Transportation

Transportation is one of the largest economic sectors in the world, growing at a rate of 2.5% a year.  In addition to emitting 25% of the earth’s total greenhouse gas emissions, the transportation industry is responsible for air and water pollution.  The sector also consumes vast amounts of energy and natural resources for road, rail, and runway maintenance; vehicle construction; and fuel extraction and refinement

Aviation

Automobile_and_Trucking

Rail

Ocean_Transport

What_You_Can_Do

Aviation

Airplanes currently produce 3% of the earth’s total greenhouse gas emissions, which are three times the amount produce by automobiles. In addition to carbon dioxide and nitrogen oxide, airplanes emit water vapor that form condensation trails, or contrails in the upper atmosphere.  These contrails increase earth’s heat retention by. Airplane contrails also increase particulate matter, adding to ozone creation. In both passenger and freight transport, the aviation sector is expected to grow by 5% a year, while the current commercial airplane fleet is projected to double by 2025.

Trends in the Industry
In 2005, when Airbus 380, capable of seating up to 853 passengers, made its maiden flight, the trend in aviation was size; to simply “be bigger”. However, as the industry faces growing fuel costs and concern over global warming, fuel efficiency and alternative fuels become a priority.

Fuel Efficiency
A key component to increased fuel efficiency is lighter aircraft. Recently, the airline industry began constructing fuselage made from a blend of titanium, aluminum, and a composite of carbon fiber and reinforced plastic. Stronger and lighter than conventional aluminum, composite material will make up over half the fuselage of both Airbus 380 and Boeing 787. Designers expect the lighter material to boost fuel efficiency by 20%. Looking to reduce emissions by 50% in 2020, many airlines are researching lighter airframes, as well as altering engines.

On the Horizon - Alternative Fuels
The aviation industry is considering alternatives to conventional kerosene jet fuel. The fuel must be light to ensure fuel efficiency, and must be refined to handle high-performance engine specifications.  Some alternative fuels include:
- Natural Gas. Liquefied natural gas (LNG) blended with petrodiesel produces a fuel light and refined enough for jet engine use in unmodified jet engines. In addition to releasing less carbon, it contains no sulfur, benefiting local air quality.
- Synthetic fuel. Much like LNG, synfuel is a blend of liquefied fuel derived from oil shale, coal, natural gas, tar sands, waste plastics, or even biomass.,  It emits far less greenhouse gases.
- Biofuel. Early in 2008, Virgin Airlines completed its first test flight from London to Amsterdam on fuel derived from babassu (oil made from the babassu palmtree) and coconut oils. No modifications to the airplane were necessary.  Weight reduction and increased efficiency still remain key issues in aviation improvement . According to NASA, performance could be improved by using only small amounts (5 to 20%) of biofuel with regular jet fuel.
- Liquid Hydrogen. Emitting only water vapor, liquid hydrogen appears to be the cleanest source of alternative fuel. However, NASA notes that hydrogen’s heavy fuel tanks decrease fuel efficiency by 28% in short flights (500 miles), and 2% in longer flights (3,000 miles).

For more information on alternative fuels, visit Global Challenges – Energy.

Automobile and Trucking

Trucks and automobiles pollute the air with the following:

• Green house Gases
• Carbon monoxide
• Hydrocarbons
• Nitrogen oxide
• Carbon dioxide
• Smog and Ozone Ingredients
• Lead
• Particulate matter
• Volatile organic compounds (VOCs)

In the US, transportation accounts for 33% of greenhouse gas emissions, and will grow at an estimated 1.8% a year. Of that amount 60% comes from personal vehicles, while the remaining 40% comes from aviation, rail, ocean travel and commercial goods trucking. Though trucking emits less greenhouse gases, overall, it is more damaging to the climate, according to the UN. While the automobile and public transit industry have reduced impact and use of cars, little has changed for commercial trucking.

