Recent advances in gas production technology such as hydraulic fracturing – also known as fracking – and horizontal drilling have led to bountiful natural gas, though so far mostly in the US. The substitution of coal with gas, which emits less CO2, is one of the reasons for the recent decline in US emissions. Climate change, however, is determined by the amount of global emissions –past and future. Assuming that such a gas boom could continue and possibly expand to other countries, the question of interest became: could these advanced technologies also have an impact on global emissions?

To find out, a team of scientists, engineers and policy experts, led by PNNL’s Joint Global Change Research Institute, gathered at a workshop in Cambridge, Maryland, in May 2013 to consider the long-term impact of the current natural gas boom on the rest of the world. Five groups, hailing from the US, Australia, Austria, Germany and Italy, went home and projected what the world will be like in 2050 with and without a natural gas boom.

Massimo Tavon, researcher at the Centro Mediterraneo sui Cambiamenti Climatici and professor at the Politecnico di Milano, and Giacomo Marangoni (CMCC and Polimi) are among the authors.

Abstract
The most important energy development of the past decade has been the wide deployment of hydraulic fracturing technologies that enable the production of previously uneconomic shale gas resources in North America. If these advanced gas production technologies were to be deployed globally, the energy market could see a large influx of economically competitive unconventional gas resources. The climate implications of such abundant natural gas have been hotly debated. Some researchers have observed that abundant natural gas substituting for coal could reduce carbon dioxide (CO₂) emissions. Others have reported that the non-CO₂ greenhouse gas emissions associated with shale gas production make its lifecycle emissions higher than those of coal. Assessment of the full impact of abundant gas on climate change requires an integrated approach to the global energy–economy–climate systems, but the literature has been limited in either its geographic scope or its coverage of greenhouse gases. Here we show that market-driven increases in global supplies of unconventional natural gas do not discernibly reduce the trajectory of greenhouse gas emissions or climate forcing. Our results, based on simulations from five state-of-the-art integrated assessment models of energy–economy–climate systems independently forced by an abundant gas scenario, project large additional natural gas consumption of up to +170 per cent by 2050. The impact on CO₂ emissions, however, is found to be much smaller (from −2 per cent to +11 per cent), and a majority of the models reported a small increase in climate forcing (from −0.3 per cent to +7 per cent) associated with the increased use of abundant gas. Our results show that although market penetration of globally abundant gas may substantially change the future energy system, it is not necessarily an effective substitute for climate change mitigation policy.

McJeon  H., Edmonds J. , Bauer N., Clarke L. E. , Fisher  B., Flannery B. P. , Hilaire  J., Krey V., Marangoni G., Mi R., Riahi K., Rogner H., Tavoni M. Limited impact on decadal-scale climate change from increased use of natural gas, 2014, Nature, DOI: 10.1038/nature13837, web page