The Attribution Trap

Climate policy has been hamstrung for many years by the notion that the influence of greenhouse gas emissions on society (and the environment) through climate change can be precisely assessed, and that such attribution can be used to guide the policy response.  But what happens when the policy community asks the impossible from the science community?  Bad policy and bad science can result.

The importance of attribution is implicit in the definition of "climate change" used by the Climate Convention, which refers only to those changes resulting from anthropogenic changes in the chemistry of the atmosphere. Under this definition the Climate Convention seeks to create a demarcation of dangerous interference, which is usually defined as the "2 degree" target or a 450 ppm concentration level.  The presence of such a threshold in policy language thus encourages efforts to attribute various societal impacts of climate to human-caused climate change.  Without such attribution, who can say what dangerous effects are caused by greenhouse gas emissions?  But what does it say about the policy framework if issues of attribution are not so clear cut?

It is easy to make statements about attribution for generic, hypothetical events far in the future.  But it becomes far more difficult in the present when actual events with real impacts are actually taking place.  Here the attribution trap is even more obviously pathological.

Consider this discussion from the New Scientist (emphasis added):

[NCAR's Kevin] Trenberth agrees. "It comes to the question: given that there is a global warming component to an event, is there any way in which you can sue somebody for it? Who do you sue?" He points out, though, that it will always be difficult to rule out natural variation in climate. "It's going to be messy."

It already is. In 2005, victims of hurricane Katrina filed a lawsuit against a group of oil companies, claiming that they had created the environmental conditions in the Gulf of Mexico that strengthened Katrina. The case was dismissed in 2007, after it was ruled that the victims had no standing to sue because the harm could not be traced to individual defendants. That decision was reversed in 2009. But in June this year the US Court of Appeals for the Fifth Circuit again dismissed the case, this time because it did not have enough judges to form a quorum. In the process, the judges that were present ruled once more that the plaintiffs had no standing to sue.

There is another reason for finding out how much climate change is to blame for various events. "Hundreds of billions of dollars are potentially available [in a UN fund] to help developing countries adapt to climate change," says [Oxford' Myles] Allen. Who gets what share of the funds depends on being able to say which regions have suffered most as a result of climate change. For now, at least, that remains an open question.

Read that last paragraph again.  The ability of developing countries to access UN funds for adaptation depends upon their ability to attribute specific events to human-caused climate change from greenhouse gas emissions.  Because such attribution is not possible, this makes the entire policy basis of the fund flawed.  Just imagine the absurd notion of well-meaning UN officials coming to Africa explaining that they have the resources to help, say, malaria victims who have the disease as a result of human-caused climate change, but not any of the other victims of the disease.

Adaptation is not just a response to the marginal impacts of human-caused climate change, but rather to complex situations of vulnerability with inter-related and often inseparable social and climatic factors.  Improving the adaptive capacity of communities -- whether they be New Orleans or New Caledonia -- makes sense irrespective of the fraction of imapcts that can or cannot be attributed to human caused climate change.

Ultimately, the attribution trap makes adaptation a victim of the pathological politics of mitigation, where the policy framework encourages, even necessitates, claims with certainty of negative impacts due to greenhouse gas emissions.  Can climate policy be designed to succeed even if such attribution is either highly uncertain or even unknowable?  I think it can, but such an approach diverges a great deal from the course that we've been on.

For Further Reading

Pielke, Jr., R. A. 2004. What is climate change?. Issues in Science and Technology 20 (4) 31-34.

Pielke, Jr., R. A. 2005. Misdefining ‘‘climate change’’: consequences for science and action. Environmental Science & Policy 8 (6) 548-561.

See also Chapter 6 in The Climate Fix.