CBC radio interview on greenhouse gas emissions (GHG) from reservoirs

I was involved in a global synthesis of GHG emissions from reservoirs. I gave an interview on a CBC radio station about the paper and reservoir emissions in general, which you can listen to here:

Dr. Bridget Deemer and Dr. John Harrison of Washington State University were the lead and senior authors on the paper, respectively (Deemer et al. (2016) BioScience), and several of us from other countries provided data and expertise in the building of the manuscript. With data from over 200 reservoirs, including drinking and agricultural reservoirs as well as those for hydropower, we found that methane was responsible for 80% of the global warming potential of reservoirs globally. This enormous contribution from methane was directly related to the fact that methane can also be emitted via ebullition (or bubbling), which was one of the more overlooked gas emission pathways in studies of decades past. My dissertation work on methane bubbling in reservoirs (DelSontro et al. (2010) ES&T) helped bring this important component of gas dynamics in reservoirs into the spotlight. The Deemer et al. (2016) paper went a step further and found that methane emissions were positively related to the productivity of the reservoirs and thus more productive systems had overall higher global warming potentials. This means that if human population pressures, such as from agriculture and urban runoff, continue to increase the influx of nutrients and organic matter into reservoirs (as well as natural waters) that we may very well see an increase in greenhouse gas emissions from these waters as a result. These last few points I was not able to communicate in the CBC radio interview but are quite important findings from this new global synthesis. With this knowledge, we can honestly suggest that a way to mitigate climate change is to regulate the input of nutrients into our waterways. It is vital, however, that we continue to investigate greenhouse gas dynamics from reservoirs and natural water bodies because we still do not know or understand all of the drivers and mechanisms fueling their emissions. Finally, as the push for renewable and 'green' energy expands, we recommend that environmental impact assessments of large-scale hydropower projects include a greenhouse gas budgeting exercise so that potential emissions can be predicted and hopefully reduced. [Deemer et al. (2016) Greenhouse gas emissions from reservoir water surfaces: A new global synthesis. BioScience. doi:10.1093/biosci/biw117]