The Paris Climate Agreement, approved by world leaders last December, represented a bold commitment to prevent the worst impacts of global warming - a commitment that must now be followed by action.
Meeting the agreement's target of limiting global warming to no more than 2° C (and ideally no more than 1.5° C) above pre-industrial levels will require the United States to reduce its emissions of greenhouse gases by more than 80 percent, and possibly as much as 100 percent, by 2050.
That is 34 years from now. And the clock is ticking.
Can it be done? In March, we joined with Environment America Research & Policy Center to produce We Have the Power, a report that argued that it is possible to repower America with 100 percent renewable energy. And at the end of May, we will release A New Way Forward: Envisioning a Transportation System without Carbon Pollution, which makes the case that America has the tools and strategies it needs to eliminate carbon pollution from urban, light-duty transportation by 2050.
The report explores scenarios by which U.S. metropolitan areas might reduce energy demand for light-duty travel by as much as 90 percent - making it possible to repower our transportation system with clean renewable energy at the same time we eliminate carbon pollution from other areas of the economy.
Ours will not be the first analysis to suggest that decarbonizing transportation is possible. Over the last several years, government agencies, academics, environmental advocates and others have explored a variety of pathways (warning: PDFs) by which we can move toward a zero-carbon transportation system.
And new pathways are opening all the time. The spectacular growth of shared mobility platforms, rapid advances in information technology, recent trends toward urbanization, the mass commercialization of electric vehicles, and the impending advent of autonomous vehicles create new opportunities to rethink how people and goods move through and around our metropolitan areas - and to fix many of the sources of inefficiency and waste that cause America's transportation system to be so exceptionally polluting, as well as so exceptionally expensive and dangerous.
Let's waste no time confronting the elephant in the room: It is possible to believe that decarbonizing transportation is technically possible, and even beneficial, but at the same time be skeptical about the ability of our political system to achieve the goal. In our conversations with people working for sustainable transportation around the country this year, nearly everyone complained in some way about "the politics" in their communities, which are perceived as a hard constraint on the ability to move forward with sensible transportation policies.
And so, while we need to talk about the technical capacity of various technologies, services and policies to reduce greenhouse gas emissions from transportation, we need to spend just as much, if not more, time discussing ways to overcome the cultural, political and institutional barriers that so often limit our vision of what is possible.
The good news is that history is filled with examples of major transformations in society, politics and technology that occurred more rapidly than anyone thought possible. The task of transportation and climate advocates in these next few years is to identify and work to achieve the contemporaneous and mutually reinforcing shifts in public policy, economics, technology and culture that can make the seemingly improbable changes that must happen in our transportation system over the next several decades a reality.