News Releases

The CECP Team presented our ongoing work at the annual MIT Energy Night, which was held Friday, October 16, 2015, at the MIT Museum. This public event showcases energy-related activities at MIT, including presentations from research laboratories, student groups, and early stage energy startups based on technologies developed at MIT. The CECP team interacted with a broad audience of scholars, policy makers, business professionals, and students interested in learning more about our ongoing work. For more information, please see http://mitenergynight.org/.

Photos from the event:

Mark Dwortzan | MIT Joint Program on the Science and Policy of Global Change

Climate CoLab, an MIT-based crowdsourcing platform to advance climate change solutions through the power of collective intelligence, has named Langley DeWitt, a research scientist with the Center for Global Change Science, as a Judges’ Choice winner in one of 15 contests for 2015. DeWitt, who is also chief scientist of the Rwanda Climate Observatory, was recognized in the Transportation contest for her proposal to set up an inexpensive air quality sensor network in Kigali, Rwanda as part of an effort to reduce vehicular emissions and improve air quality.

DeWitt and other contest winners will present their ideas at MIT's Solve and Crowds & Climate conferences, October 5 and 6 on the MIT campus, where the $10,000 Grand Prize will be awarded.

Read more about DeWitt's proposal here.

Mark Dwortzan
MIT Joint Program on the Science and Policy of Global Change

MIT researchers find unintended consequences
 
Like the leaves of New England maples, phytoplankton, the microalgae at the base of most oceanic food webs, photosynthesize when exposed to sunlight. In the process, they absorb carbon dioxide from the atmosphere, converting it to carbohydrates and oxygen. Many phytoplankton species also release dimethyl sulfide (DMS) into the atmosphere, where it forms sulfate aerosols, which can directly reflect sunlight or increase cloud cover and reflectivity, resulting in a cooling effect. The ability of phytoplankton to draw planet-warming CO2 from the atmosphere and produce aerosols that promote further cooling has made ocean fertilization—through massive dispersal of iron sulfite and other nutrients that stimulate phytoplankton growth—an attractive geoengineering method to reduce global warming.

But undesirable climate impacts could result from such a large-scale operation, which would significantly increase DMS emissions. The primary source of sulfate aerosol over much of the Earth’s surface, DMS plays a key role in the global climate system. In a study published in Nature’s Scientific Reports, MIT researchers found that enhanced DMS emissions, while offsetting greenhouse gas-induced warming across most of the world, would induce changes in rainfall patterns that could adversely impact water resources and livelihoods in some regions.

“Discussions of geoengineering are gaining ground recently, so it’s important to understand any unintended consequences,” says study co-author Chien Wang, a senior research scientist at MIT’s Center for Global Change Science and the Department of Earth, Atmospheric, and Planetary Sciences. “Our work is the first in-depth analysis of ocean fertilization that has highlighted the potential danger of impacting rainfall adversely.”

To investigate the impact of enhanced DMS emissions on global surface temperature and precipitation, the researchers used one of the global climate models that the Intergovernmental Panel on Climate Change (IPCC) uses, which simulates the evolution of and interactions among the ocean, atmosphere and land masses. Running simulations that compared two scenarios—one, known as RCP4.5, that the IPCC uses to project greenhouse gas concentrations, aerosol emissions and land use change based on policies that lead to moderate mitigation of greenhouse gas emissions over the course of the 21st century; the other identical to RCP4.5 except DMS emissions from the ocean were increased to the maximum feasible levels (about 2.5 times higher)—they found mixed results.

The simulations showed that enhanced DMS emissions would reduce the increase in average global surface temperature to half that of the RCP4.5 scenario, resulting in a net increase of 1.2° Celsius by 2100. But the cost would be a substantial reduction in precipitation for some regions.

“Generally, our results suggest that the cooling effect associated with enhanced DMS emissions would offset warming across the globe, especially in the Arctic,” says the study’s first author Benjamin Grandey, a senior postdoctoral associate in Wang’s group who configured the model simulations and analyzed the data. “Precipitation would also decline worldwide, and some parts of the world would be worse off. Europe, the Horn of Africa, and Pakistan may receive less rainfall than they have historically.”

Grandey and Wang warn that the lower rainfall could reduce water resources considerably, threatening the hydrological cycle, the environment and livelihoods in the affected regions.

The researchers hope their investigation—summarized in a video produced by Grandey—will inspire further studies of more realistic ocean fertilization scenarios, and of the potential impacts on marine ecosystems as well as human livelihoods. Further research will be needed, they say, to fully evaluate the viability of ocean fertilization as a geoengineering method to offset greenhouse gas-induced warming.

The study was funded by the Singapore National Research Foundation through the Singapore-MIT Alliance for Research and Technology Center for Environmental Sensing and Modeling, and grants from the National Science Foundation, Department of Energy, and Environmental Protection Agency.

Photo courtesy of Jacques Descloitres/NASA Goddard Space Flight Center.