Characterizing urban anthropogenic fossil fuel CO2 emissions before and after COVID-19 pandemic

Reducing anthropogenic greenhouse gases are an urgent requirement to combat dangerous climate change. Cities are major contributors of anthropogenic emissions, accounting for roughly 70% of emissions globally. An accurate estimate of urban emissions is necessary to guide climate action planning. Here, we present an ongoing effort in developing a high temporal-spatial resolution urban fossil fuel CO₂ (FFCO₂) emissions product from the Hestia project. Emissions from the state of Arizona, USA, are characterized at the road segment and building level from 2017 to 2021 for eight different emission sectors. Electricity production and onroad activity account for 80% of Arizona’s annual total CO₂ emissions during the analysis period. Emissions from electricity production have been declining partly due to the closure of a large coal-fired powerplant in 2019, and this increased the share of the emissions allocated to onroad activity. While most sectors saw a decline in emissions of -3% to -26% in 2020 due to the COVID-19 pandemic, the emissions increased in the industrial (+2%) and cement production (+16%) sectors. A substantial reduction was seen in the total transportation sector which included sharp declines in aircraft emissions activity. Focusing on three major cities in the state, we will explore and present an analysis of the emission peaks and hotspots across sectors and investigate how COVID-19 has impacted the spatial emission patterns. These results will be further analyzed with socio-economic indicators to help understand and narrow down areas that may be good targets for emissions reduction efforts.