A project to investigate the potential impact of global warming on Arctic ecosystems, and whether this will lead to less carbon being held in the soil, has received almost £800,000 funding from the UK Natural Environment Research Council (NERC).
A warming Arctic may switch from being a net sink for atmospheric carbon dioxide into a source, thus acting as a positive feedback on warming.
The three and a half year project, PRIME-TIME, will be led by Phil Wookey, Professor in Ecosystem Science in Heriot-Watt's School of Energy, Geoscience, Infrastructure and Society, EGIS. It will challenge widespread current assumptions that, as temperatures rise, increasing plant productivity in northern ecosystems will act as a net sink for atmospheric CO2 and constitute a ‘negative feedback' on global warming.
Professor Wookey and colleagues from the Universities of Edinburgh, Exeter, Glasgow, Manchester, Stirling and Uppsala (Sweden), will instead investigate whether the process of ‘soil respiration' will, under warmer conditions, actually release more CO2 to the atmosphere, cancelling-out, or exceeding, any effects of increased plant productivity. Soil respiration results from the breakdown (decomposition) of existing soil organic matter, as well as the activities of plant roots and their associated microbial communities,
“Soil respiration is one of the major fluxes in the global carbon cycle, emitting approximately 12 times more CO2 to the atmosphere every year than fossil fuel combustion and cement manufacture combined. It is highly sensitive to changes in temperature and moisture, as well as to changes in plant productivity and species composition. We need to understand the drivers of this process in order to predict how it will change in the future.”
“Processes in the Arctic deserve particular emphasis because this region is warming faster than most of the planet, and Arctic and boreal regions, together, contain around a third of the total global soil carbon stocks.
“A warming Arctic may switch from being a net sink for atmospheric carbon dioxide into a source, thus acting as a positive feedback on warming.”