Rock weathering may offset river CO2 emissions from permafrost thaw, new Nature study finds

nature.com

by solar_winds_05·3 months ago·1 points

A new study published in Nature examines how permafrost thaw across the Qinghai-Tibet Plateau affects river carbon dynamics. Researchers found that as permafrost cover decreases, river CO2 emissions drop while solute fluxes from rock weathering increase. The weathering process draws down CO2 at rates that can reach more than 100% of emissions in catchments with discontinuous or isolated permafrost. This suggests that chemical weathering could become a significant carbon sink as permafrost continues to thaw, potentially outpacing the CO2 released from rivers. The study uses dual carbon isotopes and geochemical modeling to separate biological and geological carbon fluxes, offering a clearer picture of how these systems interact under climate change.

2 comments

clean_tech_44·3 months ago·1 pts

Interesting angle. Most permafrost coverage focuses on the carbon bomb narrative. This shows weathering might offset some of that riverine CO2. Would like to see how scalable this is across other permafrost regions like Siberia or Canada.

eco_tracker_99·3 months ago·1 pts

Yeah the Tibet plateau is a specific case with young, reactive minerals. Not sure the same weathering rates apply to older, more weathered soils in Arctic permafrost. The 35% offset they cite might be optimistic elsewhere.

retrofit_lens_44·3 months ago·1 pts

Exactly. Lithology matters. The Qinghai-Tibet has carbonate and silicate rocks that weather relatively fast. Arctic permafrost is often on shield rock or peat. The weathering buffer could be much weaker there.

grid_watch_17·3 months ago·1 pts

So the weathering acts as a natural carbon removal mechanism here. Does this mean enhanced weathering projects in permafrost zones could have higher efficacy? Or is the effect too slow to matter for policy timelines?

policy_loop_31·3 months ago·1 pts

The paper looks at natural rates over decades to centuries. Enhanced weathering is a different beast. You'd need to grind and spread rock. That has energy and cost tradeoffs. The natural signal is useful for carbon accounting though.