Net zero – is it feasible?

This week, the Government has accepted the Committee on Climate Change’s (CCC) advice to adopt a new target to reduce its greenhouse gas emissions to zero by 2050. This is a significant step by any measure and makes the UK the first G7 nation to pledge to end its contribution to climate change.

The first question to ask is, is net zero feasible? This question is one that Vivid Economics has been asked an awful lot lately. For example, the CCC requested Vivid to examine the feasibility of a net zero electricity system, examining costs, the supply chain of new renewables and changes to the distribution grid. In 2018, Vivid was asked by WWF to examine feasibility across the whole economy, including the changes required on the land.

In both cases we concluded that net zero is feasible. It is feasible without the use of international offsets (that is, reductions in emissions in other countries compensating for UK emissions) and with the UK’s share of international aviation and shipping included.

To demonstrate feasibility we analyse cost and the practical and technical aspects of rapid change. We also analyse whether similar transitions have been achieved in the past. History tells us that that they have, but that a broad programme of government actions was vital to the success of emerging technologies and systems. This includes new institutions, testing and trialling new technologies and business models at scale. In many cases consistent and long-term policy goals are needed.

Although the net zero legislation is commendable, our work on feasibility very much suggests that target setting is the easy part. Moving new technologies to the point of mass deployment and maintaining high deployment of existing technologies is incredibly challenging. To reach this ambitious goal, we identify three key requirements:

1. Zero emissions in several sectors

Specifically, the power, surface transport and building sectors must reach zero, or near-zero, greenhouse gas emissions by 2050. This can be done with established zero-emissions technologies, such as wind and solar power, heat pumps and electric vehicles, which are all proven at scale, have rapidly growing supply chains and falling costs. However, in some areas, such as heat for buildings, important policy decisions will be needed regarding the mix of technologies to pursue. Rapidly decarbonising the power sector is a crucial part of the jigsaw, as it facilitates the use of clean electricity in buildings and transport.

Cutting building emissions perhaps appears to be the most challenging of these three, and media coverage has been quick to focus on the implications for the use of natural gas in home heating and cooking and the implied level of disruption to millions of households as a result.

A separate report that Vivid Economics did with the UK Energy Research Centre (UKERC) for the Aldersgate Group suggests lessons can be drawn from historical large-scale transitions in heat. The switch from the use of town gas to natural gas in the UK, which took place between 1957-1971 involved the conversion of bulk gas supplies and millions of home appliances. This shows that such transitions are possible (the conversion rate from town gas to natural gas was over 1 million users per year, during the late 1960s and 1970s, similar to what is required to achieve the transition to low carbon heating systems). There is significant scope to learn both from the UK’s past and from examples in other countries.

2. Deep cuts in ‘hard to treat’ sectors

Sectors such as heavy industry are challenging to decarbonise, but we concluded that reaching net zero emissions for industry by 2050 is possible, a finding supported by a separate report from the Energy Transitions Commission, which also addressed heavy duty transport. Although industries like steel will require a complete rebuild of key assets, investments which are likely to require government support, net zero steel can be achieved via a process which first uses hydrogen as a fuel to reduce iron ore before feeding it into electric arc furnaces, which can also be used to repurpose existing steel.

Agricultural emissions also present a unique challenge, not least as the majority of agricultural greenhouse gas emissions are not carbon dioxide; rather, methane and nitrous oxide form the biggest part, mainly from ruminant livestock and the use of fertilisers. A wide range of measures will therefore need to be deployed in the farming sector, including use of greenhouse gas removal or negative emissions options, such as tree planting and habitat restoration, and dietary change will also have a role to play. Nevertheless, the National Farmers’ Union (NFU) has committed to reaching net zero emissions by 2040; as Britain leaves the EU’s Commons Agricultural Policy (CAP), government has an important opportunity to incentivise changes in the farming sector, as Defra has recognised.

International aviation and shipping remain two of the hardest to treat sectors, not least due to their international nature, with incremental rather that transformational changes expected. Nevertheless, emissions reductions can be achieved, for example with biofuels and synthetic fuels or hydrogen, and electrification is also starting to play a role in both.

3. Large scale deployment of greenhouse gas removal (GGR) options

Greenhouse gas removal (GGR) technologies, sometimes referred to as negative emissions technologies, are also essential, as identified in a recent joint report by the Royal Academy of Engineering and Royal Society. Broadly, these fall into two groups; ‘natural’ GGR technologies, such as tree planting and habitat restoration, and technological solutions such as capturing carbon dioxide directly from the air.