SOURCE: Woods Hole Research Center

DATE: August 3, 2020

SNIP: The RCP 8.5 CO2 emissions pathway, long considered a “worst case scenario” by the international science community, is the most appropriate for conducting assessments of climate change impacts by 2050, according to a new article published today in the Proceedings of the National Academy of Sciences. The work was authored by Woods Hole Research Center (WHRC) Risk Program Director Dr. Christopher Schwalm, Dr. Spencer Glendon, a Senior Fellow at WHRC and founder of Probable Futures, and by WHRC President Dr. Philip Duffy. Long dismissed as alarmist or misleading, the paper argues that is actually the closest approximation of both historical emissions and anticipated outcomes of current global climate policies, tracking within 1% of actual emissions.

“Not only are the emissions consistent with RCP 8.5 in close agreement with historical total cumulative CO2 emissions (within 1%), but RCP8.5 is also the best match out to mid-century under current and stated policies with still highly plausible levels of CO2 emissions in 2100,” the authors wrote.

The article also notes that RCP 8.5 would not be significantly impacted by the COVID-19 pandemic, adding that “we note that the usefulness of RCP 8.5 is not changed due to the ongoing COVID-19 pandemic. Assuming pandemic restrictions remain in place until the end of 2020 would entail a reduction in emissions of -4.7 Gt CO2. This represents less than 1% of total cumulative CO2 emissions since 2005 for all RCPs and observations.”

“Given the agreement of 2005-2020 historical and RCP8.5 total CO2 emissions and the congruence between current policies and RCP8.5 emission levels to mid-century, RCP8.5 has continued utility, both as an instrument to explore mean outcomes as well as risk,” they concluded. “Indeed, if RCP8.5 did not exist, we’d have to create it.”