Carbon monoxide (CO), nitrogen oxides (NOx)
Our team have been measuring greenhouse gas and air quality concentrations at the rooftop observatory at the Advanced Science Research Center (ASRC) located on the City University of New York (CUNY) campus in Harlem, Manhattan since 2019. We have observed changes in atmospheric composition associated with atmosphere-surface exchange of greenhouse gases and related air pollutants throughout the New York City Metropolitan area. COVID lockdowns reduced NOx (Tzortziou et al., 2022) and CO (Schiferl et al., 2024) by less than expected, indicating that stationary combustion is an under-appreciated source of both pollutants.
On a tall tower in the suburbs of NYC, we joined the FROG-NY and FROGsicle projects of PIs Delphine Farmer (Colorado State University) and Dylan Millet (University of Minnesota) to understand air pollutants in Summer 2023 and Winter 2024. We continue to analyze this data.
Volatile Organic Compounds (VOCs)
NYC is one of the few remaining NOx-saturated cities in the US, with substantial ozone titration in the city core. Ozone production can still be sensitive to emissions of VOCs. Urban greening plans, while commendable for quality of life in the city, should prioritize species that do not emit isoprene to minimize the increase in ozone concentrations (Wei et al., 2024). Especially as future warming temperatures may increase emissions of VOCs and undermine VOC reduction policies (Cao et al., 2023).
On a tall tower in the suburbs of NYC, Franklin et al., 2025 identified wildfire smoke, biogenic emissions, heat, and emerging anthropogenic emissions as critical global change vulnerabilities for North American urban aerosol pollution that pose unique challenges for control strategies.
Indoor Air Quality
Indoor air quality is crucial for public health in cities. As we work to improve the energy efficiency of buildings, we need to ensure clean air ventilation is also improved - especially for buildings that allow combustion indoors. The combustion of any fuel will produce NOx and carcinogens like benzene have been found in areas with natural gas stoves. We worked with WeACT, a wonderful environmental justice group based in Harlem, to measure NOx pollution in kitchens with natural gas and induction stoves (Daouda et al., 2024). We found that adopting induction stoves in public housing dramatically improves air quality. This study contributed to the decision by New York State and City to purchase 10,000 induction stoves for NYCHA housing.
Climate Justice versus Environmental Justice
Commane and Schiferl, 2022 argued that climate mitigation policies for cities must consider air quality impacts of these actions. Commane, 2026 (book chapter in Climate Justice Now!) discussed how climate and environmental justice are not automatically complementary but they can be with careful implementation.
Nature-based climate solutions like urban greening and tree planting should consider the species of tree selected. They should select tree species that do not emit isoprene to minimize an increase in ozone concentrations (Wei et al., 2024).