Locking down emissions
Greenhouse gases have dropped in the wake of the pandemic
COVID-19 restrictions led to a big cut in household greenhouse gas emissions last year, as we stayed home and cut back on travel. Figures from the Office for National Statistics show that household emissions - including personal transport, heating, and other activities - fell by 10% from 148 million tonnes of carbon dioxide (CO2) equivalent in 2019 to 133 million tonnes in 2020.
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.
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.
While remote working, furloughs and job losses meant more people were staying at home and using energy for heating, these additional emissions were more than offset by the drop in travel.
Last year household emissions not relating to travel, which are mostly heating emissions, increased 1.5% from 80 million tonnes CO2 to around 81 million tonnes.
But the same period saw household transport emissions drop 24%, from 68 million tonnes CO2 equivalent to 52 million tonnes.
This is by far the greatest drop seen in such emissions since these figures began in 1990.
Particulate matter air pollution also fell significantly, and the ONS said this may have led to the improvement in air quality that many people noticed during the lockdowns.
PM2.5, which is made up of tiny particles, poses a serious risk to human health. Research suggests resulting early deaths may reduce the life expectancy of UK residents by the equivalent of six months.
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%).
The 16 million tonne fall in personal transport emissions means just under one quarter (23%) of the total drop in UK emissions in 2020 was because of changes in personal travel.
Total UK emissions - including industry emissions, as well as household emissions - fell from 552 million tonnes of CO2 equivalent to 481 million tonnes.
Since 2015, households have been the single biggest emitter of greenhouse gases in the UK - with household emissions remaining high despite the energy and manufacturing sectors reducing emissions significantly over the last decade.
This has increased interest in reducing household emissions to help cut overall emissions to “net zero” by 2050, where total UK emissions would be equal to or less than those removed from the environment.
However, while a move to greater long-term homeworking may see transport emissions fall, the ONS said other activities - such as heating homes for longer - could push emissions back up and even reverse the effect.