As everybody knows, the easiest target for decarbonisation has been the electricity generation sector. But that leaves some seriously intractable problems - energy-intensive industry, transport, food/agriculture/land-use, and space heating - which in aggregate are significantly bigger consumers of fossil fuels, and also (with the exception of some industries) much less centralised, i.e. interventionist measures are much more difficult. Only the supply-side of transportation (oil companies now, electric utilities in the distant future) is *easily* dealt with, in the sense of nobbling a handful of large players that governments know how to transact with.
One of the difficult areas - some would say the most difficult - is space heating in residential properties, in a country like the UK where gas is by far the predominant fuel. Electrification? Consider this: peak winter energy demand for space heating that is currently fuelled by gas, is a multiple of peak electricity demand for all purposes. So: although the grid starts with a bit of headroom arising from overall energy consumption having been falling slowly for many years now, basically the grid and the generating fleet would need to be more than doubled in capacity, in almost every facet, in order simply to electrify home heating. That leaves electrification of transport still to be catered for. (With a bit of management, that might just sneak in with the grid upsizing required for heating, if all the vehicles could be charged in the small hours.)
Politicians having been banging on about legislating towards decarbonising homes for several years now. One of Sadiq "Showman" Khan's more fatuous actions was to "regulate" that all London newbuild houses would be zero carbon from, errr, 2019. But then, seeing there wouldn't be any new housebuilding, he changed his mind.
HMG is at it now:
Heat pumps will become the principal low-carbon heating technology in new homes, the government has said. The Ministry for Housing, Communities and Local Government has responded to feedback to a consultation it conducted just over a year ago into its proposals for a Future Homes Standard that will govern new residential development from 2025. The response confirms the government’s commitment in the Treasury’s 2019 Spring Spending Statement to ban the installation of fossil fuel heating, such as natural gas boilers, in new-build homes by the middle of this decade. (UtilityWeek)
Grammarians, pedants and skeptics amongst you will have identified the weasels there: principal technology might mean "majority of installations" (51%?) or even "biggest single technology" (alongside gas and old-style electric and district heating etc etc).
Note also that heat pumps are only "low" carbon - because of course they use electricity from the mains! Given that homes presumably includes urban flats, we must also assume it's to be air-source pumps as well as ground-source - a very questionable proposition. And then there's the finance. The RHI was meant to incentivise ground-source heat pumps as much as biomass, but in this it failed dismally. We're talking serious cost here: and that's before anyone even mentioned retrofit.
If they really mean it, new house building will slow to a crawl (just as 2,000,000 Hong Kongers turn up ...). Still, "ban" is ban. Ask Sadiq, eh?