[NYTr] Can science really save the world?

[All the News That Doesn't Fit]

The Observer - Oct 7, 2007
http://observer.guardian.co.uk/focus/story/0,,2185343,00.html

Can science really save the world?

Endless treaties to cut carbon emissions and halt global warming have
failed to turn the tide of pollution. Now scientists want to intervene
on a planetary scale, changing the very nature of our seas and skies.
Ahead of a major report on 'geo-engineering' we reveal the six big
ideas that could change the face of the Earth

by Robin McKie and Juliette Jowit

They are the ultimate technological fixes: schemes that will span our
planet and involve scientists in reshaping our world to save it from
global warming. Yet only a few years ago, such projects - giant space
mirrors, flotillas of artificial cloud makers and ocean fertilisation
programmes - were dismissed as the stuff of science fiction.

Today many engineers and researchers - fearful of the rate at which our
planet is warming - say geo-engineering projects are now mankind's only
hope of saving itself from the impact of climate change. A major report
and a new exhibition at the Science Museum starting next week will
resurrect the debate.

Despite 10 years of international negotiations aimed at reducing carbon
dioxide levels by between 60-80 per cent, global emissions are still
rising. The only hope, say geo-engineers, is to change the planet, alter
its oceans and reshape its cloud cover.

It is a point highlighted by Brian Launder, professor of mechanical
engineering at Manchester University, who was once 'neutral' about these
great geo-engineering projects but who has come to believethat current
attempts to reduce CO2 emissions are doomed to failure.

'As time has gone on I have become increasingly concerned about the lack
of progress on climate change and [although] they once seemed a last
resort, I have to say we're going to need to do this.'

Launder is now editing a forthcoming issue of the Philosophical
Transactions of the Royal Society which will be devoted to the subject
of geo-engineering schemes. 'We're moving, but I think we need to go a
lot further.'

An exhibition - Can Algae Save The World? - opening at the Science
Museum will also focus on hi-tech projects aimed at saving the planet.

The latest assessment report by the Intergovernmental Panel on Climate
Change, published earlier this year, considered three major techniques
to reduce sunlight reaching the Earth: orbiting mirrors, sulphur
particle schemes and projects for enhancing cloud cover.

The ideas 'could have beneficial consequences' by increasing
agricultural productivity and forestry, the panel concluded. Carbon
dioxide would be left in the atmosphere, stimulating plant growth,
while reductions in sunlight would stop temperatures from rising even
as CO2 levels continued to increase.

'Geo-engineering is one of the types of thing that are worth
investigating,' says Ken Caldeira, of the Carnegie Institution of
Washington. 'If we can generate 100 ideas, and 97 are bad and we land up
with three good ones, then the whole thing will have been worthwhile.'

Opponents to such schemes point out that it is technology that got
mankind in its current fix. An even bigger dose of technology is
therefore the last thing the planet needs. Schemes for fertilising the
oceans with iron compounds pose immense risks to marine life, for
example. Geo-engineers defend their schemes by pointing out that
emissions of greenhouse gases are already bringing huge changes to
natural ecosystems.

It is a point stressed by the distinguished ecologist James Lovelock:
there are dangers in intervening but the risks posed by doing nothing
are worse. 'There may be all sorts of ecological consequences,' he
said. 'But then the stakes are terribly high.'

Ocean pumps

Two of Britain's leading environmental thinkers, Chris Rapley, head of
the Science Museum, and James Lovelock, creator of the Gaia concept,
suggest vertical pipes could pump deep cold water to the sea surface.
Cold ocean water is considered to be more 'productive' than warmer
water because it contains more lifeforms. And these lifeforms are vital
for absorbing CO2.

Using special valves, cold water would be made to flow up floating pipes
and out on to the ocean surface, bringing increased numbers of lifeforms
into contact with the atmosphere and its carbon dioxide. These lifeforms
would absorb CO2, die and then sink to the ocean floor, storing the
carbon away for millennia.

Marine biologists point out that the scheme could pose major problems
for sea life, in particular for creatures such as whales and porpoises.

Chance of success: 3/5 Impact on marine life could count against the
scheme.

Sulphur blanket

During major volcanic eruptions, the Earth often undergoes significant
cooling. For example, when Mount Pinatubo in the Philippines erupted in
1991 the average temperature across the Earth decreased by 0.6C.
Scientists pointed the finger of blame at the 10 million tonnes of
sulphur that the volcano ejected into the stratosphere. So why not copy
Pinatubo? That is the suggestion of Professor Paul Crutzen who won a
Nobel prize in 1995 for his work on the ozone layer.

He has proposed creating a 'blanket' of sulphur that would block the
Sun's rays from reaching Earth; to do this, he envisages hundreds of
rockets filled with sulphur being blasted into the stratosphere. About
one million tonnes of sulphur would be enough to create his cooling
blanket, he says.