Changes in the Automobile Industry
To decrease greenhouse gas emissions, the automobile industry has begun the following changes:

• Scaling down the vehicle size
• Creating aerodynamic designs
• Building fully recyclable cars
• Designing cars to run on alternative fuel

Electric Cars
Also known as electric vehicles or EV’s, electric cars run on batteries rechargeable at home, at charging stations along roads and streets, or at parking lots and taxi stands. Outlets from high-powered electric grids, allow drivers to plug in for a minimal cost, and in some countries, for free. It takes up to 10 minutes to fully charge a vehicle. At home, drivers recharge from a standard outlet. Because of its low voltage, it may take between eight and 12 hours to fully charge a car. Special wiring increases voltage and decreases charge time. Electric cars generally use .17 to .37 kilowatt-hours per mile.

Batteries are the largest factor in energy efficiency, speed, and distance. The life span of most batteries is an estimated 100,000 miles. Less need for maintenance on fewer parts makes up for high battery replacement costs (estimated at $3,000).  Most EVs use one of the following batteries:
- Lead acid. Lead acid batteries were the first batteries used.  They are the  least expensive and most available. However, they last only 80 miles before needing a recharge.
- Nickel metal hydrate. These have a higher energy density and last up to 120 miles. Nickel metal hydrates are a popular battery for EV’s and hybrid cars.
- Lithium Ion. Lithium Ion is the newest EV battery.  It is the lightest and most energy efficient, with a range of up to 300 miles.

EV’s are more energy efficient than hybrids or standard, internal combustion automobiles. The amount of carbon EVs use, or their carbon footprint, is measured from their power source and emissions.  Though EV operation releases no emissions, it takes energy to charge the engine.  EVs have 55% to 99% fewer emissions than conventional cars, depending on the EV’s power source.  An EV charged from a power grid (wall outlet) has a carbon footprint that is directly tied to the utility's power source, be it renewable, natural gas fired generation or coal.

EVs are recommended for short distance travel.  However, manufacturers plan to release more affordable, long-distance EV models in the next few years.

Hybrids
Unlike electric cars, hybrids are widely available and gaining popularity. Operating with both an internal combustion engine and an electrical engine, hybrids provide the fuel efficiency of an electric car without the concerns of speed, driving range, or charging.  The electric engine dominates city driving. At around 40 miles an hour or at increased acceleration, the gas powered engine takes over and, charges the batteries. Once the car hits highway speed, both engines operate.  The light, hybrid engine combined with aerodynamic design allows for maximum fuel efficiency. The major issues surrounding hybrids are:

Cost. Hybrids are between $4-6,000 more expensive than conventional cars. Improved gas mileage and government tax incentives are ways to offset and eventually recoup initial cost.  Here's where you can find out about federal tax credits for hybrids bought in the U.S.

Fuel efficiency. According to the U.S. EPA, the average U.S. fuel efficiency is 23 mpg.  For hybrids, fuel efficiency can reach 55 mpg. Due to the dominance of the electric motor, hybrids get better gas mileage in the city rather than the highway.

Batteries. Hybrid cars use nickel metal hydride batteries which are less toxic than conventional nickel cadmium or lead acid batteries that are commonly found in conventional cars and electronics. They are fully recyclable and Toyota pays a bounty of $200 for each used battery. They are expected to last the lifetime of the car, and are under warranty for up to 10 years or 100,000 miles.

Retrofitting for Alternative Fuels
The market is full of alternative fuels for internal combustion vehicles. Some require engine modification, others are adapted for standard cars. Popular alternative fuels and modifications include:

- Vegetable Oil.  To use vegetable oil as a fuel, one must heat it before using to in a standard diesel engine. The most common method is to install a heat exchanger, an additional diesel tank, and a three-way valve. With this method, diesel starts the car as the exchanger heats the vegetable oil, and once warmed, the engine switches over. Conversion kits cost about $1200.

 For more about the availability of biofuels, visit Green Daily Travel.

