Light-duty vehicle CO2 targets consistent with 450 ppm CO2 stabilization

Area of Science:

• Environmental science
• Automotive engineering
• Climate change mitigation

Background:

• Stabilizing atmospheric CO2 concentrations is critical for mitigating climate change.
• The light-duty vehicle (LDV) sector is a significant contributor to global CO2 emissions.
• Understanding emission reduction pathways is essential for policy development.

Purpose of the Study:

• To analyze CO2 emission reductions from the LDV fleet needed for atmospheric CO2 stabilization at 450 ppm.
• To define CO2 glide paths (g CO2/km targets) for average new LDVs from 2010 to 2050.
• To assess the consistency of existing and proposed regulations with these CO2 glide paths.

Main Methods:

• Global analysis of CO2 emission reduction scenarios for LDVs.
• Development of CO2 glide paths based on stabilization targets.
• Accounting for fleet growth, driving patterns, biofuel availability, and fuel composition.
• Comparison of LDV regulations in the U.S., EU, China, and Brazil with defined glide paths.

Main Results:

• Existing regulations in the U.S. (through 2025) and EU (through 2020) are broadly consistent with the CO2 glide paths.
• The defined CO2 glide path aligns with the upper end of the discussed 2025 EU range (68-78 g CO2/km).
• China's proposed 2020 regulation is more stringent than the glide path, while Brazil's 2017 regulation is less stringent.

Conclusions:

• Current LDV regulations through 2025 generally support the goal of stabilizing CO2 at approximately 450 ppm.
• The CO2 glide paths offer essential long-term direction for LDV powertrain and fuel innovation.
• Further policy alignment may be needed, particularly in regions with less stringent regulations, to meet global climate targets.