Global Warming: A Sudden Change
of State
http://www.commondreams.org/archive/2007/07/03/2269/
|
Reading a scientific paper
on the train this weekend, I found, to my amazement, that my hands
were shaking. This has never happened to me before, but nor have
I ever read anything like it. Published by a team led by James Hansen
at NASA, it suggests that the grim reports issued by the Intergovernmental
Panel on Climate Change could be absurdly optimistic(1). The IPCC predicts that
sea levels could rise by as much as 59cm this century(2). Hansen's
paper argues that the slow melting of ice sheets the panel expects
doesn't fit the data. The geological record suggests that ice at
the poles does not melt in a gradual and linear fashion, but flips
suddenly from one state to another. When temperatures increased
to 2-3 degrees above today's level 3.5 million years ago, sea levels
rose not by 59 centimeters but by 25 meters. The ice responded immediately
to changes in temperature(3). We now have a pretty good
idea of why ice sheets collapse. The buttresses that prevent them
from sliding into the sea break up; meltwater trickles down to their
base, causing them suddenly to slip; and pools of water form on
the surface, making the ice darker so that it absorbs more heat.
These processes are already taking place in Greenland and West Antarctica. Rather than taking thousands
of years to melt, as the IPCC predicts, Hansen and his team find
it "implausible" that the expected warming before 2100
"would permit a West Antarctic ice sheet of present size to
survive even for a century." As well as drowning most of the
world's centers of population, a sudden disintegration could lead
to much higher rises in global temperature, because less ice means
less heat reflected back into space. The new paper suggests that
the temperature could therefore be twice as sensitive to rising
greenhouse gases than the IPCC assumes. "Civilization developed,"
Hansen writes, "during a period of unusual climate stability,
the Holocene, now almost 12,000 years in duration. That period is
about to end."(4) I looked up from the paper,
almost expecting to see crowds stampeding through the streets. I
saw people chatting outside a riverside pub. The other passengers
on the train snoozed over their newspapers or played on their mobile
phones. Unaware of the causes of our good fortune, blissfully detached
from their likely termination, we drift into catastrophe. Or we are led there. A
good source tells me that the British government is well aware that
its target for cutting carbon emissions - 60% by 2050 - is too little,
too late, but that it will go no further for one reason: it fears
losing the support of the Confederation of British Industry. Why
this body is allowed to keep holding a gun to our heads has never
been explained, but Gordon Brown has just appointed Digby Jones,
its former director-general, as a minister in the department responsible
for energy policy. I don't remember voting for him. There could
be no clearer signal that the public interest is being drowned by
corporate power. The government's energy
program, partly as a result, is characterized by a complete absence
of vision. You can see this most clearly when you examine its plans
for renewables. The EU has set a target for 20% of all energy in
the member states to come from renewable sources by 2020. This in
itself is pathetic. But the government refuses to adopt it(5): instead
it proposes that 20% of our electricity (just part of our total
energy use) should come from renewable power by that date. Even
this is not a target, just an "aspiration", and it is
on course to miss it. Worse still, it has no idea what happens after
that. Last week I asked whether it has commissioned any research
to discover how much more electricity we could generate from renewable
sources. It has not(6). It's a critical question,
whose answer - if its results were applied globally - could determine
whether or not the planetary "albedo flip" that Hansen
predicts takes place. There has been remarkably little investigation
of this issue. Until recently I guessed that the maximum contribution
from renewables would be something like 50%: beyond that point the
difficulties of storing electricity and balancing the grid could
become overwhelming. But three papers now suggest that we could
go much further. Last year, the German
government published a study of the effects of linking the electricity
networks of all the countries in Europe and connecting them to North
Africa and Iceland with high voltage direct current cables(7). This
would open up a much greater variety of renewable power sources.