The idea alarms other scientists, who fear such a massive input of
sulphur into the upper atmosphere could increase acid rain or damage
the ozone layer. Crutzen believes his idea may still be necessary if
Earth continues to warm up at its current rate. 'I am prepared to lose
some bit of ozone if we can prevent major increases of temperature, say
beyond two degrees or three degrees,' he says.

Chance of success: 1/5 Risks of acid rain and ozone depletion will
provoke opposition.

Mirrors

Radiation from the Sun heats our planet and sustains life here. But as
Earth warms up, scientists want to cut that radiation and one of the
most ambitious ideas involves firing giant mirrors into its orbit.

Physicist Lowell Wood, at the Lawrence Livermore National Laboratory in
California, has put forward the idea of using a mesh of aluminium
threads, a millionth of an inch in diameter. 'It would be like a window
screen made of exceedingly fine metal wire,' he explains. The screen
wouldn't completely block sunlight but would filter infra-red radiation.

However, such mirrors would be expensive to make and put into orbit. To
produce a 1 per cent cut in solar radiation would require mirrors with
surface areas of 600,000 square miles. But once in space such mirrors
would be extremely cheap to operate.

'It's very hi-tech,' said John Shepherd, professor of marine science at
the National Oceanographic Centre at Southampton University. 'Who knows
whether they can really do it? And it's going to cost a lot of money to
find out.'

Chance of success: 1/5 Incredibly expensive.

Cloud shield

John Latham, at the National Centre for Atmospheric Research in
Colorado, and Stephen Salter, of Edinburgh University estimate that
increasing cloud cover using a seawater spray 'seeding' process could
increase cloud cover by 4 per cent - enough to counter a doubling of
carbon dioxide in the atmosphere by shielding Earth from solar
radiation.

Their plan is one of the cheaper ideas for countering rising carbon
dioxide levels and is relatively low-tech, leading to hopes that, if
computer simulations give good results, a field trial could start in
five years.

Latham acknowledges there are dangers in changing weather patterns. 'We
certainly shouldn't implement [it] in any global sense until we've done
our best to examine what implications it might have,' he says.

'But if one felt that there are unlikely to be any implications that are
more severe than the damage global warming is causing, then I think we'd
begin.'

Chance of success: 2/5 Will need major global commitment to succeed.

Synthetic trees

Planting trees that absorb carbon dioxide has become a major
eco-industry. But now scientists are proposing a surprise technological
variant: synthetic trees. These trees would not grow or flower or leaf
- but they would absorb carbon dioxide.

This startling concept is the brainchild of Klaus Lackner of Columbia
University who first outlined his proposal at an annual meeting of the
American Association for the Advancement of Science. He describes his
synthetic trees as looking like 'goal posts with Venetian blinds'.

Lackner has calculated that one of his synthetic trees could remove
about 90,000 tonnes of carbon dioxide in a year - the output of more
than 15,000 cars and a thousandfold improvement on the natural
behaviour of a real, living tree.

Lackner's concept is a variant of carbon sequestration technology which
involves the seizing of carbon and storing it underground. Already
schemes exist for removing carbon dioxide produced by burning coal, gas
or oil at power plants before it reaches the atmosphere. Other projects
are investigating ways to liquefy this carbon dioxide and store it in
old mines or oilfields.

However, the process does not work for all polluters, in particular cars
and lorries - hence Lackner's synthetic trees which would act like
filters, removing carbon dioxide from that atmosphere. An absorbent
coating, such as limewater, on slats would capture carbon dioxide so
that it could be removed and then buried. However, critics say the
scheme suffers from the fact that engineers could end up expending more
energy in capturing carbon dioxide than they would save.

Chance of success: 4/5 Carbon sequestration is likely to play a major
role in the world's battle against climate change, though perhaps not
in the form of synthetic trees.

Forests of the seas

Blooms of plankton and algae are the grasslands and prairies of the
oceans. They absorb carbon dioxide, die and then sink to the seabed
carrying the carbon dioxide they absorbed during their lifetimes.
Increase such blooms and you could take out more and more carbon
dioxide from the atmosphere, scientists argue - an idea that formed the
core of a recent meeting of experts at the Woods Hole Oceanographic
Institution in the US.

The favoured method for stimulating plankton growth is to use iron
fertilisers. It is known that tiny amounts of iron are critical in
stimulating phytoplankton growth in seas. However, in many parts of the
world iron in seawater is virtually non-existent and plankton levels
correspondingly low.

Several groups of US entrepreneurs have begun experiments aimed at
correcting this problem by pumping tonnes of soluble iron compounds into
sea areas. Several trial schemes are now under way. But some critics
warn that very little carbon dioxide would be removed from the
atmosphere this way, while there is a danger such schemes could cause
dangerous pollution.

Chance of success: 2/5 Method already in trials, but faces considerable
opposition over potential damage to marine life.