Peatlands critical against climate change

Peatlands critical against climate change

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Murdoch University Professor Davey Jones during research measuring carbon dioxide emissions on 16 peatlands in the United Kingdom and Ireland.

Murdoch University Professor Davey Jones during research measuring carbon dioxide emissions on 16 peatlands in the United Kingdom and Ireland.

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Peatlands are wetland ecosystems where the constant presence of water prevents plant material from fully decomposing.

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GLOBAL peatlands store more carbon than is naturally present in the atmosphere but are under pressure from drainage-based agriculture.

New research shows how re-wetting these areas can turn them from greenhouse gas emitters into carbon sinks.

Peatlands are wetland ecosystems where the constant presence of water prevents plant material from fully decomposing.

New research from Murdoch University reveals that peatlands - huge expanses of partially decayed vegetation - present a major opportunity to arrest natural greenhouse gas emissions.

"We estimate that for every 10 centimetres we raise water levels in peatlands, we can reduce the net warming impact the equivalent of at least three tonnes of CO2 (carbon dioxide) per hectare, per year," said Murdoch University professor Davey Jones.

"When you consider European peatland covers 51 million hectares alone, the impact of better managing these areas is significant."

The research outlines that raising water levels further would continue to have a net cooling effect until the water table depth is within 10cm of the surface of the peat.

Peatlands are critical for preserving global biodiversity, providing safe drinking water, minimising flood risk and helping address climate change by storing more carbon than all other vegetation types in the world combined.

"There is a big focus on 'negative emission' strategies to offset the world reliance on fossil fuels, but the challenge of reducing the emissions from organic soils can't be overlooked," professor Jones said.

"Global peatlands store more carbon than is naturally present in the atmosphere.

"So, if we continue to drain and develop them, we face a massive influx of harmful gasses.

"Managed correctly, the opposite is true and they can become carbon sinks."

Most studies of peatland management for climate mitigation have focused on restoring them to functional wetland systems.

However, while these changes would establish significant carbon sinks, the loss of economic income has precluded their large-scale implementation.

This research presents a sustainable path forward where partial re-wetting reduces emissions and, where more wetting is possible, creating a net cooling effect.

"Our results indicate that the development of locally appropriate mitigation measures within agricultural peatlands could deliver substantial emissions reductions and that really needs to happen now," professor Jones said.

He said that water levels needed to be raised rapidly to avoid further oxidisation of peatlands and achieve net zero emissions on the 30-year timescale of the Paris Agreement.

The development of water-tolerant, economically viable crops suitable for cultivation in peatland areas should also be a high priority to allow agriculture to continue sustainably in these areas.

The research measured CO2 emissions on 16 peatland locations across the United Kingdom and Ireland.

These sites encompass the main temperate peatland types and a diverse range of land use, from near-natural and restored wetlands to extensive and intensive grassland and cropland.

Professor Jones is part of the Food Futures Institute at Murdoch University whose work spans controlling viral pathogens - including COVID-19 - in agricultural, freshwater and marine ecosystems, promoting carbon sequestration in agricultural systems and improving nutrient use efficiency in cropping systems.

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