The debate over global warming is getting rancorous
“THE intermixing of science and politics is a bad combination, with a bad history.” So warns
Michael Crichton at the end of his current, popular novel, “State of Fear”. He
argues that wilful obfuscation by politicians and wild-eyed greens is leading to
a herd mentality over global warming, akin to the uncritical embrace of eugenics
a century ago. “Once again,” he intones ominously, “critics are few and harshly
dealt with.”
At first blush, it appears that Dr Crichton might have a point. Of course, there was once an
intense global debate over global warming's most sacred cow—the Kyoto protocol
on climate change. The treaty calls for immediate reductions in emissions of
greenhouse gases by industrialised countries. George Bush upset many greens by
abruptly confirming in 2001 that America would never ratify the Kyoto treaty.
But other countries did ratify it, and it is due to come into full force for
them on February 16th, so the Kyoto debate is over.
The concern about crusading politicians also seems relevant. Tony Blair, Britain's prime
minister, says climate change is his top priority, along with Africa, this year.
He asked Sir David King, his chief science adviser, to organise a scientific
conference in Britain this week to work out what adds up to “dangerous
interference” with the climate system. The conference had not ended as The
Economist went to press, but there was talk of pressure from politicians for
agreement on a specific numerical definition of what is “dangerous”—a notion
some participants said was not justified by the science.
They said,
they said
Despite Kyoto's coming into force, vigorous debate between and among climate sceptics and
climate hawks continues. First, consider the ongoing haggling over the science.
The Intergovernmental Panel on Climate Change (IPCC), a body of leading
scientists which advises the UN on climate issues, has established that the
Earth is indeed warming, thanks in part to man's burning of fossil fuels.
However, questions still remain as to the particulars.
For example, when Kevin Trenberth, head of the IPCC's panel on hurricanes, recently suggested
that there exists a link between climate change and the wave of powerful
hurricanes last year, he was immediately challenged. Christopher Landsea, a
hurricane expert at America's National Oceanic and Atmospheric Administration,
resigned from the IPCC panel, arguing that Dr Trenberth's comments went beyond
what the peer-reviewed science could justify. He wrote a public letter
complaining that: “because of Dr Trenberth's pronouncements, the IPCC process
has been subverted and compromised, its neutrality lost.”
Dr Trenberth retorts that “politics is very strong in what is going on, but it is all coming
from Landsea and colleagues. He is linked to the sceptics.” He explains the
remarks in question by saying that he did not suggest climate change was
affecting the number of hurricanes, but was affecting their intensity, because
of hotter ocean temperatures, a conclusion he says the data readily bears out.
Another example is the controversy over the most important totem of global warming: the “hockey
stick”. That is the nickname given to the plot of global temperatures published
by Michael Mann, then of the University of Massachusetts in Amherst, and his
colleagues in 1998, which shows a sharp upturn beginning at the time of the
industrial revolution. This chart has often been trotted out as the clinching
proof of anthropogenic warming. Sceptics have never liked this chart, which
necessarily relies on statistics to infer historical temperatures from tree
rings.
Two critics, Stephen McIntyre of the Northwest Exploration Company, in Toronto, and Ross
McKitrick of the University of Guelph, also in Ontario, are about to publish a
paper in Geophysical Research Letters (GRL), which alleges that Dr Mann's
statistics are inaccurate, and that the hockey stick is a mere statistical
artefact. Dr Mann and many other climate scientists dismiss Mr McIntrye's and Dr
McKitrick's arguments.
The statistical issues involved are complicated—even Stephen Mackwell, the editor-in-chief of
GRL, which also published some of Dr Mann's earlier papers (along with Nature),
admits that he does not understand the details of the new paper.
The debate over the economics of warming is, if such a thing were possible, even more robust
than the one over the science. The IPCC has come under attack for its scenarios
of future growth. One chief sin is the reliance by IPCC modellers on
market-based exchange rates instead of purchasing-power parity, which adjust
wealth according to domestic purchasing power—which many economists believe is
more accurate. That, says David Henderson, an economist at London's Westminster
Business School, leads to unrealistic projections for economic growth and
therefore emissions growth. He and Ian Castles provided the IPCC with detailed
critiques.
