Unprecedented decline in CO2 emissions
Covid-19 has a massive impact on global emissions, the first half of 2020 saw an unprecedented decline in CO2 emissions – larger than during the financial crisis of 2008, the oil crisis of 1979, or even World War II, the Potsdam Institute for Climate Impact Research (PIK) reported in October 2020. Thus, in the first six months of this year, 8.8 per cent less carbon dioxide was emitted than in the same period in 2019 – a total decrease of 1551 million tonnes. Nevertheless, the impact on the long-term CO2 concentration in the atmosphere is meagre.
In April, at the height of the first wave of Corona infections, when most major countries shut down their public life and parts of their economy, emissions even declined by 16.9 per cent. Overall, the various outbreaks resulted in emission drops that we normally see only on a short-term basis during holidays such as Christmas or the Chinese Spring Festival.
The greatest reduction of emissions was observed in the ground-transportation sector. 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 researchers also found strong rebound effects. With the exception of a continuing decrease of emissions stemming from the transportation sector, by July 2020, as soon as lockdown measures were lifted, most economies resumed their usual levels of emitting CO2. But even if they remained at their historically low levels, this would have a rather minuscule effect on the long-term CO2 concentration in the atmosphere.
Thus, the researchers stress that the only valid strategy to stabilise the climate is a complete overhaul of the industry and commerce sector. “While the CO2 drop is unprecedented, decreases of human activities cannot be the answer,” says Hans Joachim Schellnhuber, founding director of the Potsdam Institute for Climate Impact Research. “Instead we need structural and transformational changes in our energy production and consumption systems. Individual behaviour is certainly important, but what we really need to focus on is reducing the carbon intensity of our global economy.”
Read more at PIK website