- Quarantining and lockdowns have forced many countries' industries to shut down, with many factories closing their doors.
- Nitrogen dioxide emissions are a major air pollutant, and are closely linked to factory output and vehicles on the roads.
- NO₂ emissions can be a good indicator of global economic activity—and the changes are visible from space.
The Emissions Impact of Coronavirus Lockdowns
There’s a high chance you’re reading this while practicing social distancing, or while your corner of the world is under some type of advised or enforced lockdown.
While these are necessary measures to contain the spread of the COVID-19 pandemic, such economic interruption is unprecedented in many ways—resulting in some surprising side effects.
The Evidence is in NO₂ Emissions
Nitrogen dioxide (NO₂) emissions, a major air pollutant, are closely linked to factory output and vehicles operating on the road.
As both industry and transport come to a halt during this pandemic, NO₂ emissions can be a good indicator of global economic activity—and the changes are visible from space.
These images from the Centre for Research on Energy and Clean Air (CREA), as well as satellite footage from NASA and the European Space Agency (ESA), show a drastic decline in NO₂ emissions over recent months, particularly across Italy and China.
NO₂ Emissions Across Italy
In Italy, the number of active COVID-19 cases has surpassed China (including the death toll). Amid emergency actions to lock down the entire nation, everything from schools and shops, to restaurants and even some churches, are closed.
Italy is also an industrial hub, with the sector accounting for nearly 24% of GDP. With many Italians urged to work from home if possible, visible economic activity has dropped considerably.
This 10-day moving average animation (from January 1st—March 11th, 2020) of nitrogen dioxide emissions across Europe clearly demonstrates how the drop in Italy’s economic activity has impacted the environment.
Source: European Space Agency (ESA)
That’s not all: a drop in boat traffic also means that Venice’s canals are clear for the time being, as small fish have begun inhabiting the waterways again. Experts are cautious to note that this does not necessarily mean the water quality is better.
NO₂ Emissions Across China
The emissions changes above China are possibly even more obvious to the eye. China is the world’s most important manufacturing hub and a significant contributor to greenhouse gases globally. But in the month following Lunar New Year (a week-long festival in early February), satellite imagery painted a different picture.
NO₂ emissions around the Hubei province, the original epicenter of the virus, steeply dropped as factories were forced to shutter their doors for the time being.
What’s more, there were measurable effects in the decline of other emission types from the drop in coal use during the same time, compared to years prior.
Back to the Status Quo?
In recent weeks, China has been able to flatten the curve of its total COVID-19 cases. As a result, the government is beginning to ease its restrictions—and it’s clear that social and economic activities are starting to pick back up in March.
With the regular chain of events beginning to resume, it remains to be seen whether NO₂ emissions will rebound right back to their pre-pandemic levels.
This bounce-back effect—which can sometimes reverse any overall drop in emissions—is [called] “revenge pollution”. And in China, it has precedent.— Li Shuo, Senior climate policy advisor, Greenpeace East Asia