The new US analysis suggests this may not be a sensible strategy, given that the total carbon footprint appears bigger - especially if the gas comes from shale formations.

Greenhouse gas emissions from shale gas are predominantly down to two things: carbon dioxide produced when the gas is burned, and methane that leaks out while the well is being exploited.

But Dr Kharaka nevertheless suggests that the sequestration of carbon dioxide should be confined to deep aquifers, where overlying layers of shale would be likely to prevent leaks.