Hyderabad: The COVID-19 global lockdown has had an "extreme" effect on daily carbon emissions, but it is unlikely to last - according to a new analysis by an international team of scientists.
The study published in the journal Nature Climate Change shows that daily emissions decreased by 17% - or 17 million tonnes of carbon dioxide - globally during the peak of the confinement measures in early April compared to mean daily levels in 2019, dropping to levels last observed in 2006.
Emissions from surface transport, such as car journeys, account for almost half (43%) of the decrease in global emissions during peak confinement on April 7. Emissions from industry and from power together account for a further 43% of the decrease in daily global emissions.
Aviation is the economic sector most impacted by the lockdown, but it only accounts for 3% of global emissions, or 10% of the decrease in emissions during the pandemic.
The increase in the use of residential buildings from people working at home only marginally offset the drop in emissions from other sectors. In individual countries, emissions decreased by 26% on average at the peak of their confinement.
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The analysis also shows that social responses alone, without increases in well being and/or supporting infrastructure, will not drive the deep and sustained reductions needed to reach net zero emissions. Prof Corinne Le Quéré of the University of East Anglia, in the UK, led the analysis. She said: "Population confinement has led to drastic changes in energy use and CO2 emissions. These extreme decreases are likely to be temporary though, as they do not reflect structural changes in the economic, transport, or energy systems.
The team analysed government policies on confinement for 69 countries responsible for 97% of global CO2 emissions. At the peak of the confinement, regions responsible for 89% of global CO2 emissions were under some level of restriction. Data on activities indicative of how much each economic sector was affected by the pandemic was then used to estimate the change in fossil CO2 emissions for each day and country from January to April 2020.
The estimated total change in emissions from the pandemic amounts to 1048 million tonnes of carbon dioxide (MtCO2) until the end of April. Of this, the changes are largest in China where the confinement started, with a decrease of 242 MtCO2, then in the US (207 MtCO2), Europe (123 MtCO2), and India (98 MtCO2). The total change in the UK for January-April 2020 is an estimated 18 MtCO2.
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The impact of confinement on 2020 annual emissions is projected to be around 4% to 7% compared to 2019, depending on the duration of the lockdown and the extent of the recovery. If pre-pandemic conditions of mobility and economic activity return by mid-June, the decline would be around 4%. If some restrictions remain worldwide until the end of the year, it would be around 7%.