Inland water greenhouse gas emissions offset the terrestrial carbon sink in the northern cryosphere | Science Advances
Abstract
Climate-sensitive northern cryosphere inland waters emit greenhouse gases (GHGs) into the atmosphere, yet their total emissions remain poorly constrained. We present a data-driven synthesis of GHG emissions from northern cryosphere inland waters considering water body types, cryosphere zones, and seasonality. We find that annual GHG emissions are dominated by carbon dioxide (
Please refer to original article for complete formulae.
teragrams of CO
2
;
) and methane (
teragrams of CH
4
), while the nitrous oxide emission (
gigagrams of N
2
O) is minor. The annual CO
2
–equivalent (CO
2
e) GHG emissions from northern cryosphere inland waters total
or
petagrams of CO
2
e using the 100- or 20-year global warming potentials, respectively. Rivers emit 64% more CO
2
e GHGs than lakes, despite having only one-fifth of their surface area. The continuous permafrost zone contributed half of the inland water GHG emissions. Annual CO
2
e emissions from northern cryosphere inland waters exceed the region’s terrestrial net ecosystem exchange, highlighting the important role of inland waters in the cryospheric land-aquatic continuum under a warming climate.