Atmospheric methane plays a major role in controlling climate and its atmospheric burden has more than doubled since 1850, yet contemporary methane trends (1982-2017) have defied explanation. Methane concentrations stabilized in the early 2000s and began increasing again in 2007. Neither the stabilization nor the recent growth are well understood, as evidenced by multiple competing hypotheses in the literature over the past 2 years. Explanations for the increases and stabilization have invoked changes in tropical wetlands, livestock, fossil fuels, biomass burning, and the methane sink. This talk will address three main questions: 1) "What do we know about sources, sinks, and underlying processes driving observed trends in atmospheric methane?", 2) "How will global methane respond to changes in anthropogenic emissions?", and 3) "What future observations could help resolve changes in the methane budget?"
This talk will draw on results from a recent open-access paper: Turner*, Frankenberg*, & Kort*, PNAS (2019). The paper is available on the PNAS website or at: https://doi.org/10.1073/pnas.1814297116.
About The Speaker:
Alex Turner is a Miller Postdoctoral Fellow at UC Berkeley working with Ron Cohen and Inez Fung. He works on a variety of topics related to atmospheric chemistry, the carbon cycle, inverse modeling, and remote sensing. Broadly, his research focuses on understanding how carbon cycles through the various reservoirs in the earth system (e.g., the atmosphere, ocean, and biosphere). He completed his PhD in atmospheric chemistry in 2017 at Harvard where he worked with Daniel Jacob and his BS in mechanical engineering in 2012 at CU Boulder where he worked with Daven Henze. He was supported by a NOAA Hollings Scholarship and a DOE CSGF fellowship during his undergraduate and graduate work, respectively.
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