Getting to net-zero emissions in the UK

Last week the Climate Change Committee (CCC) in the UK released its much anticipated report which is recommending that the government revise its emissions goal to net-zero in 2050. The Committee notes that this is an appropriate UK contribution towards the global need of meeting the goals of the Paris Agreement. The recommendation also follows in the wake of the IPCC Special Report on 1.5°C, which identified 2050 as the year in which the global economy should attempt to reach net-zero emissions in order to limit warming to 1.5°C with a 66% probability.

The recommendation is a shift from the current UK target which would see the country reach an 80% reduction by 2050, in support of which the country is broadly on track to deliver the first 3 interim carbon budgets to 2022. However, as it looks past 2022 the CCC notes there is insufficient early development of some technologies for the heavy lifting ahead. Examples of this include carbon capture and storage (CCS) and hydrogen for a variety of uses.

Nevertheless, the state of technology development, deployment and availability has shifted since the time of the first UK target back in 2008. The cost of wind and solar has dropped significantly, offshore wind is now a viable proposition, many electric car models are available and while not in the UK, some 20 CCS facilities are now running in various parts of the world. All of the technologies required to do the job set out by the CCC are in plain sight, although a number still require significant UK development for deployment in this country. The CCC report is also very clear on this issue.

2050 is just over thirty years away and that same time period reflecting backwards marks the time that I first arrived in the UK with Shell. In the next 30 years the whole energy system will need to shift to achieve net-zero emissions, but how does that compare with the changes seen over the last 30 years. While two thirds of that period has not been covered by the Climate Change Act and its carbon budgets, all but three years have been covered by the UK ratification of the UN Framework Convention on Climate Change.

The Sankey diagrams below reflect the change over the period, although the most recent from the IEA are 2016, so they won’t show the last two years of renewable energy development.

Overall primary energy consumption has fallen, with the most visible change being the shift away from coal and towards natural gas in power generation. Both bioenergy and renewables have also added to the generation mix. Nuclear plays an important and steady base load function. Natural gas is now the dominant contributor to the current power generation sector and in the past year there have been periods where coal has not played a role at all.  Back in 1989 coal made up most of the generating capacity. Oil demand within the UK has hardly changed over thirty years (slightly up) although production has halved.

As noted above, one feature that has surged since 2016 is the proportion of renewable energy in the generation mix. Recent figures from BEIS show that wind and solar have now exceeded nuclear on a quarterly basis.

In the final energy system, the changes are more nuanced. The overall share of electricity has moved from 16.7% of final energy to 20.4%, or a shift of 3.7% points in 27 years. The global rate of change is tracking at 2% points per decade, so the UK is well short of that pace of transition. A net zero emissions economy would likely need electricity to be the major component of final energy, say around 60%, so the UK rate of change will need to shift from 1.37% points per decade to around 11% points in each of the coming decades.

Transport hasn’t shifted at all in the past 30 years, with oil use in transport slightly increasing. Electricity is just starting to creep into this mix, but pure electric vehicles have reached only 0.7% (2018) of new car sales. Worryingly, the total number of petrol and diesel cars registered in the UK in 2018 was unchanged from 2013, a period which has seen the first major push to get consumers to go electric. Reaching net-zero emissions by 2050 will not just mean seeing all new purchases as electric, but seeing all new purchases from about 2035 onwards as electric. It can take up to 15 years to completely turn over the entire on-the-road fleet, although a future government could presumably accelerate this process with a buy-back-and-scrap scheme.

In the industrial sector, energy consumption has dropped by nearly a third, presumably through efficiency improvements as industrial output has hardly changed (see chart below). Importantly, electricity use has stayed largely the same. This means that the sector is gradually electrifying, although again the pace of change is below that required.
UK Industrial Production (1970-2019).

Then there are the tricky bits, where the UK has made only limited progress. The CCC notes that radical change is needed in home heating, including a shift to hydrogen and heat pumps, with support from much better home insulation. But residential natural gas use has marginally increased in 30 years, despite significant improvements in boiler efficiency and the use of electricity instead of gas for new apartment buildings. One highlight in this area is the recent milestone of one million homes now being supplied with biomethane.

The overall change in 30 years has been one of continually falling greenhouse gas emissions, with much of the gain coming from natural gas replacing coal and a fall in industrial energy use. While the impetus for change over the last 30 years was perhaps not as great as it is now, the overall shift is symptomatic of typical energy system dynamics; rapid adjustment has never been a feature, primarily due to the large capital stock involved. Outside the energy sector change over the same period has been dramatic. In 1989 there was no internet, no social media, hardly a mobile phone to be seen and televisions were defined more by their depth than their width. So can the UK reach these sorts of transition rates and achieve the goal of net-zero emissions by 2050?

In the power generation sector, zero emissions should be entirely achievable in that time frame. Renewables are surging and new nuclear capacity is now under construction (although even getting that started took a decade). Similarly, with the models on offer or on their way, passenger vehicles could be entirely electric and various cities across the UK have demonstrated that electric buses are now a viable option. But there is no real sign of change for heavy goods vehicles, shipping or aviation. Perhaps the biggest challenge sits with the use of natural gas in homes and industry. It is easy to use, clean, provides a very high heat load and is backed by extensive infrastructure. Hydrogen and electrification are potential pathways forward, but as noted the electrification rate of change has to shift by nearly an order of magnitude. For hydrogen there are promising signs of change with the government now funding a major programme on supply and conversion of existing facilities away from natural gas.

Finally, there is carbon capture and storage (CCS), which may be a simpler solution in many applications than attempting to dislodge natural gas. CCS in combination with direct air capture (still a nascent technology) may also be needed to balance out emissions in sectors such as aviation. Even the production of hydrogen may be easiest at scale from natural gas, which would then also require CCS. The UK has tried and tried again with CCS, but there is still no operational facility to show for all the efforts made. Yet the UK is both pipeline dense and geologically gifted in terms of storage potential, so deployment could proceed given the right incentives to begin.

The Climate Change Committee have put forward a bold recommendation, but it is not without immense challenge. It ought to be possible to achieve the 2050 goal of net-zero emissions, but it won’t happen without some significant nudging by the government in a number of key areas. Policy decisions over the coming five years may well set the scene for the next twenty, so there is everything to play for.