Near-Real-Time Estimates of Daily Fossil-Fuel CO2 Emissions from Cities Worldwide
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Cities are at the frontline of tackling climate change as over half of the global fossil-fuel carbon dioxide (CO2) emissions are generated from cities. High temporal resolution urban emission inventories are critical for local climate policymaking and agile mitigation progress monitoring. Unfortunately, such datasets are still lacking for most cities, and existing inventories are mostly at national scale and often lag reality by at least one year. City self-reported inventories also suffer from low reliability due to the lack of peer review. In this study, we present and analyze the latest version of Carbon Monitor Cities, a near-real-time fossil fuel emissions dataset that provides daily, city-level estimates of scope-1 CO2 emissions from January 2019 through March 2022 for over 1500 major cities worldwide, including the first estimates for many cities in low-income countries. This dataset is developed based on a globally harmonized workflow that covers five sectors: power, residential, industry, ground transportation, and aviation, which account for over 70% of total emissions from a city. Carbon Monitor Cities builds on the latest methodological frameworks for estimating near-real-time daily CO2 emissions which have been successfully used for revealing the impacts of COVID-19 on global emissions. We find that for most cities, emissions exhibited a significant drop in spring 2020 due to the COVID-19 pandemic, and rebounded in 2021. We also highlight the different sectoral responses to lockdowns and daily emission patterns that reveal a city’s geographic and socio-economic characteristics. We expect this high temporal resolution city-level emissions dataset to play a significant role in future climate change-related research and policymaking.