By 2020 the UK will have very nearly halved its emissions over 30 years. Reducing emissions by the same amount over the next 30 years will get the UK very close to zero. However this will be very much more difficult.
A robust net zero target has been recommended for the UK …
A recent report by the UK’s Committee on Climate Change (CCC), the Government’s official advisory body, recommends that the UK adopts a legally binding target of net zero emissions of greenhouse gases by 2050[i], that is remaining emissions must be balanced by removal from the atmosphere. If the Government agrees, this will be implemented by amending the reduction mandated by the Climate Change Act, from an 80% reduction from 1990 to a 100% reduction.
The target has several features that make it particularly ambitious. It:
- sets a target of net zero emissions covering all greenhouse gases;
- includes international aviation and shipping;
- allows no use of international offsets; and
- is legally binding.
This is intended to end the UK’s contribution global warming. It has no precedents elsewhere, although in France a bill with comparable provisions is under consideration[ii].
Progress to date has been good …
The UK has made good progress so far in reducing emissions since 1990. Emissions in 2018 were around 45% below 1990 levels, having reduced at an average rate of about 12.5 million tonnes p.a. over the period. On current trends, over the thirty years from 1990 to 2020 emissions will be reduced to about 420 million tonnes p.a., 47% below their 1990 levels. Emissions will thus have nearly halved over the 30 years 1990 to 2020, half the period from 1990 to the target date of 2050.
Chart 1 shows how the UK’s progress compares with a linear track to the current target of an 80% reduction, to a 95% reduction and to a 100% reduction. (For simplicity I’m ignoring international aviation and shipping). The UK is currently on a linear track towards a 95% reduction by 2050.
Chart 1: Actual UK emissions compared with straight line progress towards different 2050 targets
Source: My analysis based on data from the Committee on Climate Change and UK Government. Data for 2018 is provisional[iii]
The largest contributor to the total reduction so far has been the power sector. Analysis by Carbon Brief[iv] showed that the fall in power sector emissions has been due to a combination deploying renewables, which made up about of third of generation in 2018, reducing coal use by switching to natural gas, and limiting electricity demand growth.
Industrial emissions have also fallen significantly. However some of this likely represents heavy industry now being concentrated elsewhere in the world, so likely does not represent a fall in global emissions. Emissions from waste have also fallen, due to better management.
Reducing emissions will be relatively easy in some sectors …
There are also reasons for optimism about continuing emissions reductions. Many technologies are now there at scale and at competitive prices, which they were not in previous decades. For example, falling renewables costs and better grid management, including cheaper storage, will help further decarbonisation of the power sector. Electrification of surface transport now appears not only feasible, but likely to be strongly driven (at least for cars and vans) by economic factors alone as the cost of batteries continues to fall.
But huge challenges remain …
Nevertheless important difficulties remain for complete decarbonisation.
CCS is identified by the report as an essential technology. However, as I have noted previously, it has made very little progress in recent years in the UK or elsewhere[v]. CCS is especially important for decarbonising industry. This includes a major role for low carbon hydrogen, which is assumed to be produced from natural gas using CCS – although another possibility is that it comes from electrolysis using very cheap renewables power, e.g. at times of surplus. CCS also looks to be necessary because of its use with bioenergy (BECCS), to give some negative emissions, though the lifecycle emissions from this will require careful attention
Decarbonising building heating, especially in the residential sector, continues to be a challenge. The report envisages a mix of heat pumps and hydrogen, perhaps in the form of hybrid designs, with heat pumps providing the baseload being topped-up up by burning of hydrogen in winter. I have previously written about the difficulties of widespread use of heat pumps[vi], and low carbon hydrogen from natural gas with CCS is also capital intensive to produce and therefore expensive to run for the winter only. The scale of any programme and consumer acceptance remain major challenges, and the difficulties encountered by the UK’s smart meter installation programme – by comparison a very simple change – are not an encouraging precedent.
Emissions from agriculture are difficult to eliminate completely, and no technologies are likely to be available by 2050 that enable aviation emissions to be completely eliminated. This will require some negative emissions to balance remaining emissions from these sectors.
Policy needs to be greatly strengthened …
Crucially several of the necessary transformations are very large scale, and need long lead times, and investment over decades. There is an urgent need to make progress on these, and policy needs to recognise this. This includes plans for significant absorption from reforestation, as trees need to be planted early enough that they can grow to be absorbing substantial amounts by 2050.
The UK’s progress on emissions reduction so far has been good, having made greater reductions than any other major economy[vii]. And technological advances in some areas are likely to enable substantial further progress. However much more is needed. In particular policy needs to look now at some of the difficult areas where substantial long-term investment will be needed
Adam Whitmore – 22nd May 2019
[ii] The CCC report notes that Norway, Sweden and Denmark have net zero targets, but they allow use of international offsets (up to 15% in the case of Sweden). France has published a target similar to the UK’s in a bill. The European Commission has proposed something similar for the EU as a whole, but this is a long way from being adopted. California has non-legally binding targets to achieve net zero by 2045. Two smaller jurisdictions (Costa Rica, Bhutan) have established net zero targets but these are expected to be achieved mainly by land use changes. New Zealand has a draft bill to establish a target, but eliminating all GHGs will be difficult because of the role of agriculture in the New Zealand economy.
[iii] https://www.gov.uk/government/statistics/provisional-uk-greenhouse-gas-emissions-national-statistics-2018 The change from 2017 to 2018 is applied to the data series from 1990 produced by the CCC (the two data series differ very slightly in their absolute levels).