Natural Gas a Weak Weapon Against Climate Change, New Study Asserts
Although natural gas burns more cleanly than coal, a new study argues that replacing all the world’s coal power plants with natural gas would do little to slow global warming this century.
“There are lots of reasons to like natural gas, but climate change isn’t one of them,” said physicist Nathan Myhrvold, lead author of the new study. “It’s worthless for [fighting] climate change, as far as we can tell.”
The reason for that grim assessment: The carbon dioxide burden already is so large, and its lifetime in the atmosphere is so long, that even a switch to completely carbon-free electricity couldn’t stop temperatures from rising over the next 100 years. Switching from coal to natural gas would cut the warming effect in 100 years’ time by only about 20 percent, while switching to renewable or nuclear energy would slash the warming effect about two-thirds to three-quarters.
With this new study, Myhrvold has set out in a new direction. The former chief technology officer of Microsoft and founder of Microsoft Research, Myhrvold has also studied cosmology with Steven Hawking and published scientific studies on dinosaurs—including one on fossilized vomit. These days Myhrvold runs a company called Intellectual Ventures, and recently co-authored Modernist Cuisine, a six-volume tome on the science of cooking.
Myhrvold has long been interested in climate change, and for the new study he teamed up with climate researcher Ken Caldeira of the Carnegie Institution for Science in Stanford, California, to compare a variety of alternatives to coal-fired power plants.
The two scientists were wondering what effect it would have on the climate if the world were to switch from coal to any of a menu of other options. “We realized nobody had done it”—at least not in a systematic way, Myhrvold said. “I decided to take it to the lunatic extreme and try to do it myself.”
Turning the Switch
The world currently has enough coal-fired power plants to produce about one terawatt of electricity—the equivalent to each of the seven billion people on Earth using two 75-watt light bulbs at the same time.
In their study published in February in Environmental Research Letters, Myhrvold and Caldeira looked at switching from one terawatt of coal power plants to natural gas-or to solar panels, or wind, or nuclear, or other options. And they tested the effects of making the whole transition in one year—a pace Myhrvold called “insane”—or over as long as a “leisurely” 100-year span.
“We found some really counterintuitive results,” Myhrvold said.
Compared to emissions from coal, “cutting emissions by a factor of two or three hardly makes a difference,” he said. To avoid a significant amount of warming this century, he added, “you must cut emissions by a dramatic factor”—by ten or twenty times.