- Biodiesel. Made from vegetable oil by removing the glycerin (thickening agent), biodiesel is combined with petrodiesel, and can be used by any diesel engine without modification.      

- Ethanol. Ethanol is the biofuel alternative to gasoline, derived from certain plants. Typically, ethanol is combined with gasoline to maximize performance. Any blend higher than 10% ethanol requires engine modifications. Referred to as fuel-flex vehicles, (these cars) are becoming increasingly available. To make a car capable of running on ethanol, its engine system must have an alcohol senor to adjust the fuel injection to create the proper air-to-fuel ratio.

- Compressed Natural Gas. Lower in greenhouse gas emissions, compressed natural gas (CNG) is an alternative to gasoline. For adaptation CNG cars need fuel-metering devices.  A standard internal combustion engine needs a pressure regulator to convert it from storage pressure to metering pressure, and a gas mixer or injector. Since CNG is a volatile gas, it takes up more space than liquid gasoline. Recent advances in composite materials include lighter alternatives for large tanks, which improve fuel efficiency. Though still few, home fueling systems and utility sponsored refueling stations are becoming more available.

On the Horizon
The fuel cell is the latest alternative yet to reach the mass market. Fuel cells create energy from the reaction of a fuel with an oxidant. The most common fuel combination is hydrogen and oxygen, though alcohol and hydrocarbons like methanol and diesel, are also used. The only waste of a hydrogen and oxygen reaction in the fuel cell is water vapor.

In addition, researchers are considering liquid hydrogen as an alternative fuel. Along with zero emissions, hydrogen has one of the greatest energy per unit of weight ratios of all available alternative fuels. The downside is that liquid hydrogen production requires much energy. Until sources of alternative, low-emission energy increase, hydrogen powered vehicles will have a large carbon footprint.

Rail

Because they can distribute more pounds per axle with little friction (using less fuel per ton of goods), rail systems emit significantly fewer greenhouse gasses than aviation and road transport. In the US, passenger and freight trains account for roughly 3% of the country’s total greenhouse gas emissions.  The two current primary fuel sources for rail are:

1. Diesel. Being the first alternative to steam locomotion, diesel dominates long range freight and passenger railways. This is particularly true in much of the US where wide-open space encourages an internal energy source.
2. Electric. Originally developed with overhead wires conducting electricity, electric trains have been used in urban or dense areas such as Europe. In addition to producing no source point pollution, they are less noisy, require less maintenance, and have a higher power/weight ratio than diesel trains. However, electric systems are more expensive, encouraging their use in areas with multiple stops.

Changes in the Industry
Fuel efficiency and alternative fuel sources are the primary goals of the rail industry. Innovations include:

- Biodiesel. Many rail systems are adding biodiesel to their fuel load. Britain’s high speed train, Thames Voyager, began running on 20% biodiesel in late 2007. Designers expect the new fuel to reduce the train’s overall emissions by 14%.

- Hybrid Locomotion. While trains use a combination of diesel and electric mechanisms for propulsion, new developments have lead to greater fuel efficiency and reduced emissions. Electro-diesel trains use either a diesel or electric motor tending to serve small and local markets. By contrast, a diesel-electric system operates much like full hybrid cars by using both engines for propulsion; utilizing regenerative breaking which stores the kinetic energy from breaking to apply later; and shuts off the diesel motor at slower, stop and go speeds. It is expected to reduce emissions by up to 90% and fuel usage by up to 60%.

Options for Train Travel
Though trains use fossil fuel for energy, they have the smallest carbon footprint of all of transportation methods. In addition to intercity rail lines operating within a municipality, train travel options include:

- Commuter trains that connect residential areas with commercial centers. These trains travel anywhere from 15 to 100 miles at speeds between 55 to 100 miles per hour. They have relatively frequent stops, are generally comfortable, and offer limited luggage space.

