QCFACH

Quantifying Climate Feedback From Abrupt Changes in High-Latitude Trace-Gas Emissions

Duration:07/2008 - 07/2011
Award Amount:$89,999 to $560,000

Participants
Purdue University, Earth & Atmospheric Sciences and Agronomy: Qianlai Zhuang
MIT: A. Schlosser
Marine Biological Laboratory: Jerry Melillo
University Alaska Fairbanks: K. Walter

Project Objectives

Our overall goal is to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically forced climate warming, and the extent to which these emissions provide a strong feedback mechanism to global climate warming. This goal is motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes in the extent of wetlands and lakes, especially thermokarst (thaw) lakes, over the Arctic. Through a suite of global model experiments that encapsulate the fundamental processes governing methane emissions – as well as their coupling to the global climate system -we intend to test the following hypothesis:

There exists a climate warming threshold beyond which permafrost degradation becomes widespread and thus instigates strong and/or sharp increases in methane emissions (via thermokarst lakes and wetland expansion). These would outweigh any increased uptake of carbon (e.g. from peatlands) and would result in a strong, positive feedback to global climate warming.