Peatlands will store more carbon as planet warms, study suggests

Leicester scientist part of international study into effects of global warming on peatlands

Global warming will cause peatlands to absorb more carbon – but the effect will weaken as warming increases, new research suggests.

This effect – a so-called “negative feedback” where climate change causes effects which slow further climate change – will increase over the coming decades but will decline after 2100 if warming continues, according to an international team of 70 scientists.

Peatlands are a vital 'carbon sink', currently storing more carbon than all the world’s vegetation, and the research showed they will store even more carbon in the future than was previously believed.

In environments such as forests, carbon from dead plants decomposes and is released back into the atmosphere. But in peatlands, water slows this process and locks in carbon.

Most peatlands are in cold climates in places such as Siberia and Canada, and here warmer temperatures will lengthen the growing season for plants – meaning more plant matter falling into peat bogs.

But this initial increase in carbon storage – estimated to be about 5% – will be offset by reduced storage in tropical peatlands in places like Borneo and the Amazon region.

Professor Sue Page, Professor of Physical Geography from the University of Leicester's School of Geography, Geology and the Environment, said: "Our work highlights the fact that peatlands store huge amounts of carbon and can play a vital role in global efforts to control climate change.

“The study also highlights the vital importance of protecting intact peatlands and restoring drained peatlands, particularly in the tropics where the effects of future global warming are likely to lead to more rapid rates of peat decomposition.

“Peatland restoration efforts, such as rewetting drained and degraded peatlands, can restore the waterlogged conditions needed to prevent the release of peat carbon.

“These efforts need to be intensified if we are to avoid accelerating peatland CO₂ emissions into the future.”