The Permafrost Climate Feedback
Arctic and Boreal ecosystems contain a huge stockpile of organic matter. High latitudes are warming twice as fast as the rest of the planet, and this abrupt defrost is triggering landscape collapse and the decomposition of permafrost carbon and nitrogen. We are using the water chemistry in stream networks around the Toolik Field Station to identify where and how permafrost is degrading and what happens to the carbon and nutrients liberated by thaw.
- How will carbon and nutrient balance in the permafrost zone change as the Arctic and Boreal thaw?
- How will permafrost degradation influence local ecosystems (distribution of vegetation and changes in aquatic food webs) and global teleconnections (biogeochemistry of the Arctic Ocean and the global climate system)?
- How much of this change can be avoided if human greenhouse gas emissions are reduced?
Freshwater Landscapes in the Anthropocene
Human survival depends on access to clean water but agriculture and urbanization dump hundreds of millions of tons of fertilizers and other pollutants into freshwater ecosystems every year. This causes eutrophication, toxic cyanobacteria blooms, and expansive hypoxic dead zones that damage ecosystems and undermine human food and water security. Anthropogenic pressures on aquatic ecosystems are expected to intensify due to population growth and increasing meat consumption through the middle of the century. To address this crisis, we are developing new ecohydrological tools to assess the capacity of catchments to retain and eliminate pollutants. Using data from agricultural and urban landscapes in western France and the Intermountain West, we are testing biogeochemical proxies of where water goes, how long it stays there, and what happens along the way. We are developing new approaches to managing human activity with a large group of ecohydrologists from the U.S., Europe, Central America, China, and Africa.
- What determines a catchment’s resilience to human disturbance?
- Why do some catchments retain or remove nutrients and contaminants, while other readily export inputs to rivers, lakes, and estuaries?
- How long will it take ecosystems to recover after we reduce pollutant loads?
Combining Expert Opinions to Inform Policy
Many environmental issues such as climate change, eutrophication, and air pollution are both complex and time sensitive. Delaying action can cause ecological disaster and massive human suffering, but there is often insufficient or conflicting evidence. When data are sparse but management decisions are pressing, expert judgement has long been used to constrain possible system response and risk of dangerous or undesired outcomes. We use expert assessment, a technique for combining many subjective estimates, to distill diverse and disparate types of scientific knowledge into policy-relevant summaries. The approach is similar to the concept of ensemble models where multiple estimates built on different assumptions and data provide a more robust estimate and measure of variance. Because the experimental units are individual researchers, each data point represents an integration of quantitative knowledge from modeling, field, and laboratory studies as well as qualitative information based on professional opinion and personal experience with the system. We are currently using expert assessment to explore the possible responses of subsea permafrost and global wildfire to environmental change. We are developing and administering surveys to identify sources of uncertainty and quantify the distribution of current expert opinion.
- How can you combine and compare knowledge from different fields generated in different ways?
- What information is reliable when trying to predict responses of complex systems?
- What new research would most reduce uncertainty regarding urgent environmental problems?
Improving Public Understanding of the Environment
We can only care for what we know about. Despite widespread interest in environmental and human health, many people lack quality information on environmental issues. For example, can you identify the top three most pressing environmental crises (click here to see if you got it right)? Our lab group is trying to improve how environmental science is taught, spoken, blogged, and reported by evaluating the tools we use to teach science, organizing citizen science, and by generating original, non-technical content. In one project, we have analyzed 600 images of the global water cycle, noting how human activity is depicted (or not) in each diagram. In another, we partnered with 150 citizen scientists to sample all the tributaries to Utah Lake. We collaborate with partners from the social sciences and humanities to learn how best to communicate complex science in an intelligible and palatable way.
- How can we better educate everyday citizens about environmental issues?
- How can we get this information to elementary and secondary teachers?
- How can we reach cultural groups that have previously been resistant or skeptical of scientific evidence?