Work

Abrupt stream acidification and metal mobilization from permafrost degradation

Year: 2026

Type: article

Abstract: Stream chemistry and ecosystem function are being transformed by abrupt acceleration of sulfide-mineral oxidation in permafrost-underlain headwater catchments of the Yukon and Mackenzie river basins-the two largest (sub)Arctic rivers in North America. Over the past decade, dozens of acidic (pH ~3) seepages have emerged in these headwaters, causing vegetation dieback and mobilizing metals at acutely toxic concentrations in receiving streams. Acid generated during sulfide-mineral oxidation also accelerates carbon dioxide emissions by driving carbonate-mineral dissolution. Downstream (sub)Arctic rivers show statistically significant multidecadal increases in sulfate concentrations, yet their metal concentrations remain stable because of attenuation and dilution processes. Headwater stream acidification signals a major perturbation in metal, carbon, and sulfur cycling linked to permafrost thaw with far-reaching consequences for water resources, northern communities, ecosystem health, and Earth's biogeochemical future.

Source: Science

DOI: 10.1126/science.aea2898

Authors: Elliott K. Skierszkan, Andras J. Szeitz, Matthew B.J. Lindsay, Sean K. Carey

Institutions: University of Saskatchewan, Carleton University, McMaster University

Language: English

Topic: Climate change and permafrost

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Climate action, Clean water and sanitation

Open Access status: green

Funders: Canada First Research Excellence Fund, Natural Sciences and Engineering Research Council of Canada, Environment Canada, Global Water Futures