Grant: Advancing Climate Change Science in Canada

High latitude cold regions, including Arctic and northern areas of Canada, are warming more than twice as fastas the rest of the planet, with the greatest warming occurring during the winter. Given that a major processresponsible for carbon dioxide (CO2) emissions, microbial respiration, increases with warming even atsub-zero temperatures, winter is a critical period for carbon cycling. Consequently, CO2 emissions during thenon-growing season (NGS; fall, winter, spring) are expected to increase as the climate warms. However, thereis large uncertainty in estimates of current NGS CO2 emissions from cold region ecosystems. Canada'stemperate to subarctic wetlands and permafrost peatlands hold large stores of carbon which are susceptible toloss under future climate warming scenarios. Therefore, understanding the factors which regulate the processescontrolling greenhouse gas emissions during the NGS is critical for predicting the fate of these vulnerablecarbon stocks and for creating climate adaptation and mitigation strategies. With a focus on these criticalecosystems, we bring together Canadian leaders from multiple disciplines from across universities with federalgovernment scientists and policy makers to determine the drivers of NGS carbon cycling, developprocess-based environmental models, and estimate CO2 emissions. In doing so, we will address the knowledgegaps on NGS emissions to provide data and tools to evaluate the impact of winter warming mitigation incontrolling carbon losses from pan-Canadian wetland ecosystems. Through a combination of historical datasynthesis, laboratory experiments and modelling, the proposed research will focus on 1) determining thehydrological and climatic factors driving microbial NGS carbon cycling; and 2) integrating the information anddata gained into models describing the underlying processes controlling NGS emissions for incorporation intothe Carbon Budget Model of the Canadian Forest Sector (CBM-CFS). This will advance our ability to trackand predict carbon fluxes in cold regions wetland ecosystems and make improved, evidence-basedrecommendations to estimate winter carbon losses and evaluate mitigation strategies.