Lockdowns to have 'negligible' impact on global temperature, scientists warn

The sudden fall in greenhouse gas emissions and air pollutants recorded during COVID-19 lockdowns will only have a negligible impact on global temperature change, a new study has found.

The researchers forecast that, even with some lockdown measures staying in place to the end of 2021, global temperatures will only be around 0.01°C lower than expected by 2030.

However, the international study, led by the University of Leeds, also found that economic recovery plans with strong green stimuli and climate policies could prevent more than half of the additional warming expected by 2050.

This would provide a good chance of global temperatures staying below the Paris Agreement's aspirational 1.5ÀöC target, according to the researchers, avoiding 0.3ÀöC of extra warming and the associated severe impacts and risks.

“The choices made now could give us a strong chance of avoiding 0.3ÀöC of additional warming by mid-century,“ said study lead author professor Piers Forster. “This could mean the difference between success and failure when it comes to avoiding dangerous climate change.

“The study also highlights the opportunities in lowering traffic pollution by encouraging low-emissions vehicles, public transport and cycle lanes. The better air quality will immediately have important health effects – and it will immediately start cooling the climate.“

The researchers analysed new global mobility data from Google and Apple, and calculated how 10 different greenhouse gases and air pollutants changed between February and June 2020 in 123 countries.

The findings reveal that emissions fell by 10-30% globally due to massive behavioural shifts, such as fewer drivers on roads during lockdowns, but that the impact on temperatures is likely to be tiny because current confinement measures are only temporary.

The researchers also modelled options for post-lockdown recovery, showing that the current situation provides a unique opportunity to implement a structural economic change that could help deliver net-zero emissions.

“The decisions we make this year about how to recover from this crisis can put us on a solid track to meet the Paris Agreement,“ said study co-author Joeri Rogelj from the Grantham Institute – Climate Change and the Environment at Imperial College London.

“Out of this tragedy comes an opportunity, but unless it is seized a more polluting next decade is not excluded.“

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