Greener Transport Mitigates Climate Change

Article excerpt

The emission of greenhouse gasses is considered by most scientists to be a major cause of observed climate change. According to the U.S. Department of Transportation (DOT), 28 percent of all GHG emissions in the United States came from transportation uses in 2006, 97 percent of which was from the combustion of fossil fuels. Creation of the fuel and the manufacturing of the vehicles add additional GHGs to the "life cycle" calculations for transportation.

According to DOT, passenger cars and small trucks created 63 percent of the transportation-related GHG emission in the United States in 2006, while air transportation represented 9 percent, and buses and rail constituted less than 2 percent of the total. Several strategies are available to lessen this impact on the global environment, but a variety of political and economic barriers exist, as well as a lack of public support for climate change adaptation overall.

Summer 2010 saw an unprecedented heat wave on the East Coast that affected transportation. In Washington, D.C., a train was stopped just minutes out of the station by heat-warped rails and heat-damaged overhead electrical lines, trapping passengers for more than four hours. So while transportation was a victim of climate change in this instance, it is often cited as a potential contributor to climate change mitigation as well.

The Transportation Research Board (TRB) sponsored a study of climate change and its potential impact on transportation. Recognizing that not enough is known about every facet of climate change to make firm predictions, the study none the less pointed out critical areas for adaptation in the transportation domain. TRB notes that capital improvements in transportation systems should consider long-range climate change impacts, such as sea-level rise and increased heat and drought.

Climate change and its related hurricanes and storms also bring transportation into the emergency response arena as an evacuation asset, which requires special consideration when designing roadways or track bed routes. Technology should be applied to monitor and warn about the potential effects of flooding, wave action, winds, and temperatures that exceed the design standard for infrastructure.

Unpredictable climate change means that engineers must build resilience into transportation infrastructure to speed repairs and limit the loss of use of critical transportation assets. Drainage capacity challenged by bigger storms and changes in sea level may compromise existing culverts and storm drains.

Professor Steven Cohen of Columbia University's Earth Institute points to the need for improved--and resilient--transit services in congested cities. Only significant federal subsidies will enable cash-strapped transit agencies to be a partner in GHG emission mitigation through more attractive mass transit systems, and climate change adaptation through more resilient infrastructure. Cohen suggests that congestion pricing for cars in urban areas could generate both the funding and incentive for urban mass transit that could be a partner in climate change management.

Climate Change and Sustainability

Sustainability is garnering international attention. The GHG footprint and its reduction have prompted businesses, agencies, and individuals to proactively find ways to do their part to lessen such emissions and have a mitigating effect on global climate change. At the same time, a worldwide economic downturn has forced attention toward stimulating economies by investing in green development and new technologies. President Obama has said repeatedly that building a new energy economy is at the center of his plans to boost the economy and get people back to work.

But what is meant by sustainability, and how are immediate quality of life issues, such as economic downturns or dependency on fossil fuels, balanced against long-term sustainability efforts? Sustainability is derived in part from a concept that emerged in the 1980s called "sustainable development." One definition of sustainable development is that it meets the needs of the present without compromising the ability of future generations to meet their own needs. It is development that improves the standard of living and quality of life, while at the same time protecting and enhancing the natural environment and honoring local culture and history.

Climate Change Mitigation in Transportation

Transportation facilitates international commerce and contributes to climate change mitigation. Commercial freighters carry cargo around the world and use fossil fuels that create GHG emissions. As a result of rising fuel costs many freighters have adopted a "slow steaming" policy. Maersk North America reports that its ships used to sail at 21 knots, but now "slow steam" at 15 knots, for a savings of 45 metric tons of fuel for each 500 nautical miles, and a concomitant reduction in GHG emissions. A Dutch research firm noted that industry-wide changes in steaming speeds have resulted in a drop of some 30 percent in GHG emissions from the cargo shipping sector.

Clearly, transportation also is critical to urban living. In 2010 it was estimated that cities occupy 1 percent of the Earth's surface while holding 75 percent of its people. City living is marked by congestion, increased GHG emissions, more traffic accidents, and loss of productivity and efficiency.

In many communities, congestion problems are solved through the application of Intelligent Transportation Systems that incorporate wireless technology. For example, Siemens AG has created technology that incorporates a [CO sub 2] sensor. When GHG emissions rise, the systems control traffic signals to improve traffic flow and reduce related GHG emissions and may use electronic sign boards to reroute traffic around the congested areas.

