View: "The IPCC says extreme climate scenarios are no longer plausible, by retiring the RCP8.5 scenario"
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This is simply incorrect, and a fundamental misunderstanding of the nature and purpose of the IPCC’s Representative Concentration Pathways (RCPs).
RCP8.5 was the highest greenhouse gas emission pathway of four hypothetical scenarios used to explore climate risks and test impact models resulting from different levels of greenhouse gas emissions. The RCP8.5 scenario has largely been superseded because the exceptionally high coal use it assumed no longer reflects a plausible future emissions pathway.
Whilst it is good news that the world has moved away from the most extreme emissions trajectories, the remaining IPCC RCPs still project around 2.5-3°C of warming this century, resulting in severe threats to civilisation including food shortages, health system breakdown and collapse of global ecosystems and economies.
More on this from Carbon Brief here
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The IPCC developed four Representative Concentration Pathways (RCPs) in the early 2010s, ranging from a high-end emissions scenario (RCP8.5) to the lowest emissions scenario (RCP2.6). The RCPs were designed to help scientists understand the consequences of different levels of greenhouse gas emissions, and provide benchmarks against which different climate policies could be assessed.
