Gas plays an essential role in the UK’s energy mix, providing heat for homes and electricity to sockets. While that’s not likely to change in the short term, the fuel will need to be increasingly phased out as the government seeks todecarbonise the energy sector.

A trawl through new governmentdatashows how far the UK’s come in recent years, and hints at challenges to come.

Gas trends

The UK currently uses three trillion cubic feet of gas each year. That demand may need to fall by as much as20 per centover the next two decades if the UK is going to hit itsclimate targets.

The Department of Energy and Climate Change’sDigest of UK Energy Statistics, releasedlast week, shows how much would need to change for that to happen.

DECC’s data shows gas demand has fallen 17 per cent in the last five years. But while demand has fallen significantly from 2011’s high, its plateaued in recent years. Demand was only one per cent lower in 2013 compared to a year before.

Gas is mainly used for two things, as the blue and purple sections of the graph below show: generating electricity, and heating people’s homes.

DECC’s data shows gas is being used increasingly sparingly to generate electricity. The amount of gas used in electricity generation fell by 13 per cent last year. But that doesn’t necessarily spell good news for the UK’s emissions.

As the graph below shows, while gas generation is dropping, coal power is being ramped up. And Coal power has almost twice the emissions of gas.

That’s why some people, including prime minister David Cameron, are keen to promote gas as atransition fuelwhile the UK seeks to wean itself off coal power and onto renewable electricity. But the UK’s official advisor, the Committee on Climate Change (CCC), haswarned againstan all-out “dash for gas”.

In 2012, the government released a strategy outlining three scenarios for the future of gas power. The strategy suggestsbetween 26 and 37 gigawatts of new gas capacitycould be built by 2030. The former would mean the government hits its legally binding emissions reduction goals, the CCC says. The latter means the target would probably bemissed, it warns.

Curbing households’ demand for gas heating is an altogether trickier business, as it largely relies on the weather. DECC’s data shows that people reaching for the thermostat during particularly cold years can lead to around 50 terrawatt hours of additional gas demand. The government hopes its energy efficiency scheme – theGreen Deal——将有助于抑制这种飙升,尽管计划has had atroubled start.

Cleaner imports

Where the UK’s gets its gas also has an impact on emissions.

The UK imports most of its gas, as domestic production continues to decline. Gas is imported in two ways: through pipelines connected to Ireland and Europe, and as Liquefied Natural Gas (LNG).

Government researchshows the production and transportation of LNG can emit significantly more than gas piped from the continent.

The good news is that the UK is importing a lot less LNG than it once was, as the purple chunk on the graph below shows. At its height, the UK LNG accounted for 47 per cent of the UK’s gas imports (in 2011). In 2013, that was down to 20 per cent.

That’s partly because pipelines connected to Norway and Belgium were back up and running aftermaintenance works– hence the upward trajectory of the pink and purple lines on the graph below. It’s also because demand for LNG has spiked in Asia, and particularly in Japan after it shut down its nuclear power stations, driving the LNG price up.

As a consequence, the UK’s main LNG supplier, Qatar, is sending increasing amounts of LNG south east rather than to the UK, which isn’t willing to match Asia’s price. In 2013,62 per centof Qatar’s LNG was exported to Asia, with only 30 per cent going to Europe.

If the UK is going to use gas as a bridging fuel while curbing its emissions, it will need to continue to import as much as possible from the continent rather than alternative sources.Shale gascould potentially play a role, but only iffugitive methane emissions就会受到限制。寻找替代低排放gas sources will get ever more pressing asNorth Sea wells dry upand Norway’s resources becomeincreasingly depleted.

Reducing dependency

In itsbig climate reportreleased earlier this year, the Intergovernmental Panel on Climate Change said natural gas could play a role in the decarbonisation effort – but onlyin a controlled way. Gas could be a substitute for higher-emitting coal, as long as emissions from the energy sector shrink rapidly throughout this century, it suggests.

The UK government already has a number of policies it hopes will help wean the UK off gas.

Households can install a range ofenergy efficiency measuresunder the Green Deal scheme – such as more efficient boilers and insulation – which should help cut domestic gas demand. Though improvements have slowed compared to thescheme’s predecessor.

The government is also committed to ramping up renewable electricity generation which, combined withenergy storageandinterconnectorsto the continent, should reduce the number of hours fossil fuel plants need to operate.

If the UK is going to hit its climate targets, such policies will need to ensure gas demand decreases in the long run without more-polluting energy sources filling the gap.