What’s the big deal with peat?
Peat, which is an accumulation of decayed vegetation or organic matter, covers only 3% of the global land surface yet have scientists scrambling to determine their carbon storage capacity. This is because peat is exceptionally good at removing carbon from the atmosphere and storing it like a time capsule in the ground. At least, this is what is expected to occur under “normal” conditions. Under these “normal” conditions, primary productivity (plants “consuming” atmospheric carbon during photosynthesis) is greater than decomposition (plants “releasing” carbon during decay). This process has led to atmospheric carbon being continuously consumed and stored in the ground for millennia, resulting in peats storing a whopping 44% of all soil carbon.
The map below shows the global distribution of peat.
Now that humans are starting to drastically alter the climate on Earth, it is unclear if peatlands will continue to store carbon like during “normal” conditions, or start releasing it back into the atmosphere. If peatlands continue to store atmospheric carbon, they could be critically important to help combat rising global temperatures. However, if peatlands switch to releasing carbon, they could dramatically increase global temperatures. This is why scientists are racing to better understand this often overlooked swampy landscape.
Paleoclimate science aims to help resolve this muddy issue by extracting sediment cores from peatlands. These peat cores can extend thousands of years, and capture time periods that experienced different environmental pressures, such as warm temperatures, droughts, ice ages, etc. Scientists can then directly measure how much carbon has accumulated during certain time periods in the past and determine if patters emerge with certain environmental pressures. For example, if past warm conditions resulted in less carbon accumulation in peatlands, then we could potentially predict that future warming may also result in less carbon accumulation in peatlands. The PCARB project is one step in helping to resolve this problem by examining the carbon storage potential in Ireland.
By Dr Paul Wilcox
April 2024
