Professor Robert Howarth:

Much has changed since 2006 and the committee heard a nice explanation of that. The consequences of climate change are coming into much sharper focus. We are seeing more consequences of stronger storms, more fires, larger droughts and bigger floods.

Also, there was the COP 21 agreement in Paris in 2005 when the nations of the world finally agreed that we need to try to keep the increase in temperature on the planet well below 1.5°C because of the possibility of climate thresholds and tipping points, and certainly well below 2°C. That is a new understanding by nations. We are on a trajectory to break through that 1.5°C ceiling in the timeframe of 15 to 20 years from now, in part driven by methane emissions from oil and gas development.

Regarding the shale gas side of it, as of 2006 there has been virtually no shale gas development anywhere in the world. Half of the shale gas that has ever been produced has been produced in the past five or six years and our scientific understanding has also changed markedly over time. In 2011, we published the first ever analysis of what methane emissions from shale gas might look like. The analysis had to be a little speculative because there were few data on what was then a brand new technology. There are now hundreds of papers on this area and we know those methane emissions are substantial. The science is now dramatically different from when this project was first considered.