Searching for parking in congested urban centers is another activity that generates congestion and extra GHG emissions. Siemens AG also has a sensor system that permits drivers to place a reservation for a parking space, and uses embedded sensors to monitor and report the location of vacant parking spaces . They estimate that searching for parking spaces results in 950,000 excess miles driven with 730 tons of GHG emissions, both of which could be reduced by the application of parking sensor technologies.

Sustainable Transportation in California

Sustainable transportation is not a new idea. However, because it is directly linked to GHG emissions and carbon dioxide levels, it is an area of great concern. The transportation sector is the biggest contributor to statewide greenhouse gas emissions in California, representing roughly 38 percent of the total GHG emissions that are linked to global climate change.

Santa Clara County and the VTA

The mass transit system in Santa Clara County, California, is managed by the Valley Transit Authority (VTA), a special purpose government that is both a transit provider and a multimodal transportation planning organization involved in the development and oversight of local transit, highways and roadways, bikeways, and pedestrian facilities. VTA's mission statement refers to improving the environment: "Implementing programs for the conservation of natural resources, the reduction of green house gases, the prevention of pollution, and the use of renewable energy and materials."

Historically, VTA has undertaken many projects that specifically address energy conservation. Past projects related to environmental stewardship included replacement of rooftop air conditioners with Energy Star rated equipment, installation of solar powered bus stops, construction of new water treatment plants at bus yards, installation of efficient roofing materials, and the operation of zero-emission buses.

In fact, providing public transportation itself is environmentally responsible and minimizes the long-term environmental effects of transportation by reducing the number of privately owned cars on the road. Continuing in its efforts to provide an environmentally responsive transit system, the VTA Board of Directors officially approved the Sustainability Program in 2008, signaling a commitment to a greener Santa Clara Valley.

Currently, VTA is going green. Its environmental programs and resource management and facilities maintenance departments are responsible for developing scope of projects or procurement processes that "meet today's needs without compromising future generations." Some of the other programs that VTA is implementing include

* use of fuel-efficient vehicles

* transit-oriented development that places high density housing near transit stops

* reduction of water use and hazardous waste production at its maintenance facilities

* energy saving improvements to VTA properties, such as the use of CFL and LED lighting.

The next step for the VTA is to develop a formal, detailed sustainability plan. VTA has developed a Secretariat Sustainability Management Plan (SSMP), approved by the VTA Administrative Committee in September 2008. VTA has devised strategies for adopting internal sustainability practices in its day-to-day working environment. For example, the SSMP states an objective of management systems is to "ensure that VTA's organization processes, purchases, use of equipment and materials, and disposal of goods are all reviewed and conducted within a sustainable framework."

Figure 1 | 2004 Emissions in California

38%  Transportation
6%   Agriculture
3%   Commercial
6%   Residential
20%  Industrial
12%  Electricity Generation (in state)
13%  Electricity Generation (imports)

Source: ARB, "California 1990 Greenhouse Gas Emissions Level and 2020
Emissions Limit" (2007);

Associated with that objective is the strategy to assess existing electrical appliances for energy efficiencies and budget for replacement to Energy Star efficient appliances. In this way, culture change occurs within the VTA organization as employees are asked to move from a mindset of unlimited resources to a sustainable set of priorities that work toward mitigation of climate change through limiting GHG emissions.

Alameda-Contra Costa Transit District

Alameda-Contra Costa Transit District (AC Transit) has also focused on sustainability. According to a 2009 AC Transit Environmental Sustainability Report, reduction of GHG emissions from large-scale transportation systems can be achieved along three basic domains:

1| reduction of the carbon intensity of fuels

2| improvement of vehicle efficiency (such as better gas mileage)

3| reduction of the overall vehicle distance traveled through more efficient routing, limiting time trapped in traffic and elimination of little used routes.

The AC Transit has a sustainable public transit program that was first implemented in 2007. The 2009 sustainability program includes a number of programs designed to reduce GHG emissions through more efficient use of rolling stock. In an effort to make use of mass transit more attractive than single passenger cars, AC Transit promotes the co-location of public transportation with transit-oriented residential developments.

