Worldwide lockdowns due to the Covid-19 pandemic provided NASA and other institutions new insight into how everyday human activity impacts the atmosphere.
One study led by researchers from NASA's Jet Propulsion Laboratory (JPL) tracked drops in nitrogen oxide emissions during global lockdowns. Nitrogen oxide is commonly produced in car exhaust and from power plants, where it goes on to react in the air to produce ozone. They found about a 2% drop globally in ozone concentrations in the lower atmosphere, a decrease that would be otherwise achievable in about 15 years with even highly aggressive emission restrictions.
A second study focused on carbon dioxide emissions, where they were able to identify local drops and upticks in carbon dioxide emissions, tied with lockdowns and some easing of restrictions months later, respectively. They could also separate local, human-related emissions from those originating from natural sources, such as the 2019-2020 Australian bushfires.



