by Roger Pielke, October 7, 2019 in Forbes

Underlying discussion and debate of climate policies are computer models that bring together idealized representations of policies, economics and climate to estimate the impacts of future climate change and the benefits of mitigation. Such models, typically called integrated assessment models, are incredibly technical and complex. At the same time, they are also simplistic toys. Here I argue that while these models are valuable for exploring concepts and ideas, they have come to serve as a huge distraction when it comes to the development of actual policies that have a chance to accelerate rates of decarbonization in the real world.

Before proceeding, it is important to note that climate change poses real risks to our collective future, and aggressive mitigation and adaptation policies make good sense. However, the pace of progress, particularly on mitigation, has been frustratingly slow.

One way that integrated assessment models warp our discussion of climate policies is through the pervasive use of what are called “baseline scenarios.” These scenarios seek to represent where the world may be headed into the future in the absence of climate policies. Here is how the Intergovernmental Panel on Climate Change (IPCC) defines such scenarios, and their role in evaluating futures with climate policy (called “mitigation scenarios”):

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Methodological debates are of course common in policy research. But in no area of policy that I have encountered over the past 30 years as a policy researcher have I come across a subject matter both as important as climate change and completely captured by one school of thought.

Scenario planning has an important role to play in the tool box of policy analysts. However, in the case of climate change, scenarios generated by integrated assessment models have overwhelmingly become the main tool of analysis in climate policy, to the exclusion of other valuable approaches. The result of this methodological myopia is that much of our collective intellectual attention has been spent on trying to figure out how to address climate change in models, and not in the real world.