I don't know about other scientists, but I've been thinking twice before hitting 'send' on my emails lately. The last thing I want is to nucleate "MagnetGate". Since it's been out of the public press for awhile, I'll remind you that 'ClimateGate' started when an unknown person (or persons) hacked into an e-mail server at the University of East Anglia. E-mails were posted on the web and climate 'skeptics' (more on that later) have highlighted passages they claim a) suggest scientists have manipulated data to show false evidence for human-made climate change and b) engaged in a conspiracy to prevent scientists with opposing opinions from being heard.
Let's start with the common ground: With the exception of the far fringes on the climate-change bell curve, everyone pretty much agrees that carbon dioxide (CO2) levels have been rising since the dawn of the Industrial Age, and that the rate of increase has become greater in the last 50 years. Greenhouse gases - like CO2 - provide a blanket for the Earth that holds in warmth. As the amount of greenhouse gases increase, the average temperature increases. The primary point of disagreement is whether the changes are 'anthropogenic' (human-caused). The proponents of anthropogenic climate change advocate that changing our behavior will allow us to bring the rising temperatures back down to a 'normal' range. Opponents claim that the fluctuations in temperature are within the normal range of climate variations and taking expensive measures to decrease greenhouse gas emissions is unnecessary and diverts that funding from other problems. With the exception of the extremes ("everyone become vegans and live in log cabins in Montana without electricity" and "Global warming is the biggest hoax ever") are a spectrum of opinions voiced by reputable scientists, as pointed out by Stephen K. Ritter in the cover story of this C&EN, a publication of the American Chemical Society. C&EN alone makes the dues for being an ACS member worthwhile.
Take the hockey stick plot (reproduced below) that shows temperature as a function of time. In particular, the y-axis shows the difference between the average temperature of the northern hemisphere and the time-averaged temperature between 1961 and 1990 (in degrees C) and the horizontal axis shows time in years. Y-axis values below zero mean that the average temperature was colder than the time-averaged temperature and data above zero mean that the temp was warmer than the selected temperature.
There are four different colors on the plot. The blue data use temperatures that have been inferred from tree rings, corals, ice cores and written records. Thermometer readings are in red. The black bumpy line is the average temperature for the northern hemisphere for that year. The gray lines are the error bars. Error bars denote how precisely (or with how much confidence) we know the temperature. In the early years, this plot tells us that we know the temperature to within a little better than half a degree either way.
I still haven't finished the literature about how we know the mean global temperature back in 1000 to within a degree when the thermometer hadn't even been invented. Galileo invented a water thermometer (which had some inherent measurement accuracy issues) in the 1590s. Fahrenheit invented the mercury thermometer in 1714. I'm guessing that's why the size of the error bars suddenly goes down around 1600.
But even with the best instrumentation, you have to worry about how and where measurements were made and how reproducible the measurements are. Cities are urban heat islands, meaning that the temperature within a city can be 1-5 degrees Fahrenheit different than that of a nearby rural area. If you put a thermometer too close to a building, it can measure reflected heat from buildings. You'll get a different measurement if you measure on asphalt or concrete because black surfaces absorb more heat than light surfaces.
Ritter's C&EN article mentions that Anthony Watts (who writes the 'Watts Up With That blog) checked 1070 of the 1220 stations in the U.S. Historical Climate Network, which is a subset of the 9000 weather stations throughout the US that are used to establish the mean US temperature. He claims that 91% of the stations fail the National Weather Service's requirements for placing outdoor thermometry.
Ritter does an outstanding job in his article of presenting the data and discussing the points on which different scientists disagree -- which was what I planned to do in this blog.
Luckily for me, he beat me to it, allowing me to comment on a couple of "things that make you go 'hmmm?" at the American Geophysical Union meeting.
First, be careful what you wish for. When Al Gore embraced climate change, I wondered what's not to like: more attention, more funding and a platform to communicate with the public. Talk to a few people on the frontlines of this issue to see how lucky they feel.
James Hansen, who heads the NASA Goddard Institute for Space Studies recounts going to Houston to give a talk just a few days after the hacked emails. A group of bloggers started the rumor that (since he wasn't implicated in the emails), he obviously had hacked the emails, removed his name and leaked the remaining material to discredit his competitors. His hosts felt they needed to provide him with a police escort. There were even calls for capital punishment for Hansen. OK, so maybe climate scientists aren't so lucky after all.
Hansen recounts in a recently published essay that ClimateGate-type situations have happened before. He cites some previous cases in which honest errors in data analysis (or provision) were used for sensational headlines that implied that the government or individual scientists had purposely misled people.
Some of the most talked of the Climategate emails is correspondence between Phil Jones, director of the Climate Research Unit at UEA and Michael Mann of Penn State. For example, the following from Jones:
"I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith's to hide the decline."
