  The social cost of carbon (SCC) serves as a concise gauge of climate change's
economic impact, often reported at the global and country level. SCC values are
disproportionately high for less-developed, populous countries. Assessing the
contributions of urban and non-urban areas to the SCC can provide additional
insights for climate policy. Cities are essential for defining global
emissions, influencing warming levels and associated damages. High exposure and
concurrent socioenvironmental problems exacerbate climate change risks in
cities. Using a spatially explicit integrated assessment model, the SCC is
estimated at USD$137-USD$579/tCO2, rising to USD$262-USD$1,075/tCO2 when
including urban heat island (UHI) warming. Urban SCC dominates, with both urban
exposure and the UHI contributing significantly. A permanent 1% reduction of
the UHI in urban areas yields net present benefits of USD$484-USD$1,562 per
urban dweller. Global cities have significant leverage and incentives for a
swift transition to a low-carbon economy, and for reducing local warming.
