Monday, December 23, 2019

In 2020 Climate Science Needs To Hit The Reset Button, Part One

Roger Pielke
 
In a remarkable essay last week titled, “We’re Getting a Clearer Picture of the Climate Future — and It’s Not as Bad as It Once Looked,” David Wallace-Wells of New York Magazine wrote, “the climate news might be better than you thought. It’s certainly better than I’ve thought.” The essay was remarkable because Wells, a self-described “alarmist,” is also the author of The Uninhabitable Earth, which describes an apocalyptic vision of the future, dominated by “elements of climate chaos.”
According to Wallace-Wells, his new-found optimism was the result of learning that much discussion of climate change is based on extreme but implausible scenarios of the future where the world burns massive amounts of coal. The implausibility of such scenarios is underscored by more recent assessments of global energy system trajectories of the International Energy Agency and United Nations, which suggest that carbon dioxide emissions from the burning of fossil fuels will be relatively flat over the next several decades, even before aggressive climate policies are implemented.
Scenarios of the future have long sat at the center of discussions of climate science, impacts and adaptation and mitigation policies. Scenario planning has a long history and can be traced to the RAND Corporation during World War 2 and, later (ironically enough) Shell, a fossil fuel company. Scenarios are not intended to be forecasts of the future, but rather to serve as an alternative to forecasting. Scenarios provide a description of possible futures contingent upon various factors, only some of which might be under the control of decision makers. 
The climate community got off track by forgetting the distinction between using scenarios as an exploratory tool for developing and evaluating policy options, and using scenarios as forecasts of where the world is headed. The scenario (or more precisely, the set of scenarios) that the climate community settled on as a baseline future for projecting future climate impacts and evaluating policy options biases how we think about climate impacts and policy responses. The point is not that climate analysts should have chosen a more realistic future as a baseline expectation, but rather, they should never have chosen a particular subset of futures for such a baseline.

 

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