Policies to curb short-lived climate pollutants could yield major health benefits

Controlling soot, methane, hydrofluorocarbons would yield immediate effects

May 3 2017 Duke University

Methane and black carbon — or soot — are the second and third most powerful climate-warming agents after carbon dioxide. They also contribute to air pollution that harms the health of billions of people worldwide and reduces agricultural yields.

“Unlike long-lived greenhouse gases such as carbon dioxide, SLCPs respond very quickly to mitigation. It’s highly likely that we could cut methane emissions by 25 percent and black carbon by 75 percent and eliminate high-warming hydrofluorocarbons altogether in the next 25 years using existing technologies, if we made a real commitment to doing this,” said Drew T. Shindell, professor of climate science at Duke University’s Nicholas School of the Environment.

Acting now to reduce these emissions would contribute to long-term goals set under the 2015 Paris Climate Agreement while concurrently offering governments substantial benefits in the short term for investing in sustainable development — a set of goals through 2030 that countries also agreed to in 2015….

..they point out that in addition to saving human lives and boosting global food security, curbing SLCPs will significantly slow the pace of climate change over the next 25 years. This could help reduce biodiversity losses and slow amplifying climate feedbacks such as snow-and-ice albedo that are highly sensitive to black carbon….

….Maintaining separate reporting methods for each pollutant would provide a clearer understanding of the benefits associated with SLCPs’ reduction.

Targeting immediate reductions in SLCP emissions is the most beneficial path we can take toward achieving the Paris Climate Agreement’s goal of reducing warming by 2C,” Shindell said…

D. Shindell, N. Borgford-Parnell, M. Brauer, A. Haines, J. C. I. Kuylenstierna, S. A. Leonard, V. Ramanathan, A. Ravishankara, M. Amann, L. Srivastava. A climate policy pathway for near- and long-term benefits. Science, 2017; 356 (6337): 493 DOI: 10.1126/science.aak9521