In the first half of 2020, the coronavirus pandemic led to an unprecedented decline in CO2 emissions, larger than during the 2008 financial crisis, the1979 oil crisis, or World War II, according to a new study published on 14 October in Nature Communications (1).
The international team of researchers estimate that carbon dioxide emissions decreased by around 9 per cent in the first six months of 2020, compared with the same period in 2019 – a total decrease of 1551 million tonnes – due to lockdown measures, travel restrictions, and other measures implemented by governments around the world to halt the spread of COVID-19, the disease caused by the novel coronavirus (Sars-Cov-2).
At the height of the first wave of coronavirus infections in April, when most major economies shut down to varying degrees, emissions declined by around 17 per cent. These kind of emission drops are typically only seen in the short-term, for example, on holidays such as Christmas. The largest reductions were seen in the transportation sector, with fewer people driving to work and travelling by air.
The near-real-time data were meticulously compiled by the Carbon Monitor research initiative to gain a relatively accurate overview of how much emissions have decreased and the corresponding lockdown measures in each country.
The estimates are based on data from more than 200 countries, including hourly electricity production in 31 countries, daily vehicle traffic in more than 400 cities worldwide, daily global passenger flights, monthly industrial production data in 62 countries, and fuel consumption data for buildings.
In a statement, Prof Daniel Kammen at the University of California, Berkeley explained: “Largely because of working from home restrictions, transport CO2 emissions decreased by 40 per cent worldwide. In contrast, the power and industry sectors contributed less to the decline, with -22 per cent and -17 per cent, respectively, as did the aviation and shipping sectors.”
“Surprisingly, even the residential sector saw a small emissions drop of 3 per cent: largely because of an abnormally warm winter in the northern hemisphere, heating energy consumption decreased with most people staying at home all day during lockdown periods.”
The downside is that once coronavirus lockdowns are lifted, countries rebound back to their normal CO2 emissions. And scientists say that even if the historically low emissions levels were to continue, the effect on long-term CO2 concentrations in the atmosphere would be negligible.
The authors emphasize that individual behaviour – while certainly important – is not the answer to our climate woes. Although the drop in CO2 emissions is ‘unprecedented, a complete overhaul of the global energy production and consumption systems is required to achieve lasting changes in atmospheric CO2 levels.
The new analysis offers a precise glimpse at both the impact of COVID-19 on global energy consumption to date and valuable insights into basic steps required to reduce emissions in the post-pandemic future.
“It’s a big deal that our method allows us to monitor emissions on a practically daily basis. We can even see the effects of weekends and holidays for the first time,” said co-author Prof Steve Davis at the University of California, Irving. “And going forward, this will be a powerful tool for tracking the greenness of the COVID-19 economic recovery initiatives and other efforts to reduce emissions.”
(1) Liu, Z. et al. Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic. Nature Communications (2020). DOI: 10.1038/s41467-020-18922-7