Skeptic lobbyists GWPF ‘cherrypick’ IPCC report to ‘make it sound benign’
- 22 Nov 2011, 13:30
- Verity Payne
The Intergovernmental Panel on Climate Change (IPCC) last week
released the
Summary for Policymakers for its latest report - the 'Special
Report for Managing the Risks of Extreme Events and Disasters to
Advance Climate Change Adaptation' (SREX). The report evaluates the
role of climate change in extreme weather events, and discusses how
best to minimise exposure and vulnerability to extreme weather
events.
Media coverage of the report varied considerably. The
Guardian, for example, focused on the conclusion that some
extreme weather events, such as heatwaves and heavy rainfall, have
been happening more frequently as climate has changed over recent
decades, and are expected to increase in coming decades. They
pointed out that the report is less confident about changes in some
other extreme weather events, including tornadoes and tropical
storms.
The BBC's
Richard Black took a similar line, also discussing the
difficulties in attributing specific extreme weather events to
climate, but noting that overall trends in extreme weather events
can be assessed. Black also suggested that the recent scrutiny the
IPCC has received has helped to improve quality control, quoting
Professor Chris Field, Working Group II co-chairman:
"I think that the quality control
procedures that we used in this report were very carefully
constructed and very carefully executed - I feel very good about
the overall level of quality and scrutiny."
On the other hand, the
Australian might have been reading different research. They
majored on uncertainty in the projections in a piece headlined
'Climate change effects unknown: IPCC report'. The article
began
"Great uncertainty remains about how
much of an impact climate change will have on future extreme
weather events".
The effect of this was to imply that, across the board,
scientists don't know how extreme weather will be affected by
climate change. In fact, they have different levels of confidence
about making predictions for different kinds of weather.
So for example the IPCC's review of the scientific literature
says it is "virtually certain" (implying 99 to 100 percent
likelihood) that temperature extremes will increase over the 21st
century, it is "very likely" (implying 90 to 100 percent
likelihood) that heat waves will continue to increase, and it is
also "very likely" that average global sea level rise will
contribute to increasing extreme coastal high water levels.
On the other hand, scientists have less understanding of other
types of extreme weather like
tropical cyclones or changes in drought patterns. The summary
suggests just 'medium' or 'low' confidence that droughts will
intensify over the 21st century, depending on the region.
Cherrypicking uncertainty
The increasingly prominent climate skeptic lobbyists the Global
Warming Policy Foundation (GWPF) wasted no time in offering their
own
interpretation of the SREX report:
"According to a preliminary report
released by the IPCC, there will be no detectable influence of
mankind's influence on the Earth's weather systems for at least
thirty years, and possibly not until the end of this century.
"...Surveying the state of scientific
knowledge IPCC scientists say they cannot determine if mankind's
influence will result in more, or fewer, extreme weather events
over the next thirty years or more."
Notable in the Australian was a quote from GWPF director Benny
Peiser, who ignored the IPCC's more definitive conclusions to
selectively focus on the uncertainty in the scientific predictions
- which they have done
repeatedly in the past.
"Global Warming Policy Foundation
director Benny Peiser said the overall message was 'there was not a
strong empirical link between anthropogenic climate change and
weather events'.
"'It is unlikely there will be one for
20 to 30 years,' he said.
"He said any suggestion that recent
weather events could be directly linked to climate change went
directly against the general scientific consensus."
We asked one of the report's lead authors whether this was a
reasonable interpretation of the report. Professor David
Easterling, Chief of the Scientific Services Division at NOAA's
National Climatic Data Center, told us that the GWPF's take on the
SREX Summary for Policymakers was a "gross
over-simplification".
The SREX report notes that expected changes in some kinds of
weather extremes may be masked by natural climate variability over
the next twenty or thirty years, particularly for things like
tropical cyclones, which don't show clear changes so far.
But it also states that there are other kinds of extreme weather
events like heatwaves and heavy precipitation which have already
increased in length (heatwaves) and frequency (both heatwaves and
heavy precipitation) over recent decades.
Professor Easterling noted that while natural fluctuations in
the climate mean spotting changes in some weather patterns is more
difficult in the short term,
"...For many other [extreme events],
especially temperature-related extremes and heavy precipitation
increases, the signal is already there, so they are cherry picking
to make it sound benign."
Finally, a plea to the IPCC
As noted, the summary report was published on Friday, with the
full report (which the summary, er, summarises) out in February
next year. Perhaps there is a good bureaucratic reason for this
three month gap, but in the modern age of the internet when people
(rightly) want to be able to check the reasoning and sources on
material to the fullest extent possible, this is a practice that
could do with changing.
This is particularly important as the summary documents are
agreed by representatives of governments involved in the IPCC
process. In this context, being able to see the full report becomes
particularly important as it allows consideration of the scientific
material itself. Making the full report available at the same time
as the summary - or publishing the summary after the report is
released, if necessary - would allow more transparent consideration
of the organisation's work.