Natural Methane Emissions in a Changing Arctic - Implications for Climate and Environment

Natural emissions of methane have received much attention over the last decade due to the documented increase of methane in the atmosphere and high global warming potential relative to CO₂. Over the past few decades the Arctic has been warming approximately four times faster than the rest of the planet, driving a pressing need to assess the current and future vulnerability of various natural methane sources. In the Arctic, vast amounts of methane is stored in soils and permafrost or is being generated as permafrost thaw continues. Additionally, there are large stores of methane in Arctic gas hydrates, a solid form of concentrated methane and water, and in numerous settings, including deep-water marine areas, on continental shelves hosting relict subsea permafrost and gas hydrate, in and beneath onshore permafrost, and likely beneath the Greenland Ice Sheet. Continued climate warming is making methane leakage more likely. Even deeper conventional gas reservoirs could leak methane as the overlying permafrost degrades.

With this Research Topic, we aim to bring together research addressing diverse aspects of Arctic methane and its role in the global carbon cycle, therefore furthering our understanding of complex high-latitude methane generation/mobilization processes and their interaction with the climate and environment. We encourage submissions addressing the formation, storage, cycling, transport, release and budgets of methane through the Arctic geo-, hydro-, cryo- and atmosphere and relevant geologic, physical, chemical, and biological processes. Studies may be at spatial scales ranging from laboratory samples of permafrost soils to the entire Arctic and covering the geologic past, the present, or model-based predictions for the future.

This Research Topic is dedicated to profiling the current state-of-knowledge regarding methane emissions under a changing climate, both from marine and terrestrial systems in the Arctic. It will contribute new understanding to Arctic methane systems and the consequences for climate and environment. Potential topics include, but are not limited to, the following:

• Methane in the geosphere: subsurface thermogenic, (a-)biogenic and methane sources and sinks;
• Methane in the hydrosphere: methane processes and budgets in marine and high-latitude lacustrine settings;
• Methane in the cryosphere: methane dynamics in ice sheets, permafrost and gas hydrates;
• Methane in the atmosphere: methane sources, sinks, and budget in the atmosphere;
• Microbial cycling of methane: the role of microbes in methane budgets; and
• Past methane histories: past methane processes and budgets as analogues for future climate scenarios.

We welcome contributions based on both empirical data and numerical modelling, and manuscripts that integrate the different themes. Thorough Review Articles are also welcome.