Fossil CO2 emissions from warehouse and distribution centers in southern California’s inland empire

The rise of e-commerce has led to a rapid expansion of warehouses and distribution centers (W&DCs). However, impacts of e-commerce logistics, including emissions of fossil fuel-derived carbon dioxide (ffCO2) on urban greenhouse gas inventories, remain poorly quantified. Here, we developed a 40-year tree-ring radiocarbon (14C) record to isolate ffCO2enhancements within a W&DC cluster and in the urban background of Southern California’s Inland Empire, a region of concentrated W&DC growth during this period.