Globalization of the world’s economy requires that humans and their goods move long distances. Consequently, passenger and freight travel are likely to double during the next half century. This expanded travel derives both from human population growth and from everyone traveling a greater distance each year. In addition, more people possess their own light-duty vehicle (passenger car or small truck) and are using them for travel.
Petroleum serves as the energy source for over 95% of transportation. The transportation sector consumes half of the world’s petroleum output, a proportion that is likely to increase in the future. A straightforward strategy for prolonging petroleum supplies is to invoke additional conservation measures in the transportation sector.
The Middle East supplies most of the world’s petroleum and has the world’s largest proved oil and natural gas reserves (i.e., reserves that have a reasonable certainty of being extracted). For this reason, among others, the political volatility of this region has global consequences. In October 1973, when the Yom Kippur War erupted between Israel and its Arab neighbors, Arab petroleum exporters initiated an oil embargo against Israel’s supporters including the United States, Western Europe, and Japan that they maintained until March 1974. Supplies of petroleum dropped, prices shot up, and motorists in these countries had to wait in long lines at filling stations. Five years after this embargo ended, the Iranian Revolution precipitated another oil crisis that again doubled petroleum prices and generated long lines at filling stations. Wars in Iraq from 1990 to 1991 and from 2003 to 2009 have also influenced oil supplies and prices. Conservation in the transportation sector would provide greater independence from Middle East oil supplies.
Conservation measures in the transportation sector also would reduce greenhouse gas emissions. About 21% of global emissions currently derive from transportation (33% in the United States; 10% in China), and this fraction is expected to reach 23% by 2030.  Emissions from all modes of transportation except buses are climbing at about 2% per year. Light-duty vehicles (passenger cars and small trucks) contribute the largest share of emissions; therefore, an obvious strategy for greenhouse gas abatement is to improve the fuel efficiency of light duty vehicles, to increase the availability and appeal of public transportation, and to introduce alternative fuels that result in lower emissions.
 International Energy Agency (2004b) World Energy Outlook 2004, Organisation for Economic Cooperation and Development, Paris, http://www.iea.org//textbase/nppdf/free/2004/weo2004.pdf .
This is an excerpt from the book Global Climate Change: Convergence of Disciplines by Dr. Arnold J. Bloom and taken from UCVerse of the University of California.
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