Burning natural gas may emit significantly less carbon dioxide than coal, but a fifty percent switch from coal to natural gas would not stem the tide of climate change, according to the results of a new study
Using computer simulations, Tom Wigley, a senior research associate at the National Center for Atmospheric Research, found that a "partial shift from coal to natural gas would slightly accelerate climate change" for at least the next several decades, reports Science Daily. After that, there would be only a minimal slow down in the rise of global average temperatures. The report, "Coal to gas: The influence of methane leakage," appears in the journal Climatic Change Letters.
Wigley's predictions are dependent upon the amount of methane, a potent greenhouse gas, that is leaked as a result of natural gas production. If there was no leakage after a shift to gas, climate change would be accelerated through 2050. But if there were significant leaks, it could be as late as 2140 before any difference was seen, according to the Los Angeles Times.
Wigley explains that natural gas does produce less heat-trapping carbon dioxide when burned than coal. But coal emits other particles that also block sunlight and cool the planet. He tells Science Daily:
"Whatever the methane leakage rate, you can't get away from the additional warming that will occur initially because, by not burning coal, you're not having the cooling effect of sulfates and other particles. This particle effect is a double-edged sword because reducing them is a good thing in terms of lessening air pollution and acid rain. But the paradox is when we clean up these particles, it slows down efforts to reduce global warming."
Limiting methane leakage from natural gas production could also be a daunting task. The New York Times covered a report in April that suggested as much as 7.9 percent of the methane that is currently escaping into the atmosphere is "puffing out from shale gas wells, intentionally vented or flared, or seeping from loose pipe fittings along gas distribution lines."
Even after the warming caused by the reduction of sulfates and other earth-cooling particles is overcome, the decrease in rising global temperatures would not be significant.
Science Daily reports that even at only two percent methane leakage, a fifty percent shift to natural gas would only slow rising temperatures by 0.2 degrees Fahrenheit by 2100. With current energy trends, global temperatures are predicted to rise 5.4 degrees Fahrenheit by the end of the century.
The U.S. Geological Survey reported in August that the Marcellus Shale region has around 84 trillion cubic feet of recoverable natural gas. This is far less than the 410 trillion cubic feet statistic released earlier this year by the federal Energy Information Administration.
Click here for ProPublica's list of America's 10 largest gas drillers.