Climate models upon which climate change projections, risk assessment, mitigation strategies, and international negotiation are based have long ignored biology. In her doctoral dissertation, Elsa Abs develops a new generation of global carbon cycle (the core driver of climate change) models that feature the soil microbiome explicitly. From tropical forests to arctic peatlands, soil microbes respond to warming by breathing more, or less, CO2 – and this might cause a huge feedback of life on climate. Under the co-advising of UMI director Regis Ferriere and UA professor Scott Saleska, Elsa Abs (pictured) set up to find out.

What makes Elsa Abs’ work ground-breaking is that her models include the capacity that microbial populations have to evolve, in the Darwinian sense, and adapt ‘in real time’ to climate change. Evolutionary adaptation can aggravate, buffer, or even revert the change in microbial respiration predicted by simpler models, without evolution. Another fascinating aspect of the problem tackled by Elsa is that, in her model, the target of evolution is cooperation among microbes. This takes the form of the production by individual microbes of a public good—chemical compounds that help them collectively decompose the organic matter that they consume to grow and reproduce. It tuns out, models predict, that climate warming often drives the evolution of more cooperative microbes. This is bad news for us, because stronger microbial cooperation means more respiration, and eventually more CO2 flowing back in the atmosphere. 

At Evolution 2018, held August 19-23 in Montpellier, France, Elsa Abs presented her results with an attendance of more than 3,200 participants. This was an opportunity for Abs to interact with researchers and fellow students from all around the world. Back in Tucson, she is wrapping up her doctoral thesis, to be defended in January 2018. Strategically, Abs’ project is important to the UMI. The project establishes a strong theoretical component in the long-term collaboration that the UMI entertains between UA Biopshere 2 and the CNRS-ENS Ecotron. The project also links the UMI to the UA Ecosystem Genomics Initiative – an inter-department, inter-college endeavor led by Scott Saleska. Future development will fuel the arising CNRS interdisciplinary program Planète A on sustainability objectives in response to climate change.