RCP8.5 tracks cumulative CO2 emissions

Climate simulation-based scenarios are routinely used to charac-terize a range of plausible climate futures. Despite some recent prog-ress on bending the emissions curve, RCP8.5, the most aggressive scenario in assumed fossil fuel use for global climate models, will continue to serve as a useful tool for quantifying physical climate risk, especially over near-to midterm policy-relevant time horizons. Not only are the emissions consistent with RCP8.5 in close agreement with historical total cumulative CO2 emissions (within 1%), but RCP8.5 is also the best match out to midcentury under current and stated pol-icies with still highly plausible levels of CO2 emissions in 2100.