Climate 2030

The document analyzes the U.S. transportation sector's contribution to global warming, noting it is the second-largest source of emissions, primarily driven by light-duty vehicles. It proposes a three-pronged approach: improving vehicle and air conditioning efficiency, transitioning to low-carbon fuels (such as cellulosic biofuels, electricity, and hydrogen), and reducing vehicle miles traveled (VMT) through smart growth and transit expansion. The report details specific fuel economy targets for 2020 and 2030 and advocates for performance-based emission standards over traditional fuel economy standards to better account for non-CO2 emissions and alternative fuels.

• The U.S. transportation system is the second-largest contributor to national global warming emissions, trailing only power plants. It produces approximately 30 percent of total emissions and 36 percent of all carbon dioxide emissions, with the sector relying on petroleum for 98 percent of its fuel.
• Light-duty vehicles are the primary source of transportation emissions, accounting for over 60 percent of the total and about 20 percent of the entire nation's emissions. Medium- and heavy-duty vehicles follow at 18 percent, and aircraft at 10 percent.
• Existing 'off-the-shelf' technologies could increase the fuel economy of new cars and light trucks to 38 mpg, while the addition of hybrid-electric technology could push the fleet average to over 50 mpg.
• Vehicle air conditioning systems contribute significantly to global warming because current refrigerants have a heat-trapping impact more than 1,400 times that of carbon dioxide. Replacing these with alternatives like HFC-152a or HFO-1234yf could reduce emissions by approximately 8 grams per mile.
• Heavy-duty truck efficiency could be improved by about 60 percent through better engines, transmissions, aerodynamics, and tires, potentially raising fuel economy from 6 mpg to over 9.5 mpg and reducing emissions per truck by more than 36 percent.
• The report argues that the EPA should regulate carbon emissions directly rather than relying on NHTSA's CAFE standards. EPA regulation would allow for longer-term standards, the inclusion of non-CO2 emissions (like refrigerants), and a more accurate accounting of the carbon benefits of alternative fuels.
• Cellulosic biofuels, derived from plant waste and grasses, have the potential to cut carbon emissions by 80 percent or more compared to gasoline. The U.S. could potentially produce 30 billion gallons of these low-carbon biofuels by 2030, displacing 20 billion gallons of gasoline.
• Plug-in hybrid vehicles with an all-electric range of 30 miles could reduce carbon emissions by about 55 percent compared to current vehicles, increasing to at least 70 percent if the electricity is sourced from a 2030 grid with 70–80 percent lower carbon emissions.
• To reduce vehicle miles traveled (VMT), the report suggests smart-growth policies, such as compact development, which could reduce VMT by up to 30 percent. Other measures include pay-as-you-drive insurance, which could reduce national VMT by more than 7 percent.
• Shifting freight from trucks to rail is highly efficient, as trucks emit two to three times more carbon than trains for similar loads. Shifting 2.5 percent of truck freight to rail by 2030 could reduce emissions from those shipments by half or more.

APA

Union of Concerned Scientists (n.d.). Climate 2030. https://www.ucs.org/sites/default/files/2019-09/climate-2030-roadmap-chapter.pdf

Chicago

Union of Concerned Scientists. Climate 2030. n.d. https://www.ucs.org/sites/default/files/2019-09/climate-2030-roadmap-chapter.pdf.

Wikipedia

{{cite report |author=Union of Concerned Scientists |title=Climate 2030 |url=https://www.ucs.org/sites/default/files/2019-09/climate-2030-roadmap-chapter.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{unionofconcernedscientistsndclimate, author = {{Union of Concerned Scientists}}, title = {{Climate 2030}}, institution = {Union of Concerned Scientists}, url = {https://www.ucs.org/sites/default/files/2019-09/climate-2030-roadmap-chapter.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }