Effects of recent energy system changes on CO2 projections for the United States

• Published in: Clean technologies and environmental policy Vol. 19; no. 9; pp. 2277 - 2290
• Main Authors: Lenox, Carol S., Loughlin, Daniel H.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2017; Springer Nature B.V
• Subjects: Air quality; Air quality standards; Biomass energy; Building codes; Carbon dioxide; Carbon dioxide emissions; Earth and Environmental Science; Effects; Efficiency; Electricity consumption; Energy consumption; Energy efficiency; Energy policy; Environment; Environmental Economics; Environmental Engineering/Biotechnology; Environmental policy; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Innovations; Original Paper; Regulation; Regulations; Smart growth; Sustainable Development; Technological change; Urban planning; United States > US; Energy system; Energy modeling; Carbon dioxide; Emission projections
• ISSN: 1618-954X; 1618-9558
• DOI: 10.1007/s10098-017-1417-y

Recent projections of future US carbon dioxide (CO 2 ) emissions are considerably lower than projections made just a decade ago. A myriad of factors have contributed to lower forecasts, including reductions in end-use energy service demands, improvements in energy efficiency, and technological innovations. Policies that have encouraged these changes include renewable portfolio standards, corporate vehicle efficiency standards, smart growth initiatives, revisions to building codes, and air and climate regulations. Understanding the effects of these and other factors can be advantageous as society evaluates opportunities for achieving additional CO 2 reductions. Energy system models provide a means to develop such insights. In this analysis, the MARKet ALlocation (MARKAL) model was applied to estimate the relative effects of various energy system changes that have happened since the year 2005 on CO 2 projections for the year 2025. The results indicate that transformations in the transportation and buildings sectors have played major roles in lowering projections. Particularly influential changes include improved vehicle efficiencies, reductions in projected travel demand, reductions in miscellaneous commercial electricity loads, and higher efficiency lighting. Electric sector changes have also contributed significantly to the lowered forecasts, driven by demand reductions, renewable portfolio standards, and air quality regulations.