Natural gas finally fulfilled its environmental promise this century. Long touted by environmentalists for being much cleaner than coal, hydraulic fracturing - fracking - made it economically viable as well.

The resulting boom also offset the lingering economic malaise in America for states, like Pennsylvania, that embraced it. Poor people could still afford energy but CO2 emissions went back to early 1990s levels, while coal, which had skyrocketed in use when nuclear energy was banned in America, was suddenly back at 1980s levels.

But the rest of the world has not embraced it yet. Europe, like New York state, is happy to import natural gas from neighbors but they are concerned about the voter reaction if they do it themselves. There is still plenty of coal and countries are using that because it remains cheap.

A new computer simulation claims a natural gas boom worldwide would not solve the global warming crisis anyway. The reason is because cheap natural gas makes nuclear less viable - we have seen that in the American environmental movement, where they used to claim nuclear science was dangerous and now say it is too expensive. Solar and wind are already just limping along on government subsidies and while wind will never be a real alternative, solar will be, given enough time to develop better technology than exists now.   

"The upshot is that abundant natural gas alone will not rescue us from climate change," says lead author Haewon McJeon of the Department of Energy's Pacific Northwest National Laboratory (PNNL). 

Estimate finds emissions might instead rise by 10 percent

Instead, more natural gas might eventually lead to up to 10 percent higher CO2 emissions by the middle of our century, they estimate.

"The additional gas supply boosts its deployment, but the substitution of coal is rather limited and it might also substitute low-emission renewables and nuclear, according to our calculations," says co-author Nico Bauer of the Potsdam Institute for Climate Impact Research. "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."

This could lead to an overall increase of energy consumption and hence of emissions. Moreover, increased gas production comes with higher emissions of the powerful greenhouse gas methane from drilling leakages and pipelines.

The uncertainty surrounding gas supply is tremendous – the assessment of global natural gas resources have been revised over the past decade, but the economic implications up to now were not well understood.

The pessimism: Technological advances won't happen, climate laws are needed

So five research groups from Germany, USA, Austria, Italy and Australia projected what the world might be like in 2050 with and without a natural gas boom. They used five different computer models that 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 scientist James 'Jae' Edmonds of PNNL's Joint Global Change Research Institute. "But when we saw all five modeling teams reporting little difference in climate change, we knew we were onto something."

"The findings show that effective climate stabilization can be achieved only through emissions pricing – this requires international political cooperation and binding agreements," comments Ottmar Edenhofer, chief economist of PIK and co-chair of the working group on mitigation of the Intergovernmental Panel on Climate Change (IPCC) that recently published a milestone assessment report. "Technological advances can reduce the costs of climate policies – but they cannot replace policies."