A debate has raged for years as to whether natural gas is better or worse overall than coal and oil from a global warming perspective. The back-and-forth findings have been due to length of the studied time, the details of natural gas extraction, and the electricity-generating efficiency of various fuels. A new study from Cornell addresses this question by comparing the reduction of greenhouse warming that would result from substituting gas for coal and some oil to the reduction which could be achieved by instead substituting zero carbon energy sources. It was shown that substitution of natural gas reduces global warming by 40% of that which could be attained by the substitution of zero carbon energy sources. the study does not consider secondary considerations, such as economic, political, or other environmental concerns and focuses instead on global warming only.
To come to this conclusion, the author (Cathles of Cornell)considered three different future fuel consumption scenarios:
(1) a business-as-usual case, which sees energy generation capacity continue at its current pace with its current energy mix until the middle of the century, at which point the implementation of low-carbon energy sources dominates and fossil fuel-derived energy production declines;
(2) a gas substitution scenario, where natural gas replaces all coal power production and any new oil-powered facilities, with the same midcentury shift;
(3) a low-carbon scenario, where all electricity generation is immediately and aggressively switched to non-fossil fuel sources such as solar, wind, and nuclear.
No matter the time frame considered, he concluded, substituting natural gas energy for all coal production and some oil production provides about 40 percent of the global warming benefit that a complete switch to low-carbon sources would deliver, making this a good intermediary step.
Other researchers (for example, leading climate scientist Ken Caldeira and former Microsoft executive Nathan Myhrvold) have found that the climate change related benefits of natural gas are not great enough to warrant its use as a bridge fuel (that we should just be going straight into renewable energy. This is still a contentious point of debate within this field.
"From a greenhouse point of view, it would be better to replace coal electrical facilities with nuclear plants, wind farms and solar panels, but replacing them with natural gas stations will be faster, cheaper and achieve 40 percent of the low-carbon-fast benefit," Cathles writes in the study. "Gas is a natural transition fuel that could represent the biggest stabilization wedge available to us."
For further information see Gas Study.
Extraction image via Wikipedia.