The researchers ran thousands of computer simulations on the steps needed to decarbonize passenger and freight travel, which make up the largest contributor to greenhouse gases. While they advised that “no single technology, policy, or behavioral change” is enough by itself to reach the target, eliminating tailpipe emissions would be a major factor.
There are reasons to be optimistic and several remaining areas to explore. In the scientific community, there is a lot of agreement around what needs to happen to slash transportation-related greenhouse gas emissions, especially when it comes to electrification. But there is high uncertainty for future transportation emissions and electricity needs, and this unique analysis helps shed light on the conditions that drive these uncertainties.
—Chris Hoehne, a mobility systems research scientist at NREL and lead author
The researchers analyzed in detail 50 deep decarbonization scenarios, showing that rapid adoption of ZEVs is essential alongside a simultaneous transition to a clean electric grid. Equally important is managing travel demand growth, which would reduce the amount of clean electricity supply needed.
The researchers found the most dynamic variable in reducing total transportation-related emissions are measures to support the transition to ZEVs.
Using a model called Transportation Energy & Mobility Pathway Options (TEMPO), the researchers performed more than 2,000 simulations to determine what will be needed to decarbonize passenger and freight travel. The study explores changes in technology, behavior, and policies to envision how passenger and freight systems can successfully transition to a sustainable future.
Policy changes may require new regulations that drive the adoption of electric vehicles, for example. Technology solutions will call for continued advancements in batteries, fuel cells, and sustainable biofuels, among others.
Behavior comes into play in considering shifts in population and travel needs. Someone moving away from an urban core, for example, might have to travel longer distances to work.
By employing a combination of strategies, the study shows that the maximum potential for 2050 decarbonization across the simulated scenarios is an 89% reduction in greenhouse gases relative to 2019, equivalent to an 85% reduction from the 2005 baseline.
Funding was provided by the US Department of Energy Office of Energy Efficiency and Renewable Energy Strategic Analysis Team.
