The journal Nature recognises that technologies such as fracking have triggered a boom in natural gas. But the authors say this will not lead to a reduction of overall greenhouse gas emissions.
Although natural gas produces only half the CO2 emissions of coal for each unit of energy, its growing availability will make it cheaper, they say, so it will add to total energy supply and only partly replace coal. Their study, based on what they say is “an unprecedented international comparison of computer simulations”, shows that this market effect nullifies the advantage offered by the lower pollution content of the gas. This might eventually mean not lower CO2 emissions, but emissions by the middle of the century up to 10% higher than they would otherwise be. Not only could this lead to an overall increase in energy consumption and in emissions, but increased gas production would mean higher emissions of methane from drilling leakages and pipelines.
Haewon McJeon, staff scientist at the Joint Global Change Research Institute, a partnership between the US Department of Energy’s Pacific Northwest National Laboratory (PNNL) and the University of Maryland, said: “The upshot is that abundant natural gas alone will not rescue us from climate change.”
One of the co-authors, Nico Bauer, a sustainable solutions expert at the Potsdam Institute for Climate Impact Research (PIK), Germany, said : “The high hopes that natural gas will help reduce global warming because of technical superiority to coal turn out to be misguided because market effects are dominating. The main factor here is that an abundance of natural gas leads to a price drop and expansion of total primary energy supply.”
The research groups projected what the world might be like in 2050, both with and without a natural gas boom. They used five different computer models, which included not just energy use and production, but also the broader economy and the climate system.
“When we first saw little change in greenhouse gas emissions in our model, we thought we had made a mistake, because we were fully expecting to see a significant reduction in emissions,” said James Edmonds, chief scientist at the Joint Global Change Research Institute. “But when we saw all five teams reporting little difference in climate change, we knew we were on to something.”