The loss of life caused by the coronavirus is undoubtedly a global tragedy, but the behavioral changes people have made in response to the pandemic are a testament to human ingenuity. In a matter of weeks, hundreds of millions of people have completely changed their day-to-day activities in order to protect themselves and others, and these behavioral changes are also having a positive impact on the environment.
Scientists are already observing a decrease in air pollution and greenhouse gas emissions as a result of the pandemic. The latest satellite measurements show a marked decrease in nitrogen dioxide levels over cities and industrial areas in both Asia and Europe. Though not a greenhouse gas itself, NO2 is a precursor for ground-level ozone, which is a harmful pollutant. NO2 is released by cars and industrial processes that also give off many other dangerous pollutants. Here in the Northeast, NASA is reporting a 30% decrease in NO2 levels compared to last March, marking the lowest monthly average recorded since the agency began measuring nitrogen dioxide in 2005.
China, which is the world’s largest carbon producer, saw a 25% decrease in emissions in March and February. In India, residents are seeing a decrease in fine-particulate matter, which is a type of air pollution that has serious impacts on human-respiratory health. The city of New Delhi is usually known for having some of the worst air quality in the world, but in recent weeks the city has had several days that received a “good” air quality rating, which is the highest possible rating.
Atmospheric scientists suspect that these reductions in air pollution are due to the decreased vehicle traffic now that people are working from home, as well as decreased industrial activities. Many also cite the drastic reduction in air traffic for the drop in NO2 levels. The decline in particulate matter in India is also likely due to the halting of construction projects which stir up dust in the air. Regardless of which mechanisms are behind this change, it is clear that pollution is decreasing. Still, the questions remain: are these improvements solely because of the pandemic? Will they have an effect on human and environmental health after the crisis is over?
Some of the improvements in NO2 levels are likely due to seasonal variation. Areas in the northern hemisphere typically experience a decrease in nitrogen dioxide in the early spring as people start heating their homes less or elect to walk or bike instead of drive. This seasonal decline makes it hard to determine how much of the decrease in emissions is because of the pandemic and how much is simply natural variation.
Nevertheless, cleaner air during a pandemic which mainly affects the respiratory pathway is a good thing for at-risk populations. According to Dr. Paul Monks, a professor of air pollution at the University of Leicester, high levels of air pollution can exacerbate viral uptake because it inflames the respiratory system and lowers immunity. The World Health Organization (WHO) is also investigating whether airborne pollution could be a vector for the coronavirus, which would mean that people who live in highly-polluted cities are more at risk. Better air quality could also mean that fewer people are hospitalized for non-coronavirus related issues, freeing up more hospital space for COVID-19 patients.
Though it is a good thing that many cities are seeing declining levels of pollution, this might not be enough to make a difference. A recent study from Harvard found a clear link between COVID-19 patients who experienced long term exposure to air pollution before contracting the disease and higher death rates from the disease. Air pollution is most dangerous when people are exposed to high levels of pollution for an extended period of time. According to the WHO, as many as 7 million people every year die from complications related to air pollution and around 91% of the world’s population is currently breathing air that is considered unsafe. Air pollution also disproportionately affects minorities and people with lower incomes, making it a serious environmental justice issue.
Though less air pollution is valuable in the short term, it is unlikely that these lower levels will be sustained once we return to business as usual. Once social distancing measures are lifted we might still experience lower levels of pollution, but instead due to economic recession. The 2008 recession was accompanied by a measurable decrease in global carbon dioxide levels. During a recession, people are less likely to spend money and therefore are consuming fewer goods and traveling less, resulting in lower carbon emissions.
Nevertheless, the pandemic will eventually run its course, the economy will rebound and the world will more or less return to the way things were, which means the pollution will also reappear. If we continue to travel and consume resources at the same rate we did before, the air pollution and carbon dioxide emissions will not change and eventually the atmosphere will return to its pre-coronavirus state.
There are lessons to be learned from this immense work-from-home experiment. Perhaps in the future, companies will be more accommodating to employees who want to work from home either part-time or full-time. Additionally, this situation might have more people rethinking how they vacation, potentially impacting the airline and cruise industries, which are both major polluters. Though the current low-emissions and low-pollution situation is not permanent, it is providing scientists and politicians with unprecedented data that will help them with future environmental mitigation measures.
Friedman, L. (2020, April 7). New Research Links Air Pollution to Higher Coronavirus Death Rates. The New York Times. https://www.nytimes.com/2020/04/07/climate/air-pollution-coronavirus-covid.html.
Harvey, C. (2020, March 12). How the Coronavirus Pandemic Is Affecting CO 2 Emissions. Scientific American. https://www.scientificamerican.com/article/how-the-coronavirus-pandemic-is-affecting-co2-emissions/.
Martin, C., & Wason, E. (2020, March 20). Environmental Impacts of Social Distancing, National Parks Closed Amid Pandemic, and More. Resources for the Future. https://www.resourcesmag.org/common-resources/issues-environmental-impacts-social-distancing-national-parks-closed-amid-pandemic-and-more/.
Newburger, E. (2020, April 9). Air pollution drops 30% in Northeast US as coronavirus lockdown slows travel: NASA. CNBC. https://www.cnbc.com/2020/04/09/coronavirus-air-pollution-plummets-30percent-in-northeast-us-amid-lockdowns.html.
Pathak, S. (2020, April 10). With Coronavirus Lockdown, India’s Cities See Clear Blue Skies As Air Pollution Drops. NPR. https://www.npr.org/sections/coronavirus-live-updates/2020/04/10/831592401/with-coronavirus-lockdown-indias-cities-see-clear-blue-skies-as-air-pollution-dr.
Watts, J., & Kommenda, N. (2020, March 23). Coronavirus pandemic leading to huge drop in air pollution. The Guardian. https://www.theguardian.com/environment/2020/mar/23/coronavirus-pandemic-leading-to-huge-drop-in-air-pollution.
World Bank Group. Pollution Prevention and Abatement Handbook (rep.). Pollution Prevention and Abatement Handbook.
World Health Organization. Air pollution. World Health Organization. https://www.who.int/health-topics/air-pollution.