Did the IPCC welcome the chance to improve its projections? Initially, it most certainly did
not. Dr Henderson was frustrated by that reaction. However, he was encouraged to
learn this week that serious economists were cloistered away at a recent meeting
studying ways of incorporating his critiques into the IPCC modelling process.
Whether any substantive changes will emerge remains unclear, but a proper
re-think may be in the works.
Disagreements are also breaking out among those economists relatively sceptical about the
effects of climate change. The Copenhagen Consensus, a project led by Bjorn
Lomborg, a professor at the University of Aarhus, in Denmark, and publicised by
this newspaper, made something of a splash a few months ago by ranking climate
change at the bottom of a list of pressing global problems (see articles).
A panel of eminent economists, among them three Nobel prize-winners, placed
initiatives to tackle HIV/AIDS, malaria, sanitation and other problems
confronting the world's poor ahead of proposals to tackle global warming, which
were described as “bad” investments compared with those aimed at tackling these
other problems. But several participants now say that there was confusion about
how they were ranking ways to spend development aid, or ranking which general
global problems should be tackled.
Of course, greens howled in protest at the dismissal of climate change, and pointed to some
sort of stitch up: after all, some argued, Dr Lomborg is well known for his
opposition to the Kyoto treaty. He rejects such claims, insisting that the
effort was in good faith. He points out that the man selected to write the
“expert paper” on climate, William Cline of the Centre for Global Development, a
think-tank based in Washington, DC, has impeccable credentials; indeed, he is
known as an advocate of forceful, early action to slow global warming. Dr
Lomborg explains that the proposals on climate change fared poorly because they
offered the lowest benefits for the costs incurred.
Now, some members of the Consensus are dissenting. Thomas Schelling of the University of
Maryland, who voted on the final choices, thinks that presenting climate change
at the bottom of the list as “bad” is misleading. He says he and the other gurus
did not like Kyoto or the aggressive proposals made by Dr Cline, whom he sees as
the “most alarmist of the serious climate policy experts”, but Dr Schelling says
he would have ranked modest climate proposals higher on the list, because he
sees climate as a real problem. Robert Mendelsohn, a conservative Yale economist
who was an official “critic” of the climate paper in this process, goes further:
because Dr Cline's positions are “well out of the mainstream”, he had no choice
but to reject them. He worries that “climate change was set up to fail.”
Dr Lomborg insists that that was not at all the case. Picking an enthusiast like Dr Cline
also could suggest that climate was being taken seriously by the Copenhagen
process. However, he accepts that more modest proposals (such as a small carbon
tax or investments in research) would have ranked higher on the list. Dr Cline,
for his part, acknowledges that his views (for example, on the right discount
rates to use when pondering long-term policies) “have not yet been accepted by
the mainstream.” He is unhappy with how climate has been portrayed by the
Copenhagen process, but he still feels that the attempt to assess global
problems was well intentioned and worthwhile.
The death of environmentalism?
Perhaps the clearest sign that the imminent arrival into force of Kyoto has not led to about of green triumphalism comes from the debate among America's greens today.
Michael Shellenberger and Ted Nordhaus, political strategists and green
organisers, argue in a recent policy paper that, judging from polling data,
America's big environmental groups have failed to persuade most Americans. They
argue that greens need to develop more convincing arguments to get Americans to
take global warming more seriously.
Predictably, Messrs Shellenberger and Nordhaus have unleashed a stream of counter-attacks
that have led to a lively debate among American environmentalists. They
conclude: “We in the environmental community today find ourselves head-down and
knee-deep in the global warming river. It's time we got back to shore and
envisioned a new path for the crossing.” Despite the arrival of Kyoto, the
debate and dissent of recent weeks suggests that the treaty has not produced the
world of self-confident greens and smothered critics feared by Dr Crichton. In
fact, the contrary seems to be true.
