Whenever you read a media story about how we’re heading toward catastrophe if we continue operating “business as usual” — i.e., if we don’t slash carbon emissions — the reports are almost always referring to a model simulation using RCP8.5.
And you can bet that nowhere in the story will they explain that RCP8.5 is an implausible worst-case scenario that was never meant to represent a likely base case outcome, or that scientists have begun castigating its usage as a prediction of a doomed business-as-usual future.
The term RCP8.5 refers to a greenhouse gas emissions scenario often used by scientists for climate model projections. You might never have heard of RCP8.5 but you have definitely heard of forecasts based on it.
Listening to the politicians who make the strongest pleas for radical climate action, it is clear that their fears for the future are driven by RCP8.5 scenarios, yet it is also clear that they have no idea what it is or what is wrong with it.
RCP stands for “Representative Concentration Pathways,” or projections of how much carbon dioxide (CO2) will accumulate in the atmosphere due to fossil fuel use over the coming century.
For the rest of this article: https://business.financialpost.com/opinion/ross-mckitrick-the-flaw-in-relying-on-a-worst-case-scenario-climate-model