Vast stretches of peat stretches across the north of our planet, accumulated organic material too wet to decompose. Although peat bogs represent only 3 percent of the total earth’s surface, they store a third of their earth’s carbon. And climate scientists are worried: As the Arctic warms, they are drying up and releasing massive amounts of carbon. People accelerate this process by draining peatlands and transforming them into agricultural fields, releasing even more greenhouse gases.
In a recent one letter in the newspaper Advanced Science, Researchers have put a massive number on the climatic effect that agriculture in these areas has had: Modeling the historical land use, they calculated that between the years 1750 and 2010, cultivated northern peatlands released 40 billion tons of carbon.
“When peat dries – that is, people dig drainage ditches to lower the water level of a peat to make it suitable for crop cultivation – peat soil is aerated and aerobic microbial decay of organic matter, which needs oxygen, is increased, thus resulting in the release of carbon from the turf into the atmosphere, ”main author Chunjing Qiu, of the Laboratory of Climate and Environmental Sciences of France and the University Paris-Saclay. Any new plant material that grows and dies will decay rapidly, releasing its carbon, because there is not enough water to slow down the transformation of organic matter into CO.2.
Traditionally, climate scientists have focused on the amount of carbon we can lose from deforestation, but have often investigated the effects of turning peat bogs into fields. “We didn’t always do a good job of really counting how much carbon could be lost from it land system, ”says Maria Strack, a soil scientist who studies peatlands at the University of Waterloo, but has not been involved in the research.“ Especially when we convert peatlands into cultivated land, the size of that organic stock of the land is so large that perhaps we have really underestimated the contribution of those land carbon losses to our greenhouse gas emissions. ”
Humanity, then, is transforming a critical coal well into one source of emissions. There are, of course, underlying social factors for this conversion: As the population continues to grow, nations will have to feed more people with the same amount of land. Economically, it makes sense that farmers are converting what they were once soaked into agricultural land. “It creates fairly fertile ground, but you lose your carbon at the same time,” says Chris Evans, a biogeochemist at the British Center for Ecology and Hydrology, who was not involved in the new paper. “Because a lot of carbon is lost from some of these landscapes, they’re kind of a vacant coal storage unit, really.”
Agricultural processes accelerate only that loss. The processing of dry peat allows more oxygen to penetrate it, which also encourages the transformation of organic matter into CO.2. Responsible microbes will proliferate even more if farmers add fertilizers that provide them with more nutrients. In a healthy, moist peat, the plant material it produces must attack and, once dead, be incorporated back into the soaked soil, where its carbon will be trapped for perhaps thousands of years. But on a farm, the crops that the land produces are uprooted from the land and brought up for sale.
Farmers working an actively cultivated peat irrigate it, keeping the soil at least moist enough for the plants to grow. But if the land is later abandoned and allowed to dry completely, it will turn into a fuel harmful to fires. Because peat is a concentrated coal, it burns quickly – but not like the massive conflagrations you’ll see. California o Australia. Instead of producing flames, peat smolders, burn deeper into the ground and move sideways through a landscape. Peat fires are so persistent that they can survive on land under winter as snow falls on them, only to it also pops up when the landscape melts in spring. That’s why scientists call them zombie fires. They could release it 100 times the amount of coal that a flame above the ground could.
Nature also dries up the peat bogs so that the northern lands heat up quickly. The Arctic throughout it is green as plant species walk north due to climate change. Warmer temperatures mean that storms are growing more and more common, giving sparks to ignite huge peat fires: Around the year 2100, lightning strikes in the far north. could double.
It is therefore critical to restore the peat that farmers have cultivated earlier. “Not only will you reduce your emissions from oxidation, but you’ll reduce the risk of fire,” says Strack.