Chen Ding Team Model Predicts 16% Drop in Permafrost Carbon Export Over 40 Years
Updated
Updated · Earth.com · Jun 3
Chen Ding Team Model Predicts 16% Drop in Permafrost Carbon Export Over 40 Years
1 articles · Updated · Earth.com · Jun 3
Summary
A new hillslope model tied to China’s Hulugou basin shows spring’s sharp dissolved-organic-carbon spike comes from shallow thaw, when a small trickle is forced through carbon-rich topsoil.
By September, heavy rain drives the biggest carbon load, but deeper thaw routes water through carbon-poor layers, producing a much larger yet more dilute export.
The mechanism helps explain why the Qinghai-Tibet Plateau differs from the Arctic, where snowmelt usually makes concentration and load peak together; at Hulugou, snow is only about 3% of annual precipitation.
In a 40-year moderate-warming run, the active layer deepened from about 1.5 meters to nearly 2 meters, shifting flow downward and cutting lateral carbon export about 16% while making it nearly 25% more dilute.
That result challenges assumptions that thaw always sends more old carbon into rivers and suggests some cold-region carbon budgets may overstate downstream losses.
Why is thawing mountain permafrost trapping carbon instead of releasing it into rivers?
As the world’s permafrost thaws, why are some regions releasing less carbon, not more?
Thawing Permafrost on the Qinghai-Tibet Plateau Reduces DOC Export by 16%: Rethinking Carbon Cycle Impacts
Overview
A groundbreaking 2026 study led by Chen Ding at SUSTech reveals that thawing permafrost on the Qinghai-Tibet Plateau does not always lead to increased carbon export, challenging long-held assumptions. The research shows that while most carbon escapes as gas, some dissolves in water and moves laterally into streams. Surprisingly, the study found a projected decrease in dissolved organic carbon export with warming, offering a more nuanced view of permafrost’s role in the global carbon cycle. This discovery highlights the need to rethink how permafrost thaw impacts both climate models and river ecosystems.