By Achim
Steiner
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Nairobi, 5 February 2010 - The science of
climate change has been on the defensive
in recent weeks, owing to an error that
dramatically overstated the rate at which
the Himalayan glaciers could disappear.
Some in the media, and
those who are skeptical about climate change,
are currently having a field day, parsing
every comma and cough in the Intergovernmental
Panel on Climate Change's (IPCC) 2007 assessment.
Some strident voices
are even dismissing climate change as a
hoax on a par with the Y2K computer bug.
As a result, the public
has become increasingly bewildered as the
unremitting questioning of the IPCC and
its chair assumes almost witch-hunting proportions
in some quarters.
The time has really
come for a reality check. It is quite right
to pinpoint errors, make corrections, and
check and re-check sources for accuracy
and credibility. It is also right that the
IPCC has acknowledged the need for ever
more stringent and transparent quality-control
procedures to minimize any such risks in
future reports.
But let us also put
aside the myth that the science of climate
change is holed below the water line and
is sinking fast on a sea of falsehoods.
Over the course of 22
years, the IPCC has drawn upon the expertise
of thousands of the best scientific minds,
nominated by their own governments, in order
to make sense of the complexity of unfolding
environmental events and their potential
impacts on economies and societies.
The Panel has striven
to deliver the "perfect" product
in terms of its mandate, scientific rigor,
peer review, and openness, and has brought
forward the knowledge – but also the knowledge
gaps – in terms of our understanding of
global warming.
Its 2007 report represents
the best possible risk assessment available,
notwithstanding an error – or, more precisely,
a typographical error – in its statement
of Himalayan glacial melt rates.
One notion promulgated
in recent weeks is that the IPCC is sensationalist:
this is perhaps the most astonishing, if
not risible claim of all.
Indeed, the Panel has
more often been criticized for being far
too conservative in its projections of,
for example, the likely sea-level rise in
the twenty-first century.
Indeed, caution rather
than sensation has been the Panel's watchword
throughout its existence.
In its first assessment,
in 11000, the IPCC commented that observed
temperature increases were "broadly
consistent with predictions of climate models,
but it is also of the same magnitude as
natural climate variability."
The second assessment,
in 1995, said: "Results indicate that
the observed trend in global mean temperature
over the past 100 years is unlikely to be
entirely natural in origin."
In 2001, its third assessment
reported: "There is new and stronger
evidence that most of the warming observed
over the last 50 years is attributable to
human activities."
By 2007, the consensus
had reached "very high confidence"
– at least a 90% chance of being correct
– in scientists' understanding of how human
activities are causing the world to become
warmer.
This does not sound
like a partial or proselytizing body, but
one that has striven to assemble, order,
and make sense of a rapidly evolving scientific
puzzle for which new pieces emerge almost
daily while others remain to be found.
So perhaps the real
issue that is being overlooked is this:
confronted by the growing realization that
humanity has become a significant driver
of changes to our planet, the IPCC, since
its inception, has been in a race against
time.
The overwhelming evidence
now indicates that greenhouse-gas emissions
need to peak within the next decade if we
are to have any reasonable chance of keeping
the global rise in temperature down to manageable
levels. Any delay may generate environmental
and economic risks of a magnitude that proves
impossible to handle.
The fact is that the
world would have to make a transition to
a low-carbon, resource-efficient future
even if there were no climate change.
With the world's human
population set to rise from six billion
to nine billion people in the next half-century,
we need to improve management of our atmosphere,
air, lands, soils, and oceans anyway.
Rather than undermine
the IPCC's work, we should renew and re-double
our efforts to support its mammoth task
in assembling the science and knowledge
for its fifth assessment in 2014. What is
needed is an urgent international response
to the multiple challenges of energy security,
air pollution, natural-resource management,
and climate change.
The IPCC is as fallible
as the human beings that comprise it. But
it remains without doubt the best and most
solid foundation we have for a community
of more than 190 nations to make these most
critical current and future global choices.
Achim Steiner is Executive Director of the
United Nations Environment Programme, which
co-hosts the IPCC.