A sharp reduction in personal travel, including commuting to work, drove household greenhouse gas emissions down by 15 million tonnes of carbon dioxide (CO2) equivalent in 2020. This drop is equivalent to about 3% of total emissions in 2019.
CO2 equivalent is a measure of the combined global-warming potential of various greenhouse gases, including methane and nitrous oxide as well as carbon dioxide.
With many people working remotely, being on furlough, or losing their job in 2020, more people were staying at home using energy for heating. However, these additional emissions were more than offset by the drop in travel emissions.
With reduced industrial emissions, households have been the single biggest emitter of greenhouse gases in the UK since 2015. Both the energy and manufacturing sectors have reduced emissions significantly over the last decade, while household emissions have remained relatively high. This has increased interest in reducing household emissions to help cut overall emissions to “net zero” by 2050.
Net zero would mean that total UK emissions would be equal to or less than those removed from the environment, achieved by a combination of reduction and removal of emissions.
While a move to greater long-term homeworking may see transport emissions fall, other activities could push emissions back up and even reverse the effect.
Most people (85%) who worked from home during the pandemic expect to use a “hybrid” approach of both home and office work in the future, according to the Opinions and Lifestyle Survey. Another 4% expect to work only from home.
If you have started travelling in to work less often, you can explore how this might affect your carbon footprint with our interactive tool.
Total household emissions - including personal transport, and heating and other activities – fell from 148 million tonnes of CO2 equivalent in 2019 to 133 million tonnes in 2020, as total UK emissions fell from 552 million tonnes of CO2 equivalent to 481 million tonnes.
The 10% drop in household emissions is the second greatest annual reduction since the Office for National Statistics (ONS) first aggregated them in 1990. Only 2011 saw a greater reduction when household emissions fell 12%, possibly caused by 2011 being one of the warmest years on record.
Last year’s drop of 15 million tonnes in household emissions is roughly the same as the CO2 produced by one and a quarter years of coal use at the UK’s pre-pandemic rate of consumption.
Household emissions come primarily from heating the home and personal transport, such as commuting and recreational travel. Between 2019 and 2020, household emissions not relating to travel, which are mostly heating emissions, increased 1.5% from 80 million tonnes CO2, equivalent to 81 million tonnes.
But the same period saw household transport emissions (not including industrial transport) drop 24%, from 68 million tonnes CO2 equivalent to 52 million tonnes. This is by far the greatest drop seen in such emissions since the series began in 1990.
The 16 million tonne fall in transport emissions means just under one quarter (23%) of the total drop in UK emissions in 2020 was because of changes in personal travel.
Particulate matter air pollution also fell significantly and it may be the improvement in air quality that many people noticed during the lockdowns.
PM2.5, which is made up of particles less than 2.5 micrometres in diameter, pose a serious risk to human health. Research suggests that PM2.5 may lead to a loss of six months of life expectancy from birth for UK residents.
PM2.5 levels were down 7% across the UK, from 114 thousand tonnes in 2019 to 107 thousand tonnes in 2020. There were also drops in other air pollutants, such as PM10 (down 8%), carbon monoxide and benzene (both down 6%).
Recently released ONS data on household spending seems to reinforce the notion that the drop in transport emissions was driven partly by the increase in home working.
As we might expect, households spent less on travel and more on housing, fuel and power. This shift was more pronounced among the highest income households – the members of which are more likely to work in jobs that can be done from home.
Households in the lowest 20% income group went from spending a weekly average of £34.90 on transport in 2019 to £27.10 in 2020, a 22% drop. In the same period, the highest-earning 20% went from spending £141.80 per week on transport to £94.50, a 33% drop.
For the lowest income households, spending on housing, fuel and power went down slightly from £70.20 to £69.10 per week, while the highest income households increased spending from a weekly average of £98.40 in 2019 to £104.00 in 2020.
The shift in spending on housing, fuel and power may be because higher income households were more likely to work from home but may also be because higher income households are more likely to live in larger properties that can cost more to heat.
The increase in home working represents only one of many dynamics that will determine the overall environmental impact of COVID-19.
These data suggest that households and the broader economy have made substantial changes during 2020. Some may have also felt an increased dependence on the natural world, with over 40% of respondents to a Natural England survey saying green spaces had become more important to their wellbeing since the beginning of the pandemic.
But many of the changes that have been made - and are still being made - are hard to quantify from an emissions perspective. Greenhouse gases produced to heat homes and for personal travel remain a considerable proportion of UK emissions, and it will be interesting to see how trends develop in the provisional figures for 2021 this time next year and to undertake further analysis to help inform policy and the public in this area.