Health and climate impacts of future United States land freight modelled with global-to-urban models

Driven by economic growth, globalization and e-commerce, freight per capita in the United States has been consistently increasing in recent decades. Projecting to 2050, we explore the emissions, and health and climate impacts of US freight truck and rail transport under various policy scenarios. We predict that, overall, air pollutant emissions and health impacts from the freight-truck-rail system will be greatly reduced from 2010 to 2030, while long-term climate forcing will continue to increase if petroleum is the fuel source. A carbon tax could shift freight shipments from trucking to energy-efficient rail, providing the greatest reduction in long-term forcing among all policies (24%), whereas a policy enforcing truck fleet maintenance would cause the largest reduction in air pollutant emissions, offering the largest reduction in mortalities (36%). Increasing urban compactness could reduce freight activity but increase population exposure per unit emission, offering slight health benefits over the current urban sprawl trend (13%).