The anti-anthropogenic climate people claim this is evidence that scientists are manipulating the data. Mann says that the 'trick' was replacing proxy temperatures inferred from tree rings with actual air temperatures for dates after 1960. The more accurate temperatures he substituted change the trends in the data. 'Trick' doesn't denote sneaky or underhanded: It means a clever way of making something soluble. The technique of substitution of variables in calculus was introduced as a trick.
After a bit of reluctance, Jones is releasing data so that others can re-check how his group manipulated it and verify that their conclusions are still valid. As with Hansen's cases, questions were raised, and the science has to be re-visited. This is how science is supposed to work: Scientists debate the issue in the open, peer-reviewed literature and a consensus view emerges.
Questioning the reproducibility or validity of results in not at all uncommon in science. I think what troubles people more are the emails in which it appears that Jones is out to prevent competitors from publishing in the peer-reviewed literature, getting some 'activist journals' excluded from being considered part of the peer-reviewed literature, or preventing some existing peer-reviewed literature from getting into the next IPCC (International Panel on Climate Change) study. My initial response to this was "OK, so people are surprised that scientists are people? We have feelings, we have jealousies, and we sometimes behave in ways that won't win us the 'Dr. Congeniality' prize." But attending the AGU meeting gave me a new perspective. As Ritter writes in his C&EN article (with the bolding mine):
"Skeptics counter that the "climategate" emails prove IPCC and leading climate scientists have evolved from being brokers of scientific information on climate science to being gatekeepers of information, preventing some valid but contradictory data from coming to light."
I am certainly don't know enough about the intricacies of climate data to say whether this is what is happening here, but it again wouldn't be the first time. Newton is famous for his rivalries with, well, just about everyone, usually over claiming credit for coming up with ideas. This included Hooke, and Leibniz. Edison did some pretty rotten things to his competitors, including Tesla. More recently, Gallo and Montagne quarreled over who had first discovered the AIDS virus, which included charges that Gallo had stolen the virus from Montagne's lab. (Congressional and NIH inquiries cleared Gallo of these charges.) There are many stories -- anecdotal and well-documented of scientists conspiring to prevent rivals from publishing first (or at all), of scientists stealing ideas from proposals they have reviewed, and a growing list of retracted papers with either outright fraud or sloppy work.
What constitutes gatekeeping data (selectively keeping or discarding data, and not sharing key data sets with others so that they cannot try to reproduce your results) is difficult question. If you've painstakingly gathered data, why should you have to turn over your work so that other people can data mine it and beat you to results? On the other hand, science is founded upon the concept that scientific results are valid because other people can perform the same experiments and come to the same conclusions. The scientific method relies on replication and debate, and it is difficult to have that debate if the original data are not accessible.
I went to a series of climate change-related talks at the AGU meeting to see what "the community" thought. I could divide people into roughly two groups: The first group are in-the-trenches scientists giving talks about very specific problems within their subfields of climate research. Their results were presented very objectively, they pointed out uncertainties in their conclusions and showed evidence to counter questions raised by the audience. The second group of speakers had a agenda that was more advocacy than science.
As a graduate student at an Association of Women in Science leadership conference, I remember clearly being irritated by a speaker who assumed that, because we were women in science, we were all liberal Democrats and antagonistic to the then-Republican-dominated administration. The 'All intelligent people find this obvious' attitude bugs me because it is so antithetical to what science is all about: evidence and open debate. I was, at the time, a card-carrying Democrat wholly antagonistic to the administration, but I'm also a scientist. My view then and now is: Show me the evidence and let me make up my own mind. Don't tell me what to think.
I went to a town hall at AGU entitled "Talking Climate". A town hall is not a scientific research session per se, but more informal. The blurb for the town hall was:
The public has significant gaps in its understanding of climate change. Naturally, scientists are best equipped to fill these gaps. However, many scientists are unaware or untrained in how to best convey their ample knowledge to non scientists. Because they're already experts in their field, they can make inaccurate assumptions about other people's understanding of weather, climate, and human-caused warming. Our goal is to cultivate an educated public that can make informed decisions. In this town hall meeting, communications professionals will provide the basics of delivering accurate yet easy-to-understand science to the public and the media.
I was hoping to get from the session (which was very respectably attended for 7:15 in the evening) some information that would help me address people who ask questions about the hockey stick plot. The web tells you that it's right and that it's wrong, and it is really hard to tell which of the sites I should believe.
