Long has there be talk about all sorts of geoengineering options to "save the world". Some of them are practical but can produce only minimal effects, such as making rooftops more reflective or most simply, to plant more trees (yes tree planting is an option of geoengineering, and it produces way more than minimal effects). Some of such options, such as ejecting aerosol into stratosphere, or to make oceans photosynthesize using microbes, are still at the stage of drawing board and largely controversial (Shepherd, 2012; Heutel et al., 2016). What about transportation then? Are there geoengineering options to make roads and railways self-account for their externalities?

Well, I know this sounds a bit over-simplified, but what about making roads greener than they  are right now? Residents in large urban areas may already be witnessing lovely flower or small bushes planted along lifted roads, or simply the trees planted alongside roads that we see everyday. Although “green” transportation engineering and geoengineering is often associated with a certain degree of futurism or experimental technology, it provides one alternative path along which climate tipping points may be avoided and society renewed (somehow). As a proposed solution, with fully autonomous vehicles, especially freight vehicles that can operate in fleets that greatly reduce risk of accidents and congestion, large proportions of road pavement can be replaced with certain kinds of greenspace that can be stowed away if more pavement surface is needed (Luo, 2019). Other propositions may not go as far fetched, but the overall aim after all should be to make transportation infrastructure accounts for its own externalities. Above all, many such projects require one essential prerequisite, that is real time and intelligent central coordination of all transportation resources. To this end, “green” infrastructure should be woven with “smart” infrastructure (Jiang, 2015).

Geoengineering sometimes sounds a bit scary because of the risk of unexpected consequences, but what if small cubes containing photosynthetic microbes are interwoven with the pavement or asphalt so that road surface can become carbon sink? Or what about making asphalt more permeable so that there will be less polluted run-off? My point here is not all about selling these geoengineering options, but to note one thing: geoengineering does not need to be so sci-fi like, even planting a tree is geoengineering.

References

Heutel, G., Moreno-Cruz, J., & Shayegh, S. (2016). Climate tipping points and solar geoengineering. Journal of Economic Behavior & Organization, 132, 19–45. https://doi.org/10.1016/j.jebo.2016.07.002

Jiang, L. (2015). Smart City, Smart Transportation: Recommendations of the Logistics Platform Construction. In 2015 International Conference on Intelligent Transportation, Big Data and Smart City (pp. 729–732). https://doi.org/10.1109/ICITBS.2015.184

Luo, Y. (2019). FROM TRANSPORTATION INFRASTRUCTURE TO GREEN INFRASTRUCTURE — ADAPTABLE FUTURE ROADS IN AUTONOMOUS URBANISM. Landscape Architecture Frontiers, 7(2), 92–99. https://doi.org/10.15302/J-LAF-20190209

Shepherd, J. G. (2012). Geoengineering the climate: an overview and update. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 370(1974), 4166–4175. https://doi.org/10.1098/rsta.2012.0186