- High Speed Rail. Traveling over longer distances at higher speeds than commuter trains, these rail systems connect large cities. Planners designed high-speed rail with limited stops to compete with air and automobile transport.

- Long Distance Trains. Usually diesel powered and running at lower speeds, long distance trains connect far away regions, often crossing international borders. As aviation and car travel became more popular, long distance train travel declined.  Long distance trains are now largely used for touring and often include sleeping and dining cars.

On the Horizon
Research technologies for fuel efficiency, decreased pollution, and increased accessibility include:

- Hydrogen Fuel Cell Locomotion. The East Japanese Railway Company is working on the first hydrogen fuel cell, hybrid train. It produces zero greenhouse gas emissions.  Engineers are still working to increase the train’s speed and travel range.

- Superconducting High Speed Trains. These trains are known as the “train of the future”. By a process referred to as electromagnetic induction, these  trains are propelled by the repulsive force between the magnetic fields of the rail and the train, causing the train to rise above the tracks at speeds up to 350 miles per hour. Operating and energy costs are lower than high-speed trains, but maglevs (magnetically levitating trains) are incompatible with existing rail lines and require a whole new infrastructure. Only a few operate in Japan and China.

Ocean Transport

When aviation took over long distance travel, freight transport dominated ocean transportation. Recently, the UN reported that shipping emits 4.5% of the world’s carbon.  The UN projects it will grow 30% by 2020.

Problems with Bunker Fuel
Bunker fuel is the primary fuel for shipping. Also known as residual fuel, bunker fuel is the sludge waste of petroleum refinement. Though it emits less carbon, bunker fuel shipping emits 27% of global nitrogen oxide, and 20% of global sulfur. The UN has recently begun regulating its greenhouse gas emissions.

Changes in the Industry
Under increasing pressure to change to a cleaner fuel, the shipping industry has begun looking into the following areas:

- Adapting ships to use compressed natural gas and biodiesel fuel.
- Introducing diesel-electric hybrid vessels. These use a diesel motor for propulsion, and an electric motor for the onboard power source. They also use electric power while docked, reducing emissions.
- Designing wind power for cargo ships. . By placing high-tech sails on six masts on a 50,000 ton cargo ship, a Danish team hopes to utilize wind power for propulsion on the high seas. The ship also as a diesel engine for situations where wind is limited or going the opposite direction.

Options for Passengers
While ocean travel has decreased over the years, some methods still exist.

Ferries. Available for both long and short distance travel, ferries provide local transportation, carrying people from city to city, or to communities surrounded by water. Ferries often carry cars, and for longer distance travel, have dining and sleeping cars. Unlike cargo ships, many ferry systems incorporate alternative energy and fuel-efficient designs.

Cruise Ships. Modern day cruise ships are equivalent to ocean liners from the days before air travel. Emphasizing luxury and pleasure touring, cruises have little to do with getting from one place to another. The transatlantic Queen Elizabeth 2 and Queen Mary 2 closely resemble old ocean liners in speed and functionality, but operate largely as cruise ships. For more on environmental impact of cruise ships, visit Green Leisure Travel.

On the Horizon
Operating out of Hamburg, a new hybrid, hydrogen fuel cell, 100 passenger ship will start service in summer, 2008. Zemship will store enough hydrogen for up to three days of travel. Zemship (Zero Emission Ship) is funded by the EU.

What You Can Do

• To minimize the environmental impacts of transportation:
• Reduce Air Travel. For shorter distances consider taking a train, ferry, or even driving.
• Telecommute whenever possible.
• Purchase carbon credits to offset the impact of travel.
• Drive Less.
• Utilize public transit, bicycling, and walking whenever possible.
• Purchase a low-emission vehicle.
• Consider retrofitting your vehicle for alternative fuels.
• Invest in alternative transportation.
• Buy local to avoid the carbon footprint of goods transported by air, truck, or ship.

For more ways on how to reduce your environmental transport impact, visit   Green Daily Travel and Green Leisure Travel.