The conveners were Kim Curtis, a former AP reporter and now with the communications firm resource|media, and science & technology writer/editor Susan Hassler. (I hope I have Susan's name right, as I couldn't find it in the program.) There was some valuable information from the session: For example, Hassler had a list of words scientists use differently from their conventional meaning. For example, 'aerosol' to most people conjures up a can of hairspray, not particles suspended in the air. Words like 'bias', 'error', 'exploit', 'scheme', 'proposal', and 'risk' have very specific meanings and when we use them in discussions with journalists or the public, we are asking for things to be taken out of context. They covered some important points about not assuming too much knowledge on the part of your audience, not using jargon, not allowing details to obscure the main point, and making numbers meaningful by comparing them to things people have direct experience with.
However, I started getting a little uncomfortable when Ms. Curtis compared a statement from an IPCC report
"most of the observed increase in global average temperature since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations"
with a quote from an NRC report.
"The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability. Human-induced warming and associated sea level rises are expected to continue through the 21st century... The IPCC's conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue."
Ms. Curtis criticized the NRC report for not making the point as clearly as the IPCC report. I understand that a communications company is paid to support a particular point of view; however, the NRC report was from 2001, while the IPCC report is from 2007. That statement was likely the strongest the panel felt comfortable making at that time. Having been on a NRC panel, I know there is a lot of wordsmithing done to ensure that the conclusions are defensible based on the evidence. Ms. Curtis also showed only a portion of the IPCC quote. The full quote is:
"Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations. It is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent (except Antarctica)."
You have to read carefully to figure out the difference between the two sentences. The second sentence addresses warming over each continent as opposed to over the globe as a whole. I was very disappointed that the session was really more on how to advocate without providing the evidence I as a scientist would need to feel comfortable talking about the issue. I read the IPCC executive summary myself to determine what I thought they were actually comfortable saying.
A later session was PA24A "Providing Climate Policy Makers with a Strong Scientific Base". Again, the 'intelligent people don't need to be convinced of...' attitude was pretty evident. What bothered me most was typified by a statement by Ann Staudt of the National Wildlife Federation in which she said that anyone who didn't believe in anthropogenic climate change wasn't really a scientist. Similar comments had been made in the town hall. Ritter points out in his C&EN article that some typify dissenters as 'climate-change antagonists', or 'deniers'. Have even scientists lost the idea that science should be the objective voice of reason?
There is an outstanding editorial in the LA Times by Daniel Sarewitz and Samuel Thernstrom, two scholars with very very divergent political bents, but some common conclusions. Scientists claim some type of ultimate authority by being above the fray and answering only to Nature (the entity, not the journal). Sarewitz and Thernstrom point out that it has never been the case that scientists are unbiased providers of the Truth, and that "Science, in other words, is replete with the same human failings that mark all other social activities." They conclude:
The real scandal illustrated by the e-mails is not that scientists tried to undermine peer review, fudge and conceal data, and torpedo competitors, but that scientists and advocates on both sides of the climate debate continue to claim political authority derived from a false ideal of pure science. This charade is a disservice to both science and democracy. To science, because the reality cannot live up to the myth; to democracy, because the difficult political choices created by the genuine but also uncertain threat of climate change are concealed by the scientific debate.
I entered science with the naive ideal of a field in which everyone was engaged in a search for Truth (the concept, not the elementary particle). The fact that there really isn't a 'pure science' because evidence early in my career when I found some graduate students had solutions manuals and others formed exclusive study groups. Then there's grant getting, tenure... I've fallen out of the ivory tower. It's not a secret in the scientific community we sometimes eat our own young, that people fall so much in love with their own theories that they become unable to even consider other points of view, or that some scientists forge data for publications and attention. But so far (mostly) the scientific method has worked. I will never win an argument to change the charge on the electron because everyone else can measure it and see that I'm wrong.
The problem is that the science of climate change is so complex and uncertain that -- if this is as imminent a danger as some project -- we don't have time to figure it out before we decide to do something. Perhaps ClimateGate is a good thing in the end because it shows the public that not all science is as certain as the measurement of the acceleration due to gravity they made in high school. Perhaps scientists, like medical doctors taking money from the pharma companies or journalists writing about people they know personally, should be required to disclose their sympathies.
I'll start. I agree with AGU's position statement on climate change. I believe in anthropogenic climate change, but I think there is a lot of uncertainty about how bad it could be. Recognizing the inherent uncertainties in a fluctuating, aperiodic, non-linear system, and the fact that there may be some significant questions about some of data and its interpretation, it still seems to me that if we don't act now and the worst case is right, we may not have another chance. It's almost Pascal's wager. You might as well believe in climate change because if we are in a natural cycle and the temperatures come back down, we're out money. If it's not a natural cycle and we do nothing, we're pretty much screwed.
That's a practical and decidedly unscientific opinion. But perhaps there is still some white shining though the soot on the ivory tower. Even though, science may not be 'pure' as Sarewitz and Thernstrom put it, that doesn't mean we shouldn't strive for it to be so.