The American shale gas revolution shaved more off global carbon emissions than all the world’s windfarms and solar panels put together in 2012 according to Chris Faulkner, boss of US fracking firm Breitling Energy.
We think he’s wrong. Even with some pretty heroic assumptions, he’s only almost right. Let’s see why.
The UK connection
Faulkner made his claim at a fringe meeting of the Council of Europe in Strasbourg. He had been invited to speak by UK Conservative MP David Davis, a long-standing critic of climate change policies in general and wind energy in particular.
“In 2012, the shift to gas has managed to reduce carbon dioxide emissions by about 300 million tonnes. Compare this to the fact that all the wind turbines and solar panels in the world reduce carbon dioxide emissions, at a maximum, by 275 million tonnes. In other words, the US shale gas revolution has by itself reduced global emissions more than all the well-intentioned solar and wind in the world.”
US coal emissions
To start with, let’s look at US coal emissions. In 2012, US coal plants emitted 1,653 million tonnes of carbon dioxide. That’s 529 million tonnes below peak coal emissions, which were 2,182 million tonnes in 2005.
Let’s generously assume all of that reduction is due to cheap shale gas displacing coal use. It takes about half as much carbon to generate a unit of electricity from gas as it does from coal. So the maximum carbon saving is half the coal emissions avoided. That’s 265 million tonnes of carbon dioxide, in the same ballpark as the 300 million tonnes Faulkner claimed.
In reality, some of the reduction in coal use will have been because overall electricity demand in the US has fallen since 2005 while solar and wind power output has also grown. So assuming all of the fall in coal use was caused by the shale gas revolution is probably not a good idea. But let’s stick with that 265 million tonne figure for now.
Global wind and solar electricity
Next let’s look at how much electricity was produced in 2012 from solar and wind. One report puts this at 534 terawatt hours for wind and 105 terawatt hours for solar. That’s 639 terawatt hours in total.
Factoring in the energy needed to build the wind turbines and manufacture the solar panels, emissions per unit of electricity are about 99 per cent lower for wind than for gas. For solar panels it’s about 90 per cent lower.
Let’s be as pessimistic as possible, and assume that all the wind and solar power we’ve built has displaced relatively clean-burning gas. In that case wind and solar power would have saved 312 million tonnes of carbon dioxide in 2012 – again, close to the 275 million tonnes quoted by Faulkner.
So, according to our back of the envelope calculation, the 312 million tonne saving from wind and solar is bigger than a 265 million tonnes saving from US shale gas.
And remember, we’re being as generous as possible to shale gas here. There are other things cutting US coal use – like the economic downturn – and some of the renewable power that has been built will have displaced higher-polluting coal, meaning bigger emissions savings.
It’s also worth pointing out that some of the coal that hasn’t been burnt in the US has been burnt in Europe instead – so on a global scale, the emissions savings will be smaller still.
Wind and solar have been growing fast. Historical data shows global electricity production from these two sources has increased by 29 per cent each year. On that trajectory, wind and solar plants would top 1,000 terawatt hours output this year.
That would avoid the emission of 1 billion tonnes of carbon dioxide if they displaced coal, and half a billion tonnes if displacing gas. Global emissions are around 34 billion tonnes per year so these are worthwhile savings, but you can also see the enormous scale of the carbon emissions problem.
President Obama’s power sector plan aims for a 30 per cent emissions saving across the US power sector against a 2005 baseline, by 2030. That would be 691 million tonnes. As we wrote at the time, nearly half (286 million tonnes) of that reduction has been achieved already between 2005 and 2013.
It’s fair to say that shale gas has had a dramatic impact on US emissions, but we don’t think Faulkner is right to say the achievement tops the effect of wind and solar plants around the world.