A 22-member strong team of scientists headed by Drew Shindell (NASA) has presented a new plan for global warming mitigation in the journal Science this week (DOI). This plan specifically aims to combine the benefits of global cooling with improved health and improved food security. It does so by targeting emissions of black carbon (cause: incomplete combustion of fossil fuels), methane (cause: rice paddy's, methane production losses, global warming effect 25 times that of carbon dioxide) and that of ozone (formed from ozone precursors methane, carbon monoxide and NOx in combination with solar radiation).
A total if 400 different measures for example promoting of brick kilns, promoting clean-burning stoves, reducing gas leaks in gas pipelines are proposed. Regions like Western Europe and Canada would be largely unaffected but regions like China (dirty coal mining, rice paddies) and the US (municipal waste) would be greatly affected.
Based on climate modelling, a reduction of global warming by 0.5 degrees in 2050 is possible with effects mostly around the poles. In terms of precipitation India will get a lot dryer, The Black Sea region a lot wetter. More importantly in terms of health effects a reduction of up to 4 million avoidable deaths per year globally is possible by 2030. Compare that to the 8 million deaths from tobacco use. Ozone negatively affects crop yields. A country like China may look forward to an increase in annual crop production of around 10,000 kiloton.
The combined monetary gains for methane abatement are estimated at 1100 dollars for every metric ton. Any measure costing less than this amount can be considered a sensible investment. This would involve 50 megaton per year of methane.
Have climate scientists discovered common sense? One of the central doctrines of the more moderate climate sceptics is that as long the Global Warming Controversy continues and as long as more and more governments are walking away from global warming measures, it makes more sense to focus on those measures that have other measurable benefits as well. Fighting air pollution and improving food security anyone can agree on.