Poster's note : in my view there is a credible case for early geoengineering to deal with the warming consequences of this reduced sulfur load
http://earthzine.org/2016/05/20/could-cuts-in-sulfur-from-coal-and-ships-help-explain-the-2015-spurt-in-northern-hemisphere-temperatures/ Could cuts in sulfur from coal and ships help explain the 2015 spurt in Northern Hemisphere temperatures? Published on Friday, 20 May 2016 11:07 By Daniel S. Cohan, Associate Professor, Rice University Nir Y. Krakauer, Associate Professor, City College of New York James J. Corbett, Professor, University of Delaware Daran Rife, Global Head of Mesoscale Modeling, DNV GL – Renewables Advisory Rui Zhang, Postdoctoral Researcher, Rice University Anna Ruth Halberstadt, Graduate Student, Rice University Leah Y. Parks, Associate Editor, Electricity Policy Reductions in cooling sulfate aerosols may have contributed to recent warmth. The year 2015 was the warmest in recorded history, and featured an intense El Niño event in the second half of the year. Since global temperatures have been increasing alongside greenhouse gas (GHG) concentrations and also correlate with the El Niño Southern Oscillation (ENSO), both the U.S. National Centers for Environmental Information and the Australian Bureau of Meteorology indicate that El Niño was a major contributor to the 2015 record warmth (NOAA 2016; BoM 2016). We offer a hypothesis for an additional contributor to the record global warmth in 2015: a reduction in sulfur emissions from the combustion of coal and of petroleum-derived ship fuel. Sulfur emissions have been cut in order to reduce the health impacts of the sulfur dioxide (SO2) pollutant and of the particulate matter (sulfate aerosols) that subsequently forms in the atmosphere. However, sulfate aerosols also provide a cooling veil by scattering sunlight, brightening clouds, and extending cloud size and lifetime (IPCC 2013). Reducing sulfate aerosols could curtail this atmospheric cooling effect (Fiore et al. 2015), and thus contribute to the observed record-breaking 2015 temperatures. This paper reviews the temperature anomalies of 2015, and presents evidence both consistent with and contradictory to a contributing role of sulfur cuts in recent warming. We suggest the hypothesis presented merits scientific attention in climate models and observations. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
