“E-mail furor doesn’t alter evidence for climate change”
I cannot condone some things that colleagues of mine wrote or requested in the e-mails recently stolen from a climate research unit at a British university. But the messages do not undermine the scientific case that human-caused climate change is real.
After their widely criticized lapse in judgment in publishing an op-ed on climate science (!) by Sarah Palin (see “Washington Post goes tabloid, publishes second falsehood-filled op-ed by Palin in five months“), the Post has now published two pieces by actual scientists in response. The first, published online, was by Alan Leshner, CEO of the American Association for the Advancement of Science and executive publisher of the journal Science (see “Don’t let the climate doubters fool you“).
And now, finally, they have published a piece in their print edition, by climatologist Michael Mann — of the much attacked and much vindicated hockey stick graph (see (see NAS Report and RealClimate.org).
Mann is a genuine climate scientist, Palin, not so much. Sadly, seeing climate change up close provided the ex-Governor no more insight into anthropogenic global warming than seeing Russia from her home state provided her insight into U.S. foreign policy. And that was one of the many points Mann made about man-made global warming [sorry, couldn't resist that one].
Since Palin’s piece was very widely read, I’m going to repost the rest of Mann’s in its entirety:
The hacked e-mails have been mined for words and phrases that can be distorted to misrepresent what the scientists were discussing. In a Dec. 9 op-ed, former Alaska governor Sarah Palin argued that “The e-mails reveal that leading climate ‘experts’ . . . manipulated data to ‘hide the decline’ in global temperatures.” Yet the e-mail she cites was written in 1999, just after the warmest year ever recorded (1998) to that date. It could not possibly have referred to the claim that global temperatures have declined over this decade — a claim that is false (the current decade, as has been recently reported, will go down as the warmest on record).
In one case, professor Phil Jones of the University of East Anglia refers to a “trick” regarding temperature data that he attributes to an article that co-authors and I published in the journal Nature in 1998. We showed one up-to-date temperature data set from thermometer measurements along with a longer data set, based on calculations from natural “proxy” records such as ice cores, corals and tree rings, that ended in 1980. The “trick” (by which scientists generally mean a clever solution, i.e., a “trick of the trade”) was that the longer-term record could be viewed in the context of recent temperature measurements.
There was nothing secret about this. Both temperature curves were clearly labeled in our Nature article, and anyone could download the data we plotted. The National Academy of Sciences reviewed this work in 2006 in a study reported by this newspaper ["Past Few Decades Warmest on Record, Study Confirms," news story, June 23, 2006]. Members of the peer-review panel said that they “saw nothing that spoke . . . of any manipulation” and that the study was “an honest attempt to construct a data analysis procedure.”
In the same e-mail, Jones uses the phrase “hide the decline” in reference to work by tree-ring expert Keith Briffa. Because tree-ring information has been found to correlate well with temperature readings, it is used to plot temperatures going back hundreds of years or more. Briffa described a phenomenon in which the density of wood exhibits an enigmatic decline in response to temperature after about 1960. This decline was the focus of Briffa’s original article, and Briffa was clear that these data should not be used to represent temperatures after 1960. By saying “hide the decline,” Jones meant that a diagram he was producing was not to show those data during the unreliable post-1960 period.
The conspiracy theories about the e-mails are fueled in part by their criticisms of the quality of two papers regarding global warming and a suggestion that at least one of the papers be kept out of an Intergovernmental Panel on Climate Change report. As Nature noted in a recent editorial, neither the e-mail writers nor the IPCC suppressed any findings. Both papers were included in the IPCC’s report. Some statements in the stolen e-mails reflect poor judgment — for example, a colleague referring to deleting e-mails that might be subject to a Freedom of Information Act request — but there is no evidence that this happened.
Palin wrote that Alaska’s climate is changing but referred to “thawing permafrost and retreating sea ice” as “natural, cyclical environmental trends.” In fact, such changes are among the effects scientists predicted would occur as greenhouse gas levels increase. Scientific evidence for the reality of human-caused climate change includes independently replicated data documenting the extent of warming; unprecedented melting of glaciers; rises in global sea levels; increasingly widespread continental drought; and models that predict all of these things but only when human impacts are included. Those same models project far more profound and potentially damaging impacts of climate change if we do not take action to stabilize greenhouse gas levels.
The scientific consensus regarding human-caused climate change is based on decades of work by thousands of scientists around the world. The National Academy of Sciences has concluded that the scientific case is clear. As world leaders work in Copenhagen to try to combat this problem, some critics are seeking to cloud the debate and confuse the public.
- Exclusive audio of press call today with Michael Mann, Gavin Schmidt, and Michael Oppenheimer on “Climate Science: Setting the Record Straight”
- Must read AP analysis of stolen emails: An “exhaustive review” shows “the exchanges don’t undercut the vast body of evidence showing the world is warming because of man-made greenhouse gas emissions.”
- Nature editorial: “Nothing in the e-mails undermines the scientific case that global warming is real “” or that human activities are almost certainly the cause.”
- 1700 UK scientists come forward to reaffirm climate science
- The American Association for the Advancement of Science reaffirms “The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society.”
- American Meteorological Society reaffirms “that the atmosphere, ocean, and land surface are warming; that humans have significantly contributed to this change; and that further climate change will continue to have important impacts on human societies”¦.”
- Statement on stolen emails by IPCC Working Group I on basic climate science
- Debunking Misinformation About Stolen Climate Emails