Net Zero and the Future Energy Scenarios

Reaching net zero is now almost universally recognised as critical to the future of our society and is a focal point for policies relating to all sectors of the economy. It has changed the focus of FES and will continue to heavily influence decisions made within the energy sector for many years to come. In this chapter, we explain what net zero really means, examine the results of our FES modelling and discuss what they mean for the consumer in each scenario.

A full, detailed version of this section can be found in the 2021 FES document:

FES 2021 interactive document

FES 2021 print ready document

Key insights

  • Leading the Way, Consumer Transformation, and System Transformation reach net zero by 2050.

  • Leading the Way and Consumer Transformation also meet the 6th carbon budget.

  • Leading the Way reaches net zero by 2047 and results in net annual emissions of -28 MtCO2e by 2050 (i.e. 28 MtCO2e are removed from the atmosphere).

  • Steady Progression doesn’t get to net zero, diverging from carbon budgets around 2025 resulting in 243 MtCO2e of annual emissions by 2050.

  • The power sector gets to net negative emissions by 2032 in Leading the Way and Consumer Transformation and by 2034 in System Transformation.

  • Heat and road transport reach zero or almost zero emissions by 2050 across all scenarios except Steady Progression.

  • Some sectors, such as waste and aviation never get to zero emissions by 2050, therefore to reach net zero we need solutions that remove emissions from the atmosphere.

  • Bioenergy with carbon capture and storage (BECCS) is the largest provider of negative emissions in all scenarios that reach net zero, but nature-based solutions like afforestation, reforestation and peak restoration all feature heavily with DACCS also playing a role in Leading the Way. 

  • Lifestyle changes will be needed to reach net zero. Early engagement with consumers is critical.

Total net greenhouse gas emissions


Figure 04 for Net Zero key insights


The three scenarios that meet net zero also meet the 4th and 5th carbon budgets when international aviation and shipping headroom are accounted for, but System Transformation misses the 6th carbon budget (the other net zero scenarios meet the 6th carbon budget). An acceleration in emissions reduction from the mid to late 2030s for System Transformation (partly due to a relatively quick transition from natural gas to hydrogen for residential heating, and negative emissions from hydrogen production) means that it still meets net zero.


Net Zero

What is net zero?

Animals and plants are constantly emitting and absorbing carbon as part of the carbon cycle but human activity such as the burning of fossil fuels and deforestation upset this balance, so that more carbon is emitted than absorbed. Net zero is the target to eliminate the overall human contribution to greenhouse gas emissions. Though we might not be able to stop all greenhouse gas emissions, we can increase the amount being absorbed and stored, either naturally or artificially.

Net zero has become a better-known concept since the United Nations Climate Change Conference in 2015 in Paris, where an agreement was signed to limit global warming to well below 2°C compared to pre-industrial levels. To do this, man-made greenhouse gas emissions need to be at net zero by the second half of the 21st century. Signatories of the agreement also agreed to pursue efforts to limit the temperature increase to 1.5°C, which will require net zero emissions by 2050 at the latest.

Net zero is important because it is now well known that the increase in greenhouse gas emissions (most notably CO2) due to human activity since the industrial revolution is linked to global temperature rise.

How do we get to net zero?

Reaching net zero will mean a fundamental shift in how things are done, both in the UK and around the world, across all aspects of life. Change doesn’t necessarily have to be bad and many aspects of a lower-carbon way of living will be beneficial to individuals, communities and biodiversity.

Our Future Energy Scenarios describe in detail what net zero might be like for the UK in 2050. At a high level, we know that this challenge will need all the following activities and tools to varying extents:

  • Using energy more efficiently

  • Ending unabated fossil fuel use

  • Lifestyle change in a fair way

  • Carbon capture and storage

  • Protection and regeneration of carbon sinks e.g. forests and peatland

  • Financial policies and tools which attribute a cost to the carbon impact of an activity

  • ‘Whole system’ policy, market and regulation decisions

Our scenarios incorporate all these different elements in different ways and the range in results illustrates that there is still a lot of uncertainty about how to decarbonise. There is no one solution for net zero. Our FES analysis directly models the UK energy sector, but other sectors (for example aviation, maritime and land use) emit greenhouse gases so a whole economy view is needed when assessing net zero. For these ‘other’ sectors we’ve used the CCC pathways in their 6th carbon budget analysis as our basis, more detail of the CCC assumptions used are given in the main report.

Reaching net zero

Net zero will only be possible if we start implementing measures now. We can’t wait until 2050. For example, fitting all houses with low-carbon heating, or switching all vehicles away from fossil fuels will take many years and require adequate supporting infrastructure.

