The alpine tundras in Colorado may look magnificent, but the thawing permafrost uncovers something surprising: they are releasing more carbon dioxide than what they store.
In a new study published in Nature Communications, researchers led by John Knowles wanted to find out whether the tundras in the Front Range may have the same phenomenon as that of the Arctic region. There, the melting frosts are causing a feedback loop.
It's All About The Microbes
To find out, the team determined the surface-to-air transfer of carbon dioxide emissions from 2008 to 2014. They obtained their soil samples from Niwot Ridge Long-Term Ecological Research site, which has been around for more than three decades.
They also conducted a radiocarbon dating to find out the age of the soil and how long it has been storing carbon dioxide.
Based on their analysis, the barren tundra landscapes do store carbon dioxide, but they are also releasing it. The problem is it gives more greenhouse than what it keeps. The reason: microbes.
Greenhouse gases remain one of the biggest contributors to climate change. Most develop due to human activity. Global tourism, for example, leads to about percent carbon dioxide emissions, which is higher than the previous estimate.
Organisms, though, including bacteria can also release carbon dioxide through their regular activity.
In this Colorado research, the team found out higher-than-usual microbial activity regardless of the season. In this specific area, too, winds can disturb the snowpack that should have provided insulation for the carbon dioxide. The sample also revealed how a part of the gas is old during winter.
As soon as the plants start to grow, and the permafrost begins to turn into water, the stored carbon then becomes part of the Earth's atmosphere.
What Does It Mean For Climate Change?
Experts believe one of the possible solutions is a carbon sink. It refers to a place that has the potential to store a significant amount of greenhouse gas or carbon. These include the swamps, Southern Ocean, and the forests since plants need them for food production.
The thawing of the permafrost may only "offset" this effect.
"Until now, little was known about how alpine tundra behaved with regard to this balance, and especially how it could continue emitting CO2 year after year. But now, we have evidence that climate change or another disturbance may be liberating decades-to-centuries-old carbon from this landscape," said Knowles.
The team wants to make it clear the carbon emission they detected still paled in comparison to the amount of greenhouse gas forests store. Nevertheless, it may be high time to rethink people's perception of the actual value of carbon sinks.