Jackdaw: Will it cut energy bills and how much gas will it provide?

The enviromental impact of Jackdaw has also been a significant point of contention. Advocates argue the gas field would be beneficial because the carbon emissions arising from production from the the UK’s own North Sea field will be lower than those arising from the production of US LNG.

The North Sea Transition Authority (NSTA), which regulates the sector, has estimated the emissions arising from the production, delivery and processing of US LNG are around three times higher than from the production of North Sea natural gas.

That is because the process of liquefying, shipping and then turning LNG back in to natural gas on arrival is extremely energy intensive, compared with pumping it ashore by a pipeline, creating higher carbon emissions.

However, NSTA estimates that Norwegian North Sea gas production – which Britain already imports by pipeline in large volumes – has a considerably lower average emissions impact than that of the UK’s existing North Sea gas production.

This is because UK North Sea gas mostly comes from smaller fields and is extracted with older infrastructure and technology than those of Norway.

The owner of Jackdaw estimates the emissions intensity, external of its production would be lower than from older UK North Sea infrastructure – though it would still be higher than gas produced from Norwegian fields.

So the impact on the environment of the Jackdaw decision partly depends on what happens to the mix of UK gas consumption in future – and where it comes from – which is uncertain.

If additional gas production from Jackdaw displaces US LNG imports, UK-related national emissions could be lower than otherwise.

But if additional gas production from Jackdaw displaces gas imports from Norway instead then UK-related national emissions could be higher than otherwise.