Map by Greg Fiske showing extent of the northern hemisphere tundra (yellow) and boreal (green) regions. The Arctic circle is shown by the dotted line.
- Bethany Sutherland Postdoctoral Researcher
- Jennifer D. Watts Arctic Program Director, Associate Scientist
- Brendan M. Rogers Associate Scientist
- Elchin Jafarov Senior Research Scientist
- Anna Virkkala Research Scientist
- Helene Genet Research Assistant Professor, University of Alaska Fairbanks
- Roisin Commane Associate Professor, Columbia University
- Luke Schiferl Adjunct Associate Scientist, Columbia University
- Eugenie Euskirchen Associate Professor, University of Alaska Fairbanks
- David Butman Associate Professor, University of Washington
- Josh Fisher Associate Professor, Chapman University
The Arctic-boreal region is undergoing more pronounced and rapid changes than any other area on Earth.
Wetlands are shifting, permafrost is thawing, wildfire frequency is increasing, and vegetation patterns are changing. These transformations impact many processes which regulate carbon cycling within the Earth’s systems.
Considerable effort and ingenuity have been dedicated to understanding the Arctic carbon cycle, yet substantial uncertainty remains regarding how the high latitudes will ultimately influence our changing climate. Many processes—such as changes in albedo (how much energy from the sun is reflected, instead of absorbed, by a material), plant carbon uptake, ecosystem greenhouse gas (GHG) emissions, and fire emissions—must be evaluated simultaneously. Some of these processes are likely to contribute to warming, while others may help mitigate it.
Our Work
Most previous studies have focused on determining greenhouse gas emissions in the Northern tundra-boreal region, without fully quantifying their impact on radiative forcing—a measure of the changes in the energy balance of Earth’s atmosphere. This project aims to take the next step by more deeply investigating the perturbation to Earth’s energy balance caused by terrestrial and aquatic greenhouse gas emissions, while also considering fire impacts and albedo.
(left) A permafrost-affected black spruce boreal forest, from the Caribou-Poker Creek Research Tower in Alaska. (right) Climate change in the Arctic-boreal is rapidly changing the surface albedo by driving earlier spring melt and longer snow free periods. Photos by Jennifer Watts.
We are compiling a comprehensive, top-tier assessment of the recent trends in carbon dioxide (CO2) and methane (CH4) levels in the Arctic by leveraging a variety of best practices for estimating the carbon budget. This data will be compared against measurements of trace gas collected from tall towers and aircraft to diagnose regional sources of uncertainty in carbon fluxes.
Regions in blue indicate areas that are sources of carbon, while the shades of tan to red indicate carbon sinks. Some recent model studies including those from Watts et al. (2023) and Virkkala et al. (2024) indicate that boreal forests (unless recently impacted by fire) may be a net sink of carbon, while tundra regions are closer to being net carbon emitters.
Models disagree about the magnitude of emissions from Northern Hemisphere tundra and boreal carbon ecosystems, whether they are a carbon sink or source, and how they are impacting Earth’s climate under current and future conditions. Through a multi-model analysis including bottom-up and top-down GHG estimate approaches, our study will identify areas of greater confidence and consensus in models, and apply the resulting multi-model ensemble to investigate how net GHG exchange from this region is influencing Earth’s climate.
We are also evaluating how changes in the carbon cycle and ecosystem properties (including albedo) are influencing global climate change by affecting the distribution of energy within the atmosphere.
(left) Christina Minions checking on a year-round soil CO2 emission monitoring station at a permafrost-affected tundra site in Alaska. (right) A wetland in Alaska. Photos by Jennifer Watts.
Impact
This project will enable us to identify which ecosystems are currently contributing to climate warming (or in some cases, cooling) and shed light on how these systems might respond under future climate conditions. This is especially important to the many Indigenous and local communities for whom this region is home. The Arctic is particularly sensitive to climate change, and understanding its unique radiative forcing mechanisms helps clarify how local changes can influence global climate patterns.
This work targets several of the largest sources of uncertainty impacting climate projections. By reducing uncertainty in carbon (CO2, CH4) budgets, and enhancing our understanding of ecosystem feedbacks to climate, this work will provide valuable insights into the likely future evolution of our Earth system and ultimately supports more effective and targeted climate policies that can help mitigate global warming.
This research is funded through the NASA ABoVE project.
