Last weekend was a good one for climate-change deniers. A hacker stole and released scores of documents, including personal e-mail exchanges, from a server at Britain's Climate Research Unit at the University of East Anglia, a premier climate-change research center. "This is not a smoking gun; this is a mushroom cloud," proclaimed one skeptic.
Not quite. Assuming the documents are genuine — the authenticity of all has not been confirmed — critics are taking them out of context and misinterpreting at least one controversial e-mail exchange. None of it seriously undercuts the scientific consensus on climate change. But a few of the documents are damaging for other reasons.
According to one of the stolen e-mails, CRU director Phil Jones wrote that he would keep papers questioning the connection between warming and human activity out of the authoritative Intergovernmental Panel on Climate Change report "even if we have to redefine what the peer-review literature is!" In another, Jones and Pennsylvania State University's Michael E. Mann write of organizing a boycott of an academic journal until it fires a "troublesome editor." Other e-mails speak of withholding data from climate-change skeptics. Many — including us — find global warming deniers' claims irresponsible and their heated criticism of climate scientists unconvincing. But the point of peer review is to let ideas stand or fail on their own, in public.
Whatever else comes out about the stolen documents, they have become examples of how not to react to climate-change deniers. You need not dig very far into the stolen documents to discover why climate researchers shouldn't overstate an already strong case. One discusses how scientists can't account for a recent, measured lack of warming — a fact that climate-change deniers use to ignore the massive body of evidence that global warming could be a dire threat. Really, it demonstrates that Earth's systems are extremely difficult to predict in detail.
By our reckoning — and that of most scientists, policymakers and almost every government in the world — the probability that the planet will warm in the long term because of human activity is extremely high, and the probability that allowing it to do so unabated will have disastrous effects is unacceptably large. The case that governments should hedge against that outcome is formidable enough. Climate scientists should not let themselves be goaded by the irresponsibility of the deniers into overstating the certainties of complex science or, worse, censoring discussion of them.