Terrestrial carbon cycling research in permafrost-affected environments
Dr Casper Tai Christiansen | Uni Research Climate ǀ Bjerknes Centre for Climate Research ǀ Bergen, Norway
Abstract The Arctic climate is currently warming twice as fast as the global average, leading to profound negative impacts on the millions of people living in the far North. However, changes in high latitude climate may also feedback and affect the global climate, possibly exacerbating climate change impacts worldwide. One of these feedback mechanisms involves old, partially decomposed, plant material that has been accumulating in cold northern soils for thousands of years.
Arctic and boreal soils contain twice as much carbon as currently found in the atmosphere. This large organic carbon pool is primarily stored in near-surface (< 3 m) soil layers, including permafrost, that are projected to undergo substantial warming during this century. Warmer temperatures promote microbial decomposition of organic matter, releasing greenhouse gases, such as carbon dioxide and methane, in the process. Thawing permafrost soils are therefore likely to enhance terrestrial greenhouse gas emissions to the atmosphere and increase lateral transport of soluble carbon compounds to aquatic systems. Thus, climate change has the potential to substantially alter tundra carbon and biogeochemical cycling – not just at the ecosystem scale but also across landscape and regional scales, with potentially far-reaching feedbacks to the global climate.
Here, I will present some of our ongoing permafrost projects across the circumpolar Arctic, and I will talk about the methods we use, as well as the obstacles we encounter, as we work to better understand the permafrost carbon feedback to climate change.