This is an ambitious target and, unsurprisingly, comes at a cost, estimated at 0.5-2% of GDP by 2050.
By reducing greenhouse gas emissions to zero the UK would "end our contribution to the rising global temperatures".
Meeting this objective would require a wide range of measures. These include "firm plans for housing and domestic heat, for industrial emissions, carbon capture and storage, road transport, agriculture, aviation and shipping".
Some of these measures will incur extra costs or require additional electricity generation, or both.
The CCC envisages a substantial contribution from offshore wind, which, together with inputs from onshore wind and solar photovoltaics, would result in savings that would offset the additional costs associated with some of the measures to cut emissions.
Electricity consumers in the UK currently pay around £7 billion (€7.8 billion) a year to support low-carbon technologies.
That figure will rise to around £12 billion (€13.4 billion) by 2030 and then fall, as current contracts expire and new contracts at significantly lower costs increasingly take over.
The committee anticipates a reduction in new power-sector costs of £7 billion per year between 2030 and 2050.
The CCC's estimates of the way the generating costs of the principal technologies will evolve are shown in the chart (below).
These include an allowance of £20/MWh (€22.4/MWh) for the carbon price attached to gas generation, although it is noted that the renewable technologies are becoming increasingly competitive even before this is taken into account.
By 2050 costs for renewables are expected to lie in the £40-£50/MWh range, compared with £39-£66/MWh for gas (excluding carbon price) and £70-£80/MWh for nuclear and CCS.
The committee is ambivalent about the prospects for nuclear. In the introduction to the accompanying technical report, it suggests, "renewables and possibly nuclear power" will be required to reduce emissions close to zero. Elsewhere, however, it notes that "technologies that have not been deployed at scale... have failed to come down in cost".
The cost estimates shown in the chart above suggest that nuclear will struggle to become competitive with renewables, with significantly higher generating costs in 2050 than those of renewables.
This is reflected in a modest contribution from nuclear in the "illustrative generation mix in 2050", shown in the chart on the right, which puts the total contribution from nuclear (existing and new) at 69TWh; while "variable renewables (largely offshore wind)" contribute 369TWh.
The reports do not specify the precise components of the 2050 generation mix, but suggest that 75GW of offshore wind could be deployed without difficulty. Current offshore capacity is 8GW, and the government is committed to deploying 30GW by 2030, the CCC notes.
The results of a new auction for contracts the difference for offshore wind will be announced very shortly, and it is expected that the successful bidders will offer prices close to or below the current level of wholesale electricity prices.
Apart from solar PV, no other technologies emerge as serious competition for wind. The committee’s main report does not mention wave or tidal power, although these are referred to as "speculative options" in the technical report. The CCC is hopeful that the costs of carbon capture and storage will come down. Several possibilities are under investigation, but future prices are still somewhat uncertain.
The report has generally been welcomed by interested parties, although it has been noted that the UK currently looks likely to undershoot its current target of becoming 80% carbon-free by 2050.
As the shape of the electricity system will be radically altered due to the need for additional electrification in the transport sector, for hydrogen production and for heating, the role of wind becomes more important. The committee suggests that by 2050 electricity consumption will double from its present level to around 650TWh, of which wind would contribute around half.
At a glance — This month’s report conclusions
Net Zero – The UK’s contribution to stopping global warming, Committee on Climate Change, 2 May 2019 Concludes the foundations are in place for the UK to work towards net-zero greenhouse gas emissions by 2050, but policies will have to ramp up significantly. The committee judges the overall costs of the transition as manageable.
Net Zero – Technical Report, Committee on Climate Change, 2 May 2019 Provides supporting charts and data to the Net Zero advice report