As vaccinations against COVID-19 become more widespread, and without losing sight of the fact that the pandemic still has a long way to go, it is nonetheless worth remembering that we still have a pre-existing problem whose urgency has not diminished: environmental degradation, and in particular climate change. It seems clear that the global coronavirus epidemic will also influence the state of the planet’s health in one way or another. As the headline of an editorial in The Lancet last December put it, COVID-19 and climate are “converging crises”. But once humanity has succeeded in subduing the former, what will be the outcome on the latter: will the pandemic produce a healthier or sicker environment?
In April 2020, as human activity was mostly shut down during the first wave of the pandemic, OpenMind reported on the immediate environmental impacts observed, including a reduction in the rate of CO2 emissions in both China and Europe. The Carbon Brief website predicted the largest annual decline in CO2 emissions, a cut of 2,000 megatonnes —5.5% of the 2019 total— and some analysts stressed that this improvement in air quality could alleviate the burden of mortality from pollution. More recent estimates have put the cut in global emissions in 2020 at 7% of the previous year.
Changes in environmental indicators
There are indications that some changes have persisted beyond the initial peak. At the autumn meeting of the US Geophysical Union last December, researchers from several institutions presented satellite observations suggesting changes in certain environmental indicators. Deforestation has increased in the Brazilian Amazon, Indonesia and Congo, while it has decreased in Colombia and Peru. Air pollution has decreased; for example, India has seen a one-third to one-quarter reduction in PM10 airborne particulate matter. Cleaner air has resulted in snow that is whiter in some regions than at any time in the past 20 years, reducing the heat absorbed by the Earth. On the other hand, in places like New York, water turbidity has dropped by more than 40%.
“The environment is quickly changing,” the researchers summarised. And while they cannot be sure that the observed changes are a direct consequence of the pandemic, they point out that the decline in mobility that has lasted for months may explain some of the effects detected; however, they warn, all this will quickly vanish if any of the trends brought about by the pandemic, such as the increased spread of teleworking, are reversed. Overall, experts agree that any potential environmental gains resulting from the COVID-19 catastrophe will only be short-lived unless ways can be found to sustain the positive changes.
But as the European Environment Agency (EEA) points out, not all impacts are beneficial. In contrast to the potential gains in terms of reduced emissions and pollution, one aspect that has been of concern since the start of the pandemic is the increase in waste generation, especially plastics: the global economic slowdown caused by the pandemic caused oil prices to plummet, in turn encouraging the production of new plastics as opposed to recycling. This has been coupled with a global increase in the consumption of packaging and other single-use plastics, along with a meteoric rise in demand for disposable protective items such as face masks. Initiatives are already emerging to recycle this waste: researchers at RMIT University in Australia have devised a method to recycle surgical masks into road-building material and construction concrete; three million masks can be used to build one kilometre of two-lane road, avoiding the generation of 93 tonnes of waste.
Risk of the emergence of zoonotic viruses
But from a broader perspective, the relationship between pandemics and the environment is a two-way street: “societal resilience depends on a resilient environmental support system,” says the EEA, emphasising how a healthier environment also contributes to the health of humanity, as dictated by the current One Health approach. Studies have warned that biodiversity loss and ecosystem destruction bring previously separated species into contact with each other and with humans, increasing the risk of the emergence of zoonotic viruses.
In fact, a recent study suggests that this is not a future danger, but a very present one: according to the authors, climate change has increased the diversity of bats in the Asian region where the ancestors of SARS-CoV-2 and its relative SARS-CoV-1 have presumably emerged. “Climate change may have been an important factor in the outbreaks of the two viruses,” the authors propose, although a direct link is still a matter of debate. Finally, poaching, trafficking of species and their sale in markets may also contribute to these zoonoses. The COVID-19 pandemic has spurred greater interest in increasing the controls surrounding these potential sources of emerging infectious diseases.
Our carbon budget decreases
Ultimately, experts point out that it is too early to know whether and to what extent a phenomenon of a magnitude unprecedented in a century, which aptly describes the current pandemic, will produce any net environmental damage or benefit in the long term. But without waiting to know the answer, they have already warned that even a reduction in emissions means that the amount of CO2 in the atmosphere continues to grow, and thus our remaining carbon budget, the amount we can still emit while limiting the temperature rise to a particular target, continues to shrink.
In particular, a new study estimates that at the current rate of emissions we will exhaust this budget for the most stringent target of the 2015 Paris agreement —1.5°C maximum global temperature increase— in just over a decade. Experts are urging a green recovery from the pandemic, but according to the United Nations Environment Programme (UNEP), economic recovery stimuli are squandering the opportunity, for example by neglecting investment in clean energy. As The Lancet editorial stresses, decisions taken now must address the health, social and economic crisis as well as the environmental one; “aligning responses presents an opportunity to improve public health, create a sustainable economic future, and better protect the planet’s remaining natural resources and biodiversity.”