How will coronavirus impact the environment?

The COVID-19 pandemic is devastating. By the time it is over, millions of people will have lost loved ones and the economic repercussions are inevitably going to be huge. But recently, the state of the environment has also been brought up in discussion. How has the climate been affected by the coronavirus outbreak, and what will the environment look like as a result of it?

Hidden amongst all the bad news, we have all seen online footage of places being supposedly “reclaimed” by nature: fish visible in the canals of Venice, wild boar roaming the streets of Bergamo and China’s long-lost blue skies revealed due to dramatically reduced CO2 emissions. All are attributed to the situation surrounding the current COVID-19 pandemic. In the present doom and gloom, is this the sign of a silver lining, something positive on which we can focus? The answer may not be so simple.

A reduction in greenhouse gas emissions

China’s CO2 emissions were cut by around 25% over the initial four-week period of the pandemic, roughly 200 million tonnes. Much of this came from a reduction in aviation: there were 50-90% fewer flights departing from China and 60-70% fewer domestic flights, compared with pre-pandemic figures. The reduction also partly stems from changes within industry. Many of us have seen the satellite images of China’s lessened nitrogen dioxide levels, which are mostly emitted by vehicles, heavy industry and power plants. As we are continually reminded, because CO2 and NO2 are determining factor in planet temperatures, a reduction in these greenhouse gases might lead us to expect a slight decrease in the planet’s temperature.

Unfortunately, that’s probably not going to be the case. In fact, we may see the opposite. According to climate experts, the planet may further warm as a result of the coronavirus pandemic.

The importance of aerosols

This is because industry and transport don’t just emit greenhouse gases – they also release aerosols. An aerosol is essentially anything small and suspended in the air, for example, partially burned fuel from a car’s exhaust, soot from burning coal, as well as organic sources, such a sea salt and pollen.

The relative lack of aerosols over China can be seen clearly in the number of blue-sky days, and in the improvement of air quality (which coincidentally is speculated to have saved more lives than COVID-19 has taken to date). While CO2 absorbs long wavelengths of radiation, causing energy to be “trapped” in the atmosphere, thereby warming the planet, aerosols have the opposite effect. They reflect short wavelengths of radiation, so by adding more aerosols to the atmosphere, sunlight is prevented from reaching the Earth’s surface. This results in a ‘cooling effect’. Thus, removing aerosols from the atmosphere produces a ‘warming effect’. So much for that silver lining.

In short time-scales, the warming effect induced by removing aerosols from the atmosphere is going to outweigh the cooling effect of a slight reduction in CO2 emissions. This means that this year, we will probably see a slight increase above the global expected value. But will this have long-term consequences?

Potentially. It is almost certain that we will see a global recession, perhaps even a shift to depression as a result of the pandemic. This may result in a downturn in economic activity and, implicitly, a downturn in industry. Unfortunately, CO2 emissions aren’t likely to stay low. There are at least three reasons why this isn’t the case.

1. Chinese industry

China’s CO2 emissions have received great attention recently, partly due to COVID-19’s origins, but also because Chinese emissions make up a sizable fraction of global emissions. (see Fig 1)[1]. President Xi Jinping made it very clear that he will put in place ‘aggressive’ measures to stimulate the Chinese economy. Higher investment in heavy industry will result in an increase in the emissions of aerosols and also, unfortunately, CO2. Demand is slowly returning to normal, although at the time of writing, emissions are still 18% lower than usual. NO2 levels have now returned to normal, indicating that current emission levels in both urban areas and industrial centres are close to pre-crisis levels. This predicted bounce back in emissions has a historical counterpart, which leads us to the second reason.

Figure  1: Carbon dioxide emissions from “Our World in data”. Source:

2. The global historical precedent

For many of us, the only event comparable to the economic impact of COVID-19 is the 2008 financial crisis. It therefore seems sensible to start there when thinking about the long-term impacts of the pandemic. In 2009, the year after the financial crisis, global CO2 emissions actually decreased – a dramatic difference compared to previous year-on-year growth. But there is a lag between economic activity and emissions. During 2010, emissions increased more than they would have done in the absence of a financial crisis. Governments around the world responded to the crisis by announcing stimulus packages, measures meant to restore the economy, which often have massive CO2 footprints. For example, the Chinese government announced $586 billion worth of stimulus packages. Within a year, both the economy and the CO2 emissions were back on an upward trajectory. While the 2008-9 financial crisis decreased carbon emissions in the short term, in the long term it actually increased them, and thus had a net negative impact on the climate.

We would therefore expect an increase, or at least a rebound in emissions in 2021. In a best- case scenario, COVID-19 lockdowns will result in a slowing of the rate of increase of emission. The impact may still be tiny compared to the vast amount emitted – around 200 million tonnes of emissions saved at the time of writing, versus about 33 billion tonnes of annual global CO2 emissions. Worst case scenario, there is more carbon emitted in 2021 than there would have been in the absence of a pandemic.

3. The renewable energy transition

It would be fair to say that we are going through, or at least attempting to undertake, a “renewable energy transition” phase. This is the replacing of fossil fuel technologies with lower carbon alternatives, such as wind and solar power, for electricity generation, transport, heating and cooling. Last year, the International Energy Agency (IEA) forecast that 2020 would be a record year for renewable electricity additions: global installations of solar photovoltaics and wind turbines were predicted to out-do 2018 by 20% in terms of energy production. The suspension of industry has been directly detrimental to the installation of new, more carbon efficient energy sources, many of which are made in China (you can see where this is going).

Solar power, in particular, is completely dominated by Chinese manufacturing. As a result of Chinese industry being essentially shut down, so too has the solar industry. It is predicted that the solar sector could lose approximately half its workforce due to the COVID-19 crisis. This is particularly true for companies that rely on residential installations and door-to-door education, involving the kind of in-person contact that social distancing forbids.

In general, it’s safe to say that the renewable energy transition has been at least slowed, if not entirely halted by the pandemic. Every day this transition is delayed is a serious setback if we are to slow global anthropogenic damage.

The list goes on. Entire seasons of scientific data have been lost with closed labs and travel restrictions. There have also been incredibly worrying suspensions to climate protection laws. As well as resulting in an increase in net carbon emissions, the pandemic is causing us to lose valuable time in changing how society is powered.

A silver lining?

Let us look at some potentially positive outcomes instead. Around the world, many sectors are using this opportunity to re-evaluate how we do things. People have demonstrated that despite many novel challenges, they can work effectively from home. It is unlikely that we will come out of this pandemic without significant and lasting societal change.

Will more people work from home?  Most of us are guilty of excessive use of carbon-emitting transport to and from the workplace. Perhaps there will be increasing support for environmental legislation following the footage of blue skies above China’s cities and visible wildlife in Venice’s waters. Smog free skies, leading to both sunnier days and cleaner solar panels have helped solar power break energy-output records in the UK, Germany and Spain this spring. A survey found that 48% of the British public agree that the government should respond to the climate crisis ‘with the same urgency as it has with COVID-19’. Just 28% said that it should not.

This should be seen as a “green light” for governments to be more ambitious in tackling the climate crisis. In the wake of a global recession, we might see the renewable energy transition accelerate, as only the most “economical” of decisions will be tolerated by the public (solar plants are on their way to being cheaper to build than the maintenance of old coal-fired power plants).

So, perhaps this is the moment when governments and society will make some positive progress to halt or lessen anthropogenic climate change. I can’t say I whole-heartedly believe this, but I would be pleased to be proved wrong! At the risk of sounding cynical, this pandemic, although enlightening for many, may not be the climate break we hoped for.

Sources and further reading

Title image by Alicia Hayden