Publication Date:
2023-11-08
Description:
Formed under low temperature – high pressure conditions vast amounts of methane hydrates
are considered to be locked up in sediments of continental margins including the Arctic shelf
regions[1-3]. Because the Arctic has warmed considerably during the recent decades and because
climate models predict accelerated warming if global greenhouse gas emissions continue to rise
[3], it is debated whether shallow Arctic hydrate deposits could be destabilized in the near
future[4, 5]. Methane (CH4), a greenhouse gas with a global warming potential about 25 times
higher than CO2, could be released from the melting hydrates and enter the water column and
atmosphere with uncertain consequences for the environment. In a recent study, we explored
Arctic bottom water temperatures and their future evolution projected by a climate model [1].
Predicted bottom water warming is spatially inhomogeneous, with strongest impact on shallow
regions affected by Atlantic inflow. Within the next 100 years, the warming affects 25% of
shallow and mid- depth regions (water depth 〈 600 m) containing methane hydrates. We have
quantified methane release from melting hydrates using transient models resolving the change in
stability zone thickness. Due to slow heat diffusion rates, the change in stability zone thickness
over the next 100 years is small and methane release limited. Even if these methane emissions
were to reach the atmosphere, their climatic impact would be negligible as a climate model run
confirms. However, the released methane, if dissolved into the water column, may contribute to
ocean acidification and oxygen depletion in the water column.
Type:
Book chapter
,
NonPeerReviewed
Format:
text
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