Methane is one of the most important greenhouse gases. Yet, the sources and sinks of atmospheric methane are poorly constrained. Recent evidence suggests lakes represent one of the most important methane sources, but it is unclear how representative the available data is. Moreover, the variability in space and time of lake methane flux is also unclear, which hamper development and validation of models. Therefore, current lake methane flux estimates are uncertain, and although we expect changed lake fluxes as feedbacks from climate change, we lack means of quantifying and predicting these feedbacks. Such limited knowledge about one of the largest methane sources is a societal problem, because under the Paris agreement, we need to know present and future emissions of all greenhouse gases as they all affect temperature. We also need to know how the extensive natural greenhouse gas emissions will develop in a warmer climate to design appropriate climate mitigation targets. The society also need more effective methods for measuring greenhouse gas fluxes.
The aims of the project include to better quantify methane emissions from lakes, assess how sensitive these fluxes are to changing environmental conditions, and to develop models to predict future lake methane emissions. The METLAKE studies of how lake methane emissions are regulated, and how sensitive they are to global warming, are important to assess how the fluxes will develop and contribute to the future climate. A key is to generate extensive high-quality flux measurements to map spatiotemporal variability and for developing models that are well-validated relative to real measurements. Other long-term aims, with implications beyond the specific project, is to develop supplementary approaches to measure greenhouse gas emissions for use both in lake studies and more broadly in nature and society.