AC Transit's Rapid Bus operates on dedicated lanes on specified routes, offering transit passes that reduce the cost of trips. It also employs the NextBus system, which allows passengers to get real-time information on bus arrivals through cell phones and the Internet.

Technological initiatives include Clean Fuels Test Program, including HyRoad, a hydrogen fuel cell created by Chevron. These HyRoad cells are used in zero emission buses and cars in the AC Transit fleet. Rooftop solar panels have been installed by SunPower to run the hydrogen fuel facility, representing a costfree, publicprivate partnership with a grant of $1.8 million from local energy utility PG&E and federal tax credits of 30 percent.

Chevron also has provided two other alternative fuels for testing in transit vehicles: biodiesel fuel and gas-to-liquid diesel, which are each expected to be more environmentally friendly than standard fossil fuels. In partnership with Van Hool, AC Transit is developing hybrid engines for neighborhood (30 foot) buses that use gasoline and nickel metal hydride batteries that capture energy from braking.

Estimating the Cost of Sustainability

Hard costs for implementation of the VTA sustainability policy were originally budgeted at Dollar2 billion during the FY2007 and $1 billion for FY2008, under VTA's non-Measure A Capital Improvement Program (CIP). This represented approximately 2.1 percent and 1.4 percent of the total capital program costs, respectively.

Current and potential revenue sources for the non-Measure A Capital Program include restricted revenues, such as various grants, and unrestricted revenues such as Federal Transit Formula Funds and Prop 1B Transportation Infrastructure Bond Act revenues. There are some soft costs that may be difficult to quantify, such as supporting sustainable, transit-oriented development along major transit corridors. It is difficult to associate costs with the value of VTA's influence over public land use and development.

In its infancy, the sustainability program has been economically beneficial. The use of public transit is one of the most effective actions to reduce GHG by individuals. The American Public Transportation Association has reported that if one solo commuter in a household gives up his daily driving, it will reduce the household carbon footprint by 10 percent. Giving up a second car for public transportation reduces a household's carbon emissions up to 30 percent.

By November 2008, the VTA had replaced 75 older paratransit and non-revenue, gas-powered vehicles with hybrids, resulting in a net reduction of annual GHG output by 385 tons. The fuel data confirmed an annual savings of 121,000 gallons per year, or approximately Dollar 485,000. If, on average, the hybrid vehicles cost Dollar 20,000 each, simple payback based on fuel use alone would occur in approximately three years.

Another example of sustainability is reduced water usage by 1.54 million gallons over a four-month period due to comprehensive water conservation improvements at 17 facilities. These improvements were developed with the support of the Santa Clara Valley Water District's Water Use Survey Program and Irrigation Technical Assistance Program. The savings is equivalent to the volume of 2.3 Olympic-sized swimming pools. Based on an average cost per gallon obtained from San Jose's Municipal Water Company, the annual savings ranged from Dollar 13,000 to Dollar 15,000.

Bottom Line

Transportation is linked to everything we do. In California alone, the transportation sector is the biggest contributor to GHG emissions, representing roughly 38 percent of the total emissions that cause global warming. To meet today's needs, VTA must develop goals and strategies for achieving sustainability. Public transportation is not inherently profitable, but linking transportation development with environmental benefits could help bridge the economic gap.

Sustainability is not a new concept. Nevertheless, many agencies fall short when attempting to apply this concept in a meaningful way to public transportation systems. AC Transit and VTA have each undertaken operational and technological methods for lessening greenhouse gas emissions and thereby mitigating climate change.


Alameda-Contra Costa Transit District, Environmental Sustainability Report, AC Transit for the Environment, February 2009.

Santa Clara Valley Transportation Authority, VTA Helps Keep the Valley Green! (0804-6294).

Sustainability Plan, Volume 1: Setting the Context, The Oregon Department of Transportation, September 2008.

VTA Secretariat Sustainability Management Plan 2008-2010, September 2008.

U.S. Department of Transportation. (2010) Transportation's Role in Climate Change.

Frances McCormack, P.E., was an engineer with the City of San Francisco, and a student in the Engineering Management program at San Jose State University. She passed away unexpectedly in May 2010. Frances L. Edwards, PbD, CEM, is the deputy director for the National Transportation Security Center of Excellence at the Mineta Transportation Institute, San Jose State University, and director of the master of public administration program. Contact her at