While a pollution-free period hasn’t averted climate change, the recovery offers a chance for health and nature, a study reveals

A post-lockdown economic recovery plan that incorporates and emphasises climate-friendly choices could help significantly in the battle against global warming, according to a new study.

This is despite the sudden reduction of greenhouse gas emissions and air pollutants, seen when many industries stopped and people stopped driving and flying during lockdown, having a negligible effect on rising global temperatures.

The study authors warn that even with some lockdown measures staying in place to the end of 2021, without more structural interventions global temperatures will only be roughly 0.01°C lower than what they currently expect to see by 2030.

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

However, the international study, led by the University of Leeds and supported by Imperial College London’s Dr Joeri Rogelj, estimates that including policies to cut greenhouse gas emissions as part of an economic recovery plan that prioritises growth in low-carbon industries and jobs could prevent more than half of the warming expected by 2050 under current policies.

This would provide the possibility of global temperatures staying below the Paris Agreement’s aspirational 1.5?C global warming limit and avoiding the greater risks and more severe impacts, such as droughts, flooding and storms, that higher temperatures will bring.

Research co-author Dr Joeri Rogelj, Lecturer in Climate Change and the Environment at the Grantham Institute at Imperial College London, called the results "both sobering and hopeful".

"The flash crash in global emissions due to lockdown measures will have no measurable impact on global temperatures by 2030; but 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. Out of this tragedy comes an opportunity, but unless it is seized a more polluting next decade is not excluded," he said.

The change in nitrogen oxides air pollution during lockdown

Global data on peoples' movements

The study's lead author, Professor Piers Forster from the University of Leeds began working with his daughter, Harriet, after her A levels were cancelled. They analysed the newly accessible global mobility data from Google and Apple.

They calculated how 10 different greenhouse gases and air pollutants changed between February and June 2020 in 123 countries. They then brought in the wider team, including Dr Rogelj, to help with the detailed analysis.

The team’s findings, published today in Nature Climate Change, detail how despite carbon dioxide (CO2), nitrogen oxides (NOx) and other emissions falling by between 10-30% globally through the massive behavioural shifts seen during lockdown, there will be only a tiny impact on the climate, mainly because the decrease in emissions is 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 move towards a more resilient, net-zero emissions future.

The change in sulphur dioxide air pollution during lockdown

Professor Forster, director of the Priestley International Centre for Climate at Leeds, said: “The choices made now could give us a strong chance of avoiding 0.3?C of additional warming by mid-century, halving the expected warming under current policies. 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.”

Study co-author Harriet Forster, who has just completed her studies at Queen Margaret’s School in York, said: “Our paper shows that the actual effect of lockdown on the climate is small. The important thing to recognise is that we’ve been given a massive opportunity to boost the economy by investing in green industries - and this can make a huge difference to our future climate.

“I’m going to London next month to study art but I also did chemistry at A-level so was glad to use what I learned in my chemistry classes to do something useful.”

A net-zero emissions economic recovery from COVID-19

A recent briefing paper from Imperial's Grantham Institute and collaborators identifies key recovery policies that the UK government could introduce to both respond to the crisis of COVID-19, and support the country in meeting its commitment to reaching net-zero emissions by 2050.

It has been produced in association with the COP26 Universities Network, a growing group of more than 30 UK-based universities working together to help deliver an ambitious outcome at the UN Climate Summit in Glasgow and beyond.

Read the full report on the Grantham Institute’s website.

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'Current and future global climate impacts resulting from COVID-19' is published in Nature Climate Change.

Header image: Along among, by James Guppy (CC BY-NC-SA 2.0)

Animations created by Dr Robin Lamboll, Research Associate in Climate Science and Policy at the Grantham Institute.