Matthew Nisbet is associate professor of communication at Northeastern University and a Committee for Skeptical Inquiry scientific consultant. From 1997 to 1999, he was public relations director for CSI.
Late last year at the United Nations climate change summit in Paris, world leaders reached a historic accord committing their countries to lowering greenhouse gas emissions over the next two decades and beyond.
The combined commitments by countries fall short of what many scientists say is needed to avoid the worst impacts of climate change, but the Paris accord marks an essential first step. World leaders pledged to revisit their commitments every five years with the goal of ratcheting up efforts to rapidly reduce emissions.