Every country in the network would then be able to rely on stable
and predictable supplies from elsewhere: hydroelectricity in Scandanavia
and the Alps, geothermal energy in Iceland and vast solar thermal
farms in the Sahara. By spreading the demand across a much wider
network, it suggests that 80% of Europe's electricity could be produced
from renewable power without any greater risk of blackouts or flickers. At about the same time,
Mark Barrett at University College London published a preliminary
study looking mainly at ways of altering the pattern of demand for
electricity to match the variable supply from wind and waves and
tidal power(8). At about twice the current price, he found that
we might be able to produce as much as 95% of our electricity from
renewable sources without causing interruptions in the power supply. Now a new study by the
Center for Alternative Technology takes this even further(9). It
is due to be published next week, but I have been allowed a preview.
It is remarkable in two respects: it suggests that by 2027 we could
produce 100% of our electricity without the use of fossil fuels
or nuclear power, and that we could do so while almost tripling
its supply: our heating systems (using electricity to drive heat
pumps) and our transport systems could be mostly powered by it.
It relies on a great expansion of electricity storage: building
new hydroelectric reservoirs into which water can be pumped when
electricity is abundant, constructing giant vanadium flow batteries
and linking electric cars up to the grid when they are parked, using
their batteries to meet fluctuations in demand. It contains some
optimistic technical assumptions, but also a very pessimistic one:
that the UK relies entirely on its own energy supplies. If the German
proposal were to be combined with these ideas, we could begin to
see how we might reliably move towards a world without fossil fuels. If Hansen is correct,
to avert the meltdown that brings the Holocene to an end we require
a response on this scale: a sort of political "albedo flip".
The government must immediately commission studies to discover how
much of our energy could be produced without fossil fuels, set that
as its target then turn the economy round to meet it. But a power
shift like this cannot take place without a power shift of another
kind: we need a government which fears planetary meltdown more than
it fears the CBI. George Monbiot's book Heat: How to Stop The Planet Burning is now published in paperback. www.monbiot.com ----------------------------------------------------------------------- References: 1. James Hansen et al, 2007. Climate Change and
Trace Gases. Philiosophical Transactions of the Royal Society -
A. Vol 365, pp 1925-1954. doi: 10.1098/rsta.2007.2052. 2. Intergovernmental Panel on Climate Change,
February 2007. Climate Change 2007: The Physical Science Basis -
Summary for Policymakers. Table SPM-3. http://www.ipcc.ch/SPM2feb07.pdf 3. I am grateful to Marc Hudson for drawing my
attention to this paper and giving me a copy. 4. James Hansen et al, ibid. 5. In the Energy White Paper it says the following:
"The 20% renewables target is an ambitious goal representing
a large increase in Member States' renewables capacity. It will
need to be taken forward in the context of the overall EU greenhouse
gas target. Latest data shows that the current share of renewables
in the UK's total energy mix is around 2% and for the EU as a whole
around 6%. Projections indicate that by
2020, on the basis of existing policies, renewables would contribute
around 5% of the UK's consumption and are unlikely to exceed 10%
of the EU's." Department of Trade and Industry, May 2007. Meeting
the Energy Challenge: A White Paper on Energy, page 23. http://www.dtistats.net/ewp/ewp_full.pdf 6. Emails from David Meechan, press officer,
Renewables, Department for Business, Enterprise and Regulatory Reform. 7. German Aerospace Center (DLR) Institute of
Technical Thermodynamics Section Systems Analysis and Technology
Assessment, June 2006. Trans-Mediterranean Interconnection for Concentrating
Solar Power. Federal Ministry for the Environment, Nature Conservation
and Nuclear Safety, Germany. http://www.dlr.de/tt/Portaldata/41/Resources/dokumente/institut/system/ 8. Mark Barrett, April 2006. A Renewable Electricity
System for the UK: A Response to the 2006 Energy Review. UCL Bartlett
School Of Graduate Studies - Complex Built Environment Systems Group.
http://www.cbes.ucl.ac.uk/projects/energyreview/ 9. Center for Alternative Technology, 10th July
2007. ZeroCarbonBritain: an alternative energy strategy. This will
be made available at www.zerocarbonbritain.com. ----------------------------------------------------------------------- |