Muller: “I draw a distinction between skeptics and deniers”
- 07 Nov 2011, 14:00
- Verity Payne
The Berkeley Earth Surface Temperature (BEST) study has been the
subject of an ongoing media saga over the last few weeks.
US physicist Richard Muller took allegations made by climate
skeptics that climatologists had been manipulating the data and
over-estimating global warming seriously. He assembled the
BEST project - partially funded by the Koch brothers - to
address those criticisms and reassess global temperature
trends.
When the project's papers were released a few weeks ago however,
it was revealed the study had found that
global land temperatures have increased by around 1°C over the last
60 years - a finding in line with the temperature reconstructions
from other groups of scientists. The study also found that the
urban heat island effect and poor station quality - touted by
skeptics as invalidating other research groups' temperature
reconstructions - did not bias the results obtained from these
earlier studies.
The skeptic response to the study ranged from swift
backtracking - 'we've never doubted warming' - to an attack by
the
Mail on Sunday on Muller and the BEST study, which relied on a
dubious analyis from a climate skeptic think-tank and
misrepresented BEST co-author Judith Curry.
Muller and the BEST team have also received criticism from both
scientists and
skeptics for releasing the BEST data before peer review.
Now Muller has been interviewed by the journal
Nature Climate Change. The interview provides little new
information about a project that has already been extensively
picked over by a variety of news outlets, but does give us some new
insight into his views - particularly how he views the nature of
climate skepticism.
Most revealing was Muller's response to the question "Do you
think your results will convince sceptics that global warming is
real?":
"I draw a distinction between sceptics
and deniers. The sceptics are people I respect - they have raised
legitimate issues and, from my experience, are open minded. The
deniers are people who start with a conclusion and only pay
attention to the data that support it. I do think that our results
could change the minds of some sceptics about the reality of global
warming."
He also says
"This field [climate science] has been
more contentious than need be because some scientists have confused
the sceptics with the deniers. Scientists were told that sceptics
were anti-science; that this issue was akin to the one over
intelligent design."
It would be interesting to know who exactly Muller is referring
to here. It is undoubtedly true that prominent climate skeptics
routinely rubbish the science of climate change (see for example here, here
and
here). This has
included the skeptic blog Watts Up With That, who
Muller was previously close to and who
initially supported the BEST project.
A few amateur skeptics have raised legitimate (if minor) issues
which have appeared in the peer-reviewed literature and then been
included in the scientific process. And many others of course have
been legitimately confused by a confusing public debate, with the
resulting
impact on 'belief' in climate science.
Muller describes himself as "sceptical at the level that every
scientist tries to be sceptical" and also says:
"Many scientists signed petitions
supporting 'climate science' without ever looking at the legitimate
issues raised by the sceptics. I feel that if you sign a petition
and put your credentials after your name, then you should have
examined the issues with your scientific expertise first, and not
just joined a bandwagon of other scientists."
It is this kind of comment - with the inherent implication that
the BEST project team are the first to look objectively at the data
- which has
somewhat irritated climate scientists who have been working in
the area for years.
Muller still isn't convinced that the Intergovernmental Panel on
Climate Change (IPCC) is right about the degree of human influence
on global warming. He says:
"I have not done a scientific study, but
my own impression - based on reading the literature - is that some
of the warming we have seen is caused by humans. To my mind, you
can't rule out half of the warming being caused by humans, but I
think to conclude that most of it is - as the Intergovernmental
Panel on Climate Change says - could be an overestimate. This is my
personal impression; the other members of the team might feel
differently."
In this view Muller is at odds with the weight of scientific
evidence.
Carbon dioxide which comes from burning fossil fuels has a
distinct
manmade signal (explained further
here) - and the proportion of carbon dioxide in the atmosphere
that has this "human fingerprint" is rising. Skeptics frequently
cite
solar activity or other natural climate variation to explain
the warming trend. All of these natural elements have been
thoroughly investigated by climate scientists, and have been
ruled out as the dominant cause of warming.
These fundamental principals, added to the fact that there are
no plausible competing theories to explain the observed warming
trend, have convinced
97% of active climate scientists that humans are a significant
contributing factor to global warming.
Muller also explains the slight discrepancy between the
temperature records of from NASA and Hadley Centre data:
"We've already received feedback from
NASA, and we've resolved the difference with them. It turns out
that they had included some stations over water that we omitted;
when they omit them too the difference vanishes. The disagreement
with Hadley is of statistical interest only, because we have such
small error uncertainties. The Hadley Centre temperature change is
an outlier. It is smaller by a couple of tenths of a degree."
Overall, however, the interview is probably more interesting for
what it says about Muller than what it says about climate
science.