Expanding public transportation, walking, and biking in cities could save more than $100 trillion in public and private spending between now and 2050.
A new report shows that this shift also would result in reductions in carbon dioxide emissions reaching 1,700 megatons a year in 2050.
If governments require the strongest vehicle pollution controls and ultralow-sulfur fuels, 1.4 million early deaths associated with exposure to vehicle tailpipe emissions could be avoided each year, according to a related analysis by the International Council on Clean Transportation included in the report.
Doubling motor vehicle fuel economy could reduce CO2 emissions by an additional 700 megatons in 2050.
“The study shows that getting away from car-centric development, especially in rapidly developing economies, will cut urban CO2 dramatically and also reduce costs,” says report coauthor Lew Fulton, co-director of NextSTEPS Program at the University of California, Davis Institute of Transportation Studies.
“It is also critical to reduce the energy use and carbon emissions of all vehicles.”
The report is the first study to examine how major changes in transportation investments worldwide would affect urban passenger transport emissions as well as the mobility of different income groups. The findings should help support wider agreement on climate policy, where cleanup costs and equity between rich and poor countries are key issues.
The report is available in advance of September 23 United Nations Secretary-General’s Climate Summit, where many nations and corporations will announce voluntary commitments to reduce greenhouse gas emissions, including new efforts focused on sustainable transportation.
“Transportation, driven by rapid growth in car use, has been the fastest growing source of CO2 in the world,” says Michael Replogle, coauthor of the study and managing director for policy at ITDP, a global New York-based nonprofit.
“An affordable but largely overlooked way to cut that pollution is to give people clean options to use public transportation, walking, and cycling. This expands mobility options, especially for the poor, and curbs air pollution from traffic.”
The authors calculated CO2 emissions and costs from 2015 to 2050 under a business-as-usual scenario and a “High Shift” scenario where governments significantly increase investments in rail and clean bus transportation, and provide infrastructure to ensure safe walking, bicycling, and other active forms of transportation.
It also includes moving investments away from road construction, parking garages, and other steps that encourage car ownership, freeing up resources for the needed investments.
Cities around the world
Transportation in urban areas accounted for about 2,300 megatons of CO2 in 2010, almost one quarter of carbon emissions from the transportation sector. Rapid urbanization—especially in fast developing countries like China and India—will cause these emissions to double by 2050 in the business-as-usual scenario. Among the countries examined in the study, three stand out:
Currently the world leader in urban passenger transportation CO2 emissions, the US is projected to lower these emissions from 670 megatons annually to 560 megatons by 2050 because of slowing travel growth combined with sharp improvements in fuel efficiencies.
But a high shift to more sustainable transportation options, along with fewer and shorter car trips related to communication technologies substituting for transportation, could further drop those emissions to about 280 megatons.
CO2 emissions from transportation are expected to mushroom from 190 megatons annually to more than 1,100 megatons, due in large part to the explosive growth of China’s urban areas, the growing wealth of Chinese consumers, and their dependence on automobiles.
But this increase can be slashed to 650 megatons under the High Shift scenario, in which cities develop extensive clean bus and metro systems. The latest data show China is already sharply increasing investments in public transport.
CO2 emissions are projected to leap from about 70 megatons today to 540 megatons by 2050, also because of growing wealth and urban populations. But this increase can be moderated to only 350 megatons under the High Shift scenario by addressing crucial deficiencies in India’s public transport.
Under the High Shift scenario, mass transit access worldwide is projected to more than triple for the lowest income groups and more than double for the second lowest groups. This would provide the poor with better access to employment and services that can improve their livelihoods.
The Ford Foundation, ClimateWorks Foundation, and Hewlett Foundation supported the work.
Source: UC Davis