Unequal household carbon footprints in the peak-and-decline pattern of U.S. greenhouse gas emissions

Abstract

Greenhouse gas (GHG) emissions in the U.S. peaked and declined in the first decade of the 21st century, largely attributed to the increased use of natural gas and renewable energy replacing coal. However, if and to what extent household consumption also played a role in this trend is still debated. Finding demand-side options is necessary to hedge against the risks of technology solutions failing to materialize. To fill this gap, this study analyzes the change in GHG emissions driven by U.S. household consumption, explores the drivers of this change and the contribution of different income groups. To this end, this study combined the U.S. consumer expenditure survey with an environmentally-extended multi-regional input-output framework to analyze changes in GHG emissions induced by household consumption between 2001 and 2015. This study further analyzed how much population, consumption volume and consumption patterns drove emission changes by quintile income groups. The results show that changes in household consumption contributed approximately one-third of the national emission decline. The decline in GHG emissions from U.S. households was mainly associated with a decrease in the consumption of carbon-intensive products, including gasoline, electricity, and animal-based food products. The top quintile income households were the main contributors to the emission increase before the peak, while the third and fourth income quintiles became emission mitigation leaders after 2010. Carbon inequality increased during the 2001–2006 period, mainly driven by increased wealth and consumption of high-income households, and was relatively stable after the peak. Emissions from certain consumption categories of the top quintile group are significantly higher than the bottom four quintiles with increasing trends, especially leisure-related services and goods, which require more attention in future policymaking for emission reduction.