Can the UK reach net zero using current technologies?

The report, Zero Carbon Britain: Rising to the Climate Emergency, models the changes to energy, buildings, transport, industry, diets and land use that could reduce energy demand by 60%, provide 100% renewable energy, and cut emissions from agriculture and industry whilst creating natural carbon capture through reforestation and peatland restoration.

This combination of ‘powering down’ energy use through increased efficiency and behaviour change, ‘powering up’ clean renewable energy supplies, and transforming land use could allow the UK to reach net zero greenhouse gas emissions without relying on as yet unproven technologies, such as carbon capture and storage or direct air capture.

Paul Allen, Project Coordinator said: “Relying on speculative future technology to get to net zero risks overshooting the remaining carbon budget, resulting in the very real possibility of global temperature rises of 2°C or more.

“By modelling a zero carbon scenario using only technology that is ready to be rolled out at scale, CAT’s research shows that there is no good reason to take this risk. We have the technology to combat climate change, and we can start today.”

Powering down energy use

Changes to buildings, transport and industry could help to reduce UK energy demand by 60%.

Key features of the Zero Carbon Britain model include:

• Buildings: having high ‘Passivhaus’ standards for new buildings, retrofitting all existing buildings, and improving internal temperature control could reduce energy demand for heating by around 50%.
• Transport: reducing how much we travel, and changing how we travel - with more use of public transport, walking, cycling, switching to efficient electric vehicles and two thirds less flying - could reduce energy demand for transport by 78%.

Powering up clean energy supplies

The report shows how it is possible to supply 100% of the UK’s ‘powered-down’ energy demand with renewable and carbon neutral energy sources, without fossil fuels or nuclear.

In the Zero Carbon Britain energy scenario:

• Many different renewable energy sources suited to the UK - solar, geothermal, hydro, tidal and others - are used to produce electricity and heat, with wind energy providing around half of the energy supply.
• Most of the energy in the scenario (around 66%) is provided as electricity.
• Carbon neutral synthetic fuels play an important role where it is not possible to use electricity - for example, in some areas of industry and transport, and as back up for the energy system.

Matching supply and demand

To ensure that energy is available at all times, CAT researchers looked at ten years of real weather data to examine how much energy could be captured by renewable energy systems. By matching this to ten years of energy demand patterns, adjusted to take account of the modelled energy savings, researchers were able to plan for possible shortfalls.

The hourly modelling shows a surplus of energy 74% of the time, with energy provided at other times by shifting demand using smart appliances and by storing energy.

Batteries, pumped storage and heat storage can be used for short term energy storage over hours or days, whilst hydrogen and carbon neutral synthetic gas (which can be dispatched quickly into the electricity grid when needed) can be used for long term energy storage over weeks or months.

Transforming land and diets

The report explores how dietary change (particularly switching from meat and dairy to plant-based proteins), food waste reduction and improved agricultural practices could help with the transition to zero whilst providing a healthy diet for the whole UK population.

Key features include:

• Reducing ‘on-farm’ greenhouse gas emissions by 57% from 2017 levels.
• Reducing UK food imports from 42% to 17%, and so reducing the impacts elsewhere in the world of food production for our consumption.
• Repurposing 75% of the land currently used for grazing livestock, freeing up space for a range of other uses, including doubling UK forest area and restoring 50% of UK peatlands to help mop up residual emissions.

Additional benefits

The report highlights the multiple additional benefits that these changes offer, including improvements to health and wellbeing via better diets, more exercise, improved air quality and a reduction in fuel poverty. Other benefits include the creation of green jobs and an increase in biodiversity both through tackling climate change and through freeing up land to allow nature to thrive.

CAT Chief Executive Officer, Peter Tyldesley said: “CAT’s research shows how the UK could achieve net zero greenhouse gas emissions in a way that also helps improve our quality of life and enhances biodiversity. What’s now urgently needed is a UK Zero Carbon Action Plan with policy frameworks and large-scale investment to support the roll out of these solutions as quickly as possible.”

You can download the report below.