All three scenarios that meet net zero see the power sector, led by wind and solar, reaching zero emissions in the early 2030s. A zero carbon electricity supply then contributes to decarbonising heat and transport sectors via electrification (even under System Transformation). Heat, road transport and hydrogen production all see zero or almost zero emissions by 2050, with meaningful emissions reduction levels by 2030 for all three scenarios, but especially Leading the Way. Decarbonisation on the scale and rate seen by any of these three scenarios will require changes not only at a national scale but also on a business and individual level.

These changes will include government policy to promote mass consumer uptake of energy efficiency measures and to drive the transition away from ICE vehicles. Within the industrial and commercial sectors, businesses will be required to invest in energy efficiency measures whilst industry utilises a combination of fuel switching (electricity and hydrogen) and CCUS for those processes which still require natural gas. At an individual level, consumers will need to be more engaged with their energy use, both in terms of how they consume energy (e.g. switching to low carbon heating technologies and EVs) and when they consume it (using "time of use tariffs" when possible, without penalising those who can’t).

Previous analysis suggests that the cost of the energy system out to 2050 only varies a small amount between scenarios, including between those which do and don’t reach net zero. This indicates that technology choices do not impact costs significantly. However, analysis did find that costs are kept lower when consumers are engaged, energy efficiency is pursued, and we have negative emissions in the energy sector.

Future Energy Scenarios

FES 2021 uses the same scenario framework as last year. This is in response to stakeholder requests for consistency and we believe it still allows us to explore the credible range of uncertainty. The ‘Societal Change’ axis combines changes in innovation, understanding and behaviour. All of our FES 2021 scenarios have lower emissions by 2030 compared to FES 2020. Three of those reach net zero by 2050.

Consumer Transformation and System Transformation represent two different ways to reach net zero by 2050 – either by changing the way we use energy or by changing the way in which we generate and supply it.

In Leading the Way, a combination of high consumer engagement and world-leading technology and investment help to enable our fastest credible decarbonisation journey. In this scenario, the UK reaches net zero in 2047 and goes on to reduce emissions by 103% by 2050 (compared to 1990 levels). This would equate to annual net emissions of -28 MtCO2e by 2050, meaning there is a removal of 28 MtCO2e of GHG emissions from the atmosphere annually. To put this in context, total UK emissions in 2018 were 537 MtCO2e. In the same year the UK power sector emitted 66 MtCO2e whilst surface transport emitted 115 MtCO2e.

Decarbonisation happens slowest in Steady Progression, where 2050 emissions are reduced by 73% of 1990 levels. In this scenario, we would be significantly behind the target of net zero, emitting 243 MtCO2e annually by 2050, having diverged from the trajectory needed to meet net zero at around 2025.

FES 2021 explores what these scenarios mean for the consumer and for the energy system in detail.

Four scenarios 2021


Learn more about life in each scenario:

Consumer Transformation

Consumer Transformation – The 2050 net zero target is met with measures that have a greater impact on consumers and is driven by greater levels of consumer engagement. A typical homeowner will use an electric heat pump with a low temperature heating system and an EV. They will have made extensive changes to improve their home’s energy efficiency and most of their electricity demand will be smartly controlled to provide flexibility to the system. The system will have higher peak electricity demands managed with flexible technologies including energy storage, demand-side response and smart energy management

System Transformation

System Transformation – The typical domestic consumer will experience less disruption than in Consumer Transformation as more of the significant changes in the energy system happen on the supply side, away from the consumer. A typical consumer will use a hydrogen boiler with a mostly unchanged heating system and an EV or a fuel cell vehicle. They will have had fewer energy efficiency improvements to their home and will be less likely to provide flexibility to the system. Total hydrogen demand is high, mostly produced from natural gas with carbon capture and storage. 

Leading the Way

Leading the Way – We assume that Great Britain decarbonises rapidly with high levels of investment in world-leading decarbonisation technologies. Our assumptions in different areas of decarbonisation are pushed to the earliest credible dates. Consumers are highly engaged in reducing and managing their own energy consumption. This scenario includes more energy efficiency improvements to drive down energy demand, with homes retrofitted with insulation such as triple glazing and external wall insulation, and a steep increase in smart energy services. Hydrogen is used to decarbonise some of the most challenging areas such as some industrial processes, produced mainly from electrolysis powered by renewable electricity, with no hydrogen production from natural gas.

Steady Progression

Steady Progression – There is still progress on decarbonisation compared to the present day. However, it is slower than in the other scenarios. While home insulation improves, there is still heavy reliance on natural gas, particularly for domestic heating. Electric vehicle (EV) take-up grows more slowly, displacing petrol and diesel vehicles for domestic use; however, decarbonisation of other vehicles is slower with continued reliance on diesel for heavy goods vehicles. In 2050 this scenario still has significant annual carbon emissions, short of the 2050 net zero target.

Energy flows in the four scenarios