November 22, 2018
It is common knowledge now that humans have created a climate disaster. Until we come up with a way to reverse climate change and its effects, we are relying on natural carbon sinks such as forests and oceans to suck carbon dioxide out of the atmosphere. But a study, published in the journal Proceedings of the National Academy of Sciences, has some shocking revelations for us that claims– if climate change remains unchecked, these natural sinks may soon start emitting the greenhouse gas instead.
Peatlands may become carbon emitters
As already explained, systems that could suck carbon dioxide out of the atmosphere are known as natural carbon sinks. Among them, the peatlands with a carbon dioxide-rich type of soil called peat are the most efficient natural carbon sink on the planet.
When undisturbed, they store more carbon dioxide than all other vegetation types on Earth combined. But when the peatlands are drained and deforested, they can release nearly six per cent of global carbon dioxide emissions each year, according to the researchers.
“Global peatlands cover only about three per cent of the global land area but hold around 30 per cent of the earth’s soil organic carbon,” said author Zhuang Qianlai, a professor of earth, atmospheric and planetary sciences at Purdue University, as stated on university’s website.
For the study, the team looked at peatlands in the Peruvian Amazon to try to find out if a large amount of peat carbon can be released under a warmer climate.
According to an earth systems model spanning from 12,000 years ago to 2100 AD, the relatively small basin could lose up to 500 million tonnes of carbon by the end of this century.
That is about five per cent of current global annual fossil fuel carbon emissions, or 10 per cent of US emissions, being spit back out into the atmosphere.
Higher temperatures lead to more peat carbon loss
The study showed that higher temperatures led to more peat carbon loss, although increased precipitation slightly enhanced the build-up of peat carbon over long timescales. Together, the carbon loss from peatlands to the atmosphere would be increased.
“If the area we looked at could represent the whole Amazonia or tropical peatlands, the loss of peat carbon to the atmosphere under future climate scenarios should be of great concern to our society,” Zhuang said.
“Agricultural intensification and increasing land-use disturbances, such as forest fires, threaten the persistence of peat carbon stocks,” he said.
“These peatland ecosystems may turn into carbon sources instead of sinks unless necessary actions are taken,” he added.