Instead of fighting carbon emissions that threaten to undermine our economy, a group of scientists have looked at the benefits of curbing ozone precursors and black carbon.
National benefits of the CH4 plus BC measures versus the reference scenario. Circle areas are proportional to values for (A and B) climate change, (C and D) human health (values for population over age 30), and (E and F) agriculture. Surface temperature changes are from the GISS-E2-S simulation. Health, agriculture, and atmospheric forcing impacts are based on the average of GISS and ECHAM concentration changes and are for 2030 and beyond. Uncertainties are ~60% for global mean temperatures, with national scale uncertainties likely greater, ~60% for atmospheric forcing, ~70% for health, and roughly –70%/+100% for crops [see (7) for factors included in uncertainties, most of which are systematic for atmospheric forcing, health, and agriculture so that much smaller differences between regions are still significant]. Interactive versions providing values for each country are at www.giss.nasa.gov/staff/dshindell/Sci2012, whereas alternate presentations of these data are in fig. S5 and table S5.
The benefits of controlling methane and soot emissions turned out to be considerable. Largely thanks to reduced methane emissions, global warming by 2050 would be reduced by about half a degree; global warming so far has amounted to about 0.8°C. The additional controls also ensure that the low-carbon scenario holds warming below the danger level of 2°C of warming, at least for the next 60 years. Methane controls would also keep ozone low enough to avoid annual crop losses of 30 million to 135 million metric tons in 2030
The drop in outdoor air pollution, due largely to soot emission reductions, would avoid 700,000 to 4.7 million premature deaths each year. Indoors, more than one-third of a million lives would be saved annually in India and China alone. A total of at least a million lives saved a year compares with the 600,000 premature deaths from tuberculosis expected in 2030 or the 2.1 million deaths due to traffic accidents. – from Richard A. Kerr discussing Shindell et al…
Shindell, Drew, et al.2012. Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security, Science January 2012: Vol. 335 no. 6065 pp. 183-189 DOI: 10.1126/science.1210026 www.sciencemag.org/content/335/6065/183.full
Via the NYtimes, see also http://www.sciencemag.org/content/335/6065/156.full for the editorial analysis.