The climate/transport link transits directly via the energy sector. Conceptually the relationships are very simple. Reality is of course quite another thing.
Our immediate emergency target (climate change, resource depletion, and species extinctions) is to find ways to combine technologies and procedures which will allow us to virtually eliminate carbon-based fuels and impacts in a necessary short amount of time.
There are two main paths for achieving this:
Energy Efficiency Improvements:
The most immediate target is to find ways to attack the incredibly inefficient use of the present technology/operations mix in the mobility sector, which according to authoritative estimates runs ca. 10% and less of the BTU potential of the energy source. In the case of the energy efficiency of automobiles powered by internal combustion engines, an extreme case, we’re looking at efficiency rates relative to the actual delivered cargo (human or other) of less than 1%. This is the challenge within which innovators are already working and making substantial progress.
There is a long and varied chain of ways in which new technologies and procedures can be combined to achieve massive energy reductions, without compromising efficient mobility or the economy, many of them near-term and often of low cost. The key areas of opportunity include all of the current capture forms (solar, wind, hydro, geothermal, etc.), as well as fast-developing techniques for electricity storage.
Essentially we are looking out to an electricity driven mobility system, with highly efficient energy use on the one hand, accompanied by a massive shift to renewables.
The second energy vector is the potential for near-term shifts in the availability and price of renewables. Progress in these various areas is extremely impressive in the last several years, with signs for even faster rates of growth. 
In this author’s view, the bottom line for all those concerned in the transport sector is to become more active and insistent in support of public funding and encouragement of R&D, both to clarify the best path for achieving energy efficiency improvements, and even more important, to accelerate the shift away from fossil fuels.
Political willingness to embrace demonstration and advanced projects will play a critical role in accelerating the penetration of this shift. The transport sector should be at the vital core of the solution.
Convergence: Toward a General Theory of Transport in Cities:
The following is one of a set of short working summaries intended for full presentation and discussion in a cycle of international peer conferences and workshops, with a view to inviting critical comment and feedback on the principal ideas and arguments set out in support of a book in progress under the title: Convergence: Toward a General Theory of Transport in Cities. A future version of this essay is to appear in expanded final form as a chapter in the opening section of the book. We enthusiastically invite reader comment and critical views.
 I have long been very critical about knee-jerk government support for electric vehicle projects, on the understanding that technology selection and development is something best carried out by the private sector, whereas the goal of government policy should be to provide broad guidelines and specific performance parameters and targets, leaving it to the competence of the private sector to decide what in their expert view is the technology package that will do this job best. Then, I reasoned, they will put the investments needed to make their technology choice competitive. However my position on this has over the last year evolved considerably, as hopefully the above will start to make clear.
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Bio: Educated as an international development economist, Eric Britton is an American political scientist, teacher and sustainability activist who has worked on missions and advisory assignments on all continents. Professor of Sustainable Development, Economy and Democracy at the Institut Supérieur de Gestion (Paris), he is also MD of EcoPlan Association, an independent advisory network providing strategic counsel for government and business on policy and decision issues involving complex systems, social-technical change, civil society and sustainable development. Founding editor of World Streets: The Politics of Transport in Cities | See Britton online at https://goo.gl/9CJXTh and @ericbritton