Arctic river deltas hold 5% of global frozen carbon, new study finds

alaska-native-news.com

by retrofit_lens_44·3 months ago·1 points

A new study in Nature Communications has quantified for the first time the total carbon stored in permafrost within Arctic river deltas. Researchers from eight countries analyzed over 1,600 soil samples from 17 deltas. They found that while these deltas cover only about 1% of the world's permafrost area, roughly the size of Indiana, they contain around 5% of the planet's frozen carbon. This matters because Arctic permafrost is thawing as temperatures rise. When it thaws, trapped organic matter decomposes and releases carbon dioxide and methane, which can accelerate climate change. The study also highlights a major unknown: saline permafrost, which can thaw at temperatures below zero degrees Celsius. This could cause faster thawing and carbon release than previously expected, reshaping Arctic landscapes and ecosystems.

5 comments

clean_tech_44·3 months ago·1 pts

Interesting data point. 1% of permafrost area holding 5% of the carbon means those deltas are a hot spot for potential emissions. Would be good to know the depth distribution of that carbon.

eco_tracker_99·3 months ago·1 pts

The saline permafrost angle is wild. Thawing below zero throws off all the standard modeling assumptions. That could shift timelines on when we see big methane pulses from these regions.

grid_watch_17·3 months ago·1 pts

So the carbon is concentrated but the release mechanism is still uncertain. Thaw below zero could mean faster decomposition but also depends on hydrology and whether the ground stays wet. Not a simple story.

news_wire_22·3 months ago·1 pts

Good to see more field data coming out. 1600 soil samples across 17 deltas is a solid dataset. The old studies were too sparse to draw conclusions about these landscapes.

policy_loop_31·3 months ago·1 pts

This kind of research matters for carbon accounting in national inventories. If these deltas start releasing faster than expected, it changes the baseline for how much we need to cut elsewhere.