Living Carbon Free
Published: 2 May 2019

Exploring what a net-zero target means for households

What does a Net-Zero carbon emissions future look like in 2050 for the average UK household?

Analysis by Energy Systems Catapult for the Committee on Climate Change explored what is means to cut carbon in UK households by 80%, >90% and 100% (Net-Zero) compared to 1990 level, across six activities: heating, transport, electricity, aviation, diet and waste.

We found that a net-zero future would require more lifestyle changes for transport, diet and air travel. But the most significant change would relate to how people heat their homes.

Introduction

The UK Climate Change Act 2008 set a legally binding target of reducing greenhouse gas emissions by 80% by 2050 compared to a 1990 baseline. Seen as a proportionate UK response to global efforts to prevent temperatures rising 2°C above pre-industrial levels.

Since that time, improved scientific understanding of the risks of climate change means attention has shifted to a more ambitious target of limiting warming to 1.5°C. To succeed, we need to eliminate net[1] GHG emissions globally by the second half of the century.

The UK Government has asked the Committee on Climate Change (CCC) to advise on an appropriate target date for the UK to achieve net zero emissions, and whether this requires accelerated reductions between now and 2050.

In this supporting analysis, Energy Systems Catapult has explored net zero from the point of view of households.

Counting Carbon

As part of a global economy, many of the goods and services we consume in the UK are imported from overseas, while many of the goods and services produced by our national economy are destined for consumers elsewhere. Allocating responsibility for the emissions associated with these activities can be done in two ways.

The production perspective puts responsibility for emissions onto the country where they physically arise. This could occur when heating homes with gas, fuelling cars with petrol or when emissions arise during industrial production of goods and services – even when some of those goods are exported overseas. At the same time, this approach ignores emissions arising overseas in the production of goods and services that are imported to the country.

The consumption perspective places accountability on the final consumer not the producer. Regardless of where emissions physically occur along the global supply chain, responsibility is allocated to the country where the goods and services are ultimately destined to be consumed.

For a household looking to understand its emissions impact, the consumption perspective is a natural fit. For a national government interested in target setting, inevitably the focus is on territorial emissions over which that government has jurisdiction. Accordingly, the UK Climate Change Act adopts the production perspective.

Energy Systems Catapult explored how UK households can play their part in meeting a national net zero target set on a production basis. But addressing climate change is a global challenge so it makes sense to keep track of the emissions from households on a consumption basis too[2].

At a national level, this can help to ensure we don’t solve the UK emissions challenge by simply offshoring our emissions intensive activities like heavy industry and food production. At a household level, it would help us all understand the true impact of our activities and allow us to identify opportunities to make more sustainable choices.

Household emissions

The CCC have provided analysis of the potential for emissions reduction in different sectors of the economy. Here we have considered the implications for households across a set of six activities:

  • Heat (emissions from energy for space and water heating in residential buildings)
  • Transport (emissions from cars, buses, trains, excludes commercial fleets, goods vehicles)
  • Electricity use (emissions from generation of electricity for domestic consumption)
  • Aviation (emissions from domestic and international air travel, excluding business travel)
  • Diet (aligned with emissions from UK agriculture and land use)
  • Waste (emissions from waste management, excluding share from commercial waste)

Most of these activities map well with a production perspective, as they relate to emissions which are domestic by their nature. The exception is diet, where the CCC advice relates to UK agriculture and land use emissions, even though we know that food products are extensively imported and exported as part of a global market. We have tried to give a general sense of how actions by UK households could contribute to UK (and global) emissions reductions.

We have disregarded emissions arising from energy use for commercial and industrial purposes. From a consumption perspective, these emissions occur due to household demand for goods and services, but for our purposes we have treated these as out of scope.

The six activities above are explored in the following sections. For each one we examine:

  • The story so far (changes in emissions between 1990 and 2017)
  • Actions for decarbonisation (including upstream as well as household level actions)
  • Core scenario – made up of low-cost low-regret options that make sense under most strategies to meet the current 80% 2050 target. They also broadly reflect the Government’s current level of ambition.
  • Further Ambition scenario – includes more challenging options, and on current estimates generally more expensive than the Core options. Further Ambition gets us to 96% reduction.
  • Net-zero – the CCC highlight several more ‘Speculative’ options which could be used to achieve a net-zero target, on top of the Further Ambition measures. The approach represented here assumes some of the CCC’s Speculative demand and land-led measures are used to achieve 100% emissions reduction. (The extra 4% could instead be achieved through e.g. further greenhouse gas removals).

The emissions are calculated on a per household basis (assuming 35 million households in 2050 compared to around 29 million today) [3].

[1] Achieving net zero means balancing any remaining emissions with an equal quantity of carbon removed from the atmosphere.

[2] DEFRA, UK’s carbon footprint, https://www.gov.uk/government/statistics/uks-carbon-footprint

[3] Historical household emissions from heating and electricity determined from domestic energy consumption and associated GHG conversion factors and average national supply intensities. Household transport and aviation emissions determined from statistics on national GHG emissions from all modes of transport with a proportion removed for business, commercial, and industrial use. Waste emissions determined by attributing an appropriate proportion of UK waste management GHG emissions to households and the proportion of agriculture emissions were used as a proxy for diet emissions. Sources include: BEIS, ECUK tables 3.01, 3.02, 3.23; Final UK greenhouse gas emissions national statistics 1990-2017 Table 3. Defra/DECC, GHG Conversion Factors for Company Reporting, Tables 1c, 1d, 9c. CCC, Reducing UK emissions – 2018 Progress Report to Parliament, 2018, Supporting data Table 2.2. DfT, National Travel Survey, Tables NTS0410, TSGB0208 (AVI0108). CAA, 1991 Passenger Survey Report – Gatwick, Heathrow, Luton, Stansted & London City. DCLG, Household projections for England and local authority districts.