Posted on May 12, 2020 by Todd E. Palmer
NASA’s Earth Observing System Project gathers data from a fleet of satellites orbiting the planet. This system of satellites is playing an increasingly important role in measuring air pollution and informing regulatory policy on a global scale. Dr. Tracey Halloway at the University of Wisconsin – Madison leads the NASA Health and Air Quality Applied Sciences Team (HAQST) which is doing extensive research in this area. HAQST is staffed by air quality and public health scientists from government offices and universities across the country. Their wide-ranging projects include measuring and tracking global pollution levels, climate change indicators, and regional haze. HAQST has created a website summarizing available satellite resources which can be accessed by stakeholders and the general public for making better informed air pollution policy decisions. I encourage those of you with an interest in this area to explore the research being undertaken by this group.
Most recently, NASA released satellite data documenting the dramatic reduction in nitrogen dioxide (NO2) emissions measured in the United States since shelter-in-place orders went into effect to quell the COVID-19 pandemic. This data was collected from instruments on NASA’s Aura and the European Space Agency’s Sentinel-5 satellites. NASA has compared the average levels of ambient NO2 experienced in the United States between March 2015 through 2019 with those experienced in March 2020. The comparison is striking:
These reductions, ranging from 30% to 50%, correlate with the significant decline in the combustion of fossil fuels during the pandemic, primary in mobile sources. Similar reductions where observed in China when it cracked down on combustion sources in advance of the 2008 Olympics. This data provides a glimpse into what might be achieved if the United States were to adopt more aggressive policies encouraging alternative fueled vehicles and expanded renewable energy generation. However, the dire financial impacts associated with these reductions must also be considered as we contemplate the implications of the emission data gathered during this unusual situation.