The United Nations’ Intergovernmental Panel on Climate Change threw out one of its most extreme emissions scenarios last week, a major development in climate science that will likely echo across markets, federal and state government policy, and education.
What is RCP 8.5?
RCP 8.5 is the stuff of climate apocalypse nightmares. RCP stands for Representative Concentration Pathway, a future climate scenario Earth could face by the end of the century if no policies were adopted to address climate change.‘Concentration’ refers to greenhouse gas concentrations in Earth’s atmosphere, and the 8.5 refers to the amount of additional heat those gases would trap by 2100.
RCP 8.5 became the highest-emission climate scenario widely used in both academic research and media coverage over the past decade. But last week, the panel determined that RCP 8.5 described a future that subsequent data has shown to be too implausible to remain a useful benchmark for climate projections.
Why is the panel’s decision-making headlined?
The panel’s decision was significant because of how influential RCP 8.5 has been, not only within the field of climate science, but within academia, the media, business and government. It became foundational in climate science education, shaped outward-facing climate communication and was sometimes utilized in localized climate-impact modeling.
It influenced corporate climate-risk assessments used by insurance companies, banks and investment firms to evaluate long-term property and infrastructure risks, which can affect insurance costs and investment decisions. It also informed some taxpayer-funded climate planning and policy analysis at the federal level.
Reactions to the IPCC’s decision are varied
Some scientists and policy analysts have welcomed the change and said RCP 8.5 was obviously an unreliable benchmark since its inception.
