Peatlands keep a lot of carbon out of Earth's atmosphere, but that could end with warming and development

Peatlands are a type of wetland where dead plant material doesn’t fully decompose because it’s too soggy. In these ecosystems, peat builds up as spongy dark soil that’s sometimes referred to

as sod or turf. Over thousands of years, yards-thick layers of peat accumulate and trap huge amounts of carbon, helping to cool the climate on a global scale.  But that might not be true

for much longer. Warming temperatures and human actions, such as draining bogs and converting them for agriculture, threaten to turn the world’s peatlands from carbon reservoirs to carbon

sources.

Humans have used peat for centuries as a fuel, and also to flavour whiskey.

But now climate change is altering those conditions. For example, in many regions of the Arctic, rapid permafrost thawing promotes microbial activity that releases greenhouse gases into the

atmosphere. These microbes feed off carbon-rich peats that were once frozen.

Massive peatland fires also contribute. Recent wildfires like those in Russia are known to release as much carbon in a few months as total human carbon dioxide emissions in an entire year.

And these fires are especially tricky to put out. Embers within the dense organic matter can reignite many months or even years later.

Predicting how much carbon will be released from peatlands worldwide is hard to do, especially because no models can adequately represent these ecosystems and the many factors that influence

their carbon balance.

Even though models are not ready, decisions need to be made now about how to manage peatlands. That’s why we surveyed experts as a first step towards predicting the fate of peat carbon

worldwide.

Based on their responses, we estimate that 100 billion tons of carbon could be emitted from peatlands by 2100 – an amount equivalent to about 10 years of emissions from all human activities,

including burning fossil fuels and clearing forests. The experts we consulted have not reached a consensus, and our estimate is highly uncertain: Net changes in peat carbon over the next 80

years could range from a gain of 103 billion tons to a loss of 360 billion tons.

Not every region will be affected the same way. High-latitude peatlands might see an increase in carbon storage under a warming climate because of increased plant growth and greater peat

accumulation. Tropical peats, on the other hand, are more likely to dry out and burn due to warming temperatures and human activity. These factors and human choices about peatland use will

affect whether these areas become carbon sources or sinks in the future.

Despite the uncertainty in our findings, we believe our results show that peatlands should be included in climate models, and that nation should take steps to preserve them.

Peatlands should also be considered in integrated assessment models that researchers use to understand climate change impacts and options for mitigating them. Models that project future

socioeconomic change and carbon emission pathways could help develop incentives such as peatland carbon pricing and sustainable use practices. This would change the way these ecosystems are

valued and managed.

The first step, however, is to raise awareness around the world of this precious natural resource and the consequences of continuing to exploit it.