Bear with me here. We’d all rather discuss the fifth moon discovered orbiting Pluto, or the plan to introduce genetically modified mosquitoes into Florida. Maybe even the brown algae that’s threatening the ecosystems of China’s lakes is more compelling. But at some point soon, we really have to pay attention to fracking.

In mid-July, at Preston Magistrates’ Court, three people were convicted of aggravated trespass and assault. The trio had occupied a rig that was test-drilling to see whether shale gas could be released from the rocks two kilometres beneath Hesketh Bank in Lancashire. The defence argued that their actions were justifiable in terms of the greater good. Sometimes, they argued, you have to break the law in order to prevent others from committing greater wrongs. The shale gas is to be liberated by a process called hydraulic fracturing, better known as fracking. The protesters say this will pose a grave threat to the planet because burning this gas releases vast quantities of carbon dioxide.

Cuadrilla, which owns the oil rig, has not broken any laws. Nonetheless, there is some discomfort about its plan to pump water into the ground to break up rocks that are holding shale gas reserves. The anti-fracking protesters say they want the British public to start discussing these reservations, rather than pretending that there are more important things to talk about.

So, let’s talk. The first concern is that fracking increases the chance of seismic activity. That is true, according to the Geological Society. But, it adds, there’s not really anything to worry about. Fracking won’t cause big earthquakes in the UK because our portion of the earth’s crust can’t store a lot of energy before it slips and releases it all in an understated, very British quake.

Next up is the contamination of groundwater by methane released in the process. In the US, this does seem to have happened. But, the Geological Society said, it doesn’t have to: there is no evidence that, properly done, and properly regulated, fracking will make local water undrinkable.

The third problem is water use. Fracking involves pumping water into the ground and then bringing it back up (and cleaning it). The amounts involved are about only 0.01 per cent of licensed annual water extraction for England and Wales. The cleaning is possible. So far, so good.

The fourth problem is that the point of all this – burning shale gas as part of the nation’s energy mix – will lost us a lot of carbon emissions. According to researchers at the Tyndall Centre in Manchester, if we burn one fifth of the reserves identified under Lancashire, the resulting CO2 emissions would account for 15 per cent of the government’s greenhouse-gas emissions budget through to 2050. You can add to that the contention that allowing 3 per cent of the shale gas to leak away (not implausible, if regulation is not watertight) would make shale-gas use equivalent, in terms of its carbon impact, to the environmental catastrophe of burning coal.

Emission impossible

So, there are two decisions to make. First, do we trust the regulators to do a good job in minimising the environmental impact of fracking? Second, do we want to be part of the generation that decided not even to bother trying to meet reductions in carbon emissions?

The protesters had no expectation that they would stop Cuadrilla. They just hoped their action might attract our attention. The company expects government permission to extract shale gas from UK soil any day now: it is looking at an August or September kick-off for its operations. Is that OK with you? Don’t say no one asked.

Michael Brooks’s “The Secret Anarchy of Science” is published by Profile Books (£8.99)