormous sums of money mentioned in the international credit
> crisis.”
>
> Other 'geo-engineering' ideas include deploying giant unfolding
> mirrors in space, laying reflecting film in the deserts, or floating
> white plastic islands in the ocean to mimic the reflective effect
> of sea ice. Boosting the population of marine plankton, which
> absorb carbon dioxide from the atmosphere, is another thought.
>
> More recently, scientists have considered bombarding clouds with
> salt to produce a similar reflective effect - this is still at the
> theoretical stage, although experiments on a small scale are not
> that far away.
>
> Crutzen says he was under “a lot of pressure from many circles” not
> to air his idea two years ago.
>
> Some scientists had even opposed its publication in the
> peer-reviewed scientific press. There was concern that it may
> encourage the view that a quick fix to climate change was preferable
> to addressing the causes of the phenomenon. [Those people are still
> around. AG]
>
> Crutzen is well aware of this point, which is why in his essay he
> also points out that the possibility of the sulphur experiment
> “should not be used to justify inadequate climate policies, but
> merely to create a possibility to combat potentially drastic climate
> heating.”
>
> He told the Sunday Mail that much of the initial brouhaha generated
> by his proposal has since died down, and the idea is now being taken
> seriously by a number of researchers, including at the US National
> Centre for Atmospheric Studies and Rutgers University.
>
> Far from being dogmatic, Crutzer says he will be the first to admit
> he’s wrong if experiments show the idea is dangerous or unfeasible.
>
> “It’s not my baby,” he said, mimicking a cradling motion.
>
>
>
>
>
> Copyright © Cyprus Mail 2008
> >
>
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