How will climate change affect organic matter exported from peat?

Peatlands cover only 2.8% of the Earth but store 50% of the global soil carbon pool and 10% of the world’s freshwater. Peatland rivers are significant sources of fluvial carbon (as dissolved organic carbon (DOC), a component of organic matter) and concentrations in the northern hemisphere have doubled in the last 20 years. Climate change has been cited as one of the possible reasons for the observed increase, and prolonged drought is known to increase DOC production from peat, but the effect of climate change on organic matter composition is unknown. Temperature increase is likely to affect the rate of the processing of organic matter in water, and therefore the greenhouse gas (GHG) emissions, further contributing to climate change. In-stream emissions from water bodies are under-represented in the Intergovernmental Panel on Climate Change (IPCC) reports. It is important to understand the relationship between climate and organic matter composition and processing to allow models of future climate change to include the potential for positive feedback as GHG emissions from water increase.
There are also implications of this increase in DOC concentration for water companies, as the water draining peatlands has high DOC and therefore dissolved organic matter (DOM) concentrations, resulting in highly coloured water.3 When water colour peaks become too severe water companies have to invest tens of millions of pounds in capital for every new treatment plant, plus the additional expense of running those plants. For the IPCC, water companies, policy makers and society there is an urgent need to understand how climate change will affect the composition, processing and treatability of DOM, and the outcomes of this project will help to optimise water treatment performance to deal with threats posed by changes in DOM composition as a result of climate change.
This project will explore an interdisciplinary approach to quantify the effect of climate and land-use change on DOM composition and processing, and therefore potential GHG emissions.