Because increased temperature also affects greenhouse gas emissions that arise naturally, global warming will progress faster than what was previously believed, projects a new study.
The findings suggest a vicious circle - greenhouse gas emissions from the burning of fossil fuels lead to higher temperatures, which in turn lead to increased natural emissions and further warming.
This means that warming will be faster than expected from anthropogenic greenhouse gas emissions alone, the researchers noted.
"We are not talking about hypotheses anymore. The evidence is growing and the results of the detailed studies are surprisingly clear. The question is no longer if the natural emissions will increase but rather how much they will increase with warming," said one of the researchers David Bastviken, professor at Linkoping University in Sweden.
The researchers examined the emissions of the greenhouse gas methane from three lakes.
The effects were clear and the methane emissions increased exponentially with temperature.
Their measurements showed that a temperature increase from 15 to 20 degrees Celsius almost doubled the methane level.
"Everything indicates that global warming caused by humans leads to increased natural greenhouse gas emissions. Our detailed measurements reveal a clear pattern of greater methane emissions from lakes at higher temperatures," study lead author Sivakiruthika Natchimuthu from Linkoping University pointed out.
The findings were published in the journal Limnology and Oceanography.
