Household carbon inequality in the U.S.

Abstract

Household carbon emissions are mainly affected by income and other key demographic factors. Understanding the contribution of these factors can inform climate responsibilities and potential demand-side climate mitigation strategies. By linking US consumer expenditure survey data with a nested national within a global multi-regional input-output model, this study estimates consumption-based GHG emissions for 9 income groups and assesses the carbon inequality in the US for 2015. Our results show that the per capita carbon footprint (CF) of the highest income group (>200 thousand USD per year) with 32.3 tons is about 2.6 times the per capita CF of the lowest income group (<15 thousand USD) with 12.3 tons. This is due to large gap in consumption volume and associated carbon emissions along the entire global production chain. Consumption pattern tends to narrow the gap in household per capita CF between income groups due to the lower carbon intensity per dollar spent by higher income groups. Another important factor influencing carbon footprints is household size and thus sharing of household equipment and other consumption items. The US average per capita CF is 18.1 tons compared to the global average of approximately 5 tons. The high carbon footprint across income groups in the US is largely due to the large contribution of emissions from heating and cooling and private transport, which reflects the settlement structure and lifestyles in the US, relying heavily on cars and living in larger houses.