Limiting the Risk to Ecosystems and Humanity of Methane Surges in Arctic Coastal Seas: An Analysis of Methods and Costs

Abstract:

For several decades, international expeditions have documented increasing quantities of methane leaking from seabed permafrost in the shallow East Siberian Sea and reaching the atmosphere. As Arctic heating accelerates, a serious methane burst from the East Siberian Arctic Shelf appears increasingly likely within this decade. Though shorter-lived in the atmosphere than CO2 , methane is close to 100 times as potent a greenhouse gas in the short term. A large, sudden release of methane could so destabilize climate systems that it could

constitute a global emergency for humanity.

While pathways to reduce atmospheric CO2 levels are becoming widely understood, ways to reduce methane are not as well documented, even though methane levels in general have increased five times faster than CO2 levels.

This paper examines the risks of methane increases, both gradual and sudden, through maps of recent global methane emissions; analysis of data from investigations to the ESAS; computer modeling; and hothouse precedents in geological history. We then compare efficacy and cost-effectiveness of three pathways to restore and maintain safe methane levels: aerosol-based methane removal, solid-based removal, and reduction of methane emissions. Finally, we consider possibilities for funding and implementing a program to reduce methane levels.

We found that atmospheric methane removal—using aerosols that catalyse oxidation of methane into CO2 and water—has the highest chance of successfully keeping methane levels in a safe range even if a methane burst occurs. It would also cost the least. Solid-based methods, requiring airflow past solid materials such as zeolites, would cost 1,000 times more. To control methane emissions at their source would require protecting a significant portion of the surface of the seabed and cost at least a million times more.

To reduce global methane to a safe level even in the face of a methane burst is urgent. It is feasible using tested methods, at a cost financeable by individual philanthropists. Since no other institution has methane reduction as a mission, we are launching a new, non-profit Global Methane Removal Program to handle research and implementation.