Environmental Tipping Point Near? Scientists Call for Methane Controls

As the shale gas boom continues, methane continues to seep into the atmosphere and exacerbates Earth's greenhouse gas problem. Now, scientists believe that we may not be many years away from an environmental tipping point that could result in runaway warming.

Natural gas is a major source of atmospheric methane due to widespread leaks and even purposeful venting of gas. Methane gas actually contributes over 40 percent of current radiative forcing, which is a measure of trapped heat in Earth's atmosphere from man-made greenhouse gases.

"We have to control methane immediately, and natural gas is the largest methane pollution source in the United States," said Robert Howarth, greenhouse gas expert, in a news release. "If we hit a climate-system tipping point because of methane, our carbon dioxide problem is immaterial. We have to get a handle on methane, or increasingly risk global catastrophe."

There is some light at the end of the tunnel. The climate system actually responds much more quickly to reducing methane than carbon dioxide emissions. This means that controlling methane emissions could drastically decrease warming. By that same token, though, if society aggressively controlled carbon emissions but ignored methane emissions, the planet would still warm to the dangerous 1.5- to 2.0-degree Celsius threshold within 15 to 35 years.

Society needs to wean itself from the addiction to fossil fuels as quickly as possible," said Howarth in a news release. "But to replace some fossil fuels-coal, oil-with another, like natural gas, will not suffice as an approach to take on global warming. Rather, we should embrace the technologies of the 21^st century and convert our energy systems to ones that rely on wind, solar and water power."

The findings reveal how important it is to control gas emissions, especially as our climate continues to warm. If an environmental tipping point is reached, it will be difficult to curtail the effects.

The findings are published in the journal Energy Science and Engineering.