Potential impacts of mercury released from thawing permafrost
Abstract
Mercury (Hg) is a naturally occurring neurotoxin that bonds with organic matter. Frozen organic matter in permafrost represents the largest reservoir of Hg on the planet. We modified the Simple Biosphere/Carnegie-Ames-Stanford Approach terrestrial biogeochemistry model (SiBCASA) to include mercury biogeochemistry. We then estimated future releases of Hg from thawing permafrost for a low emissions scenario close to the 2 °C target of the Paris Accord and a high emissions scenario of unconstrained fossil fuel burning. The high emissions scenario showed annual atmospheric Hg emissions from thawing permafrost peaking above current anthropogenic emissions. Hg concentration in the Yukon River barely increases for the low emissions scenario, but exceeds the Environmental Protection Agency (EPA) maximum limits for the entire thawed season for the high emissions scenario. Calculated Hg concentration in fish never exceed EPA maximum limits for the low emissions scenario, but for the high emissions scenario, it exceeds EPA limits within a hundred years. Our results indicate minimal risks to water and food supplies for the low emissions scenario, but high risks for the high emissions scenario.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B51I2352S
- Keywords:
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- 3339 Ocean/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 0409 Bioavailability: chemical speciation and complexation;
- BIOGEOSCIENCES;
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0461 Metals;
- BIOGEOSCIENCES