Fifth national climate assessment emphasizes mitigation

The latest National Climate Assessment highlights historic emissions reductions and outlines new guidance for achieving a net-zero emissions pathway.

The National Oceanic and Atmospheric Administration recently announced that 2023 is on track to be the hottest year in its recorded history. Furthermore, all 10 of the hottest years on record have occurred since 2010, according to data from the Global Climate Change program at the NASA. Informed by accumulating evidence, climate scientists and other experts have been sounding the alarm about the dangers of pollution and humanity’s role in exacerbating climate change as early as 1965.

Oil refinery with business analytics overlaid.
Image: iStock/RonFullHD

As part of a response to these warnings, in 1990 Congress passed the Global Change Research Act, which requires the U.S. Global Change Research Program (USGCRP) to deliver periodic reports to Congress and the President on the current status of climate science, the extent of climate impacts, and trends in global change.

In November, the USGCRP released its fifth national climate assessment. The report’s mitigation chapter spells out those steps to reduce emissions, including summarizing progress to date and identifying “pathways to drastically cut emissions in ways that improve human health, protect jobs, save resources, and redress historical inequities.” The report includes key contributions by co-author Sanya Carley, now the faculty co-director of the Kleinman Center for Energy Policy and the Presidential Distinguished Professor of Energy Policy and City Planning at Penn—the mitigation chapter authors combined their expertise in earth science, economics, and climate modeling to outline options for greater emissions mitigation.

As part of the chapter, the authors also invite industry contributors to propose usable net-zero emissions pathway models, which will be added to an open database of decarbonization scenarios.

The chapter offers five key messages that, taken together, could help the U.S. meet its international climate commitments and support efforts to reduce global emissions. First, the chapter concludes that successful mitigation requires reaching net-zero emissions. The authors note that net GHG emissions would need to decline at a rate that is more than six times faster than the current rate in order to meet current national climate targets and international temperature goals.

This story is by Cece Coffey. Read more at the Kleinman Center for Energy Policy.