Instead of being an answer to climate change, shale gas might actually be a major generator of greenhouse emissions.
According to a new study done by three Cornell University researchers, the problem with shale gas is the amount of methane it releases into the atmosphere.
But there is still debate over the impact of a ton of methane compared to a ton of carbon dioxide. Methane has a half-life of 10 years, while carbon dioxide has a half-life of decades. So shale gas supporters say any methane released in the atmosphere will disappear faster than carbon dioxide.
However, Cornell University Ecology Professor Robert Howarth, one of the authors of this study, believes the short term future is most important.
"We run the risk of warming the planet up to 1.5 to 2 degrees above the long term average temperature. We'll hit that critical threshold somewhere in the period of 15 to 35 years from now unless we get methane under control," Howarth said. "Methane is an extremely potent greenhouse gas."
Another issue with shale gas is the combined amount of methane and carbon dioxide it produces.
"The greenhouse gas footprint of shale gas also exceeds that of oil or coal when considered at decadal time scales, no matter how the gas is used," Howarth said.
The rise in shale gas's popularity is due in part to two factors. According to the authors, most of the United States' conventional natural gas will be used up within the next 30 years, so shale gas provides the country a valuable and viable way to prolong that depletion. The second is that shale gas is seen as a "bridge fuel" or transitional fuel between conventional gas and alternative energies such as solar, hydrogen, and wind. Even though alternative energy sources have drastically improved over the past two decades, they are not at the level where they can provide the energy required for the whole country.
However, Cornell University Environmental Engineering Professor Anthony Ingraffea, another author for this study, believes instead of spending money on developing shale gas, investors should place their money elsewhere.
"Would that capital be better spent on constructing a smart electric grid, and truly sustainable green and electric technologies?" Prof. Ingraffea said. "We conclude again that framing shale gas development as a bridge fuel makes no sense."
Ingraffea continued, "It's simply a bridge too far."