The fight against global warming

Global warming is real. Around the world, it is considered to be one of our era’s most pressing challenges and biggest threats. The U.N. Framework Convention on Climate Change estimates that more than 20 percent of global emissions of greenhouse gases are produced by the transport of goods and people. As a result, there is a pressing need for action, particularly by the logistics industry. New, more extensive measures to cut emissions must be taken. These include the use of alternative means of transport and energy sources as well as the more efficient use of current forms of energy.

Basic information about global warming

The greenhouse effect

Global warming is considered to be the rise of the average temperature of near-surface air and of the oceans. The term refers both to the process that has occurred in past decades and to the trends that are expected to occur in the future.
Of the many scientific explanations of this phenomenon, the one that seems the most plausible identifies the spreading greenhouse effect as the main cause. For this reason, this explanation - which is supported by the majority of scientists - forms the basis of the following section. But, it must be noted that other theories are espoused by many researchers. These include an increase in the sun’s activity and volcanic eruptions.
The greenhouse effect is considered to be the process of absorption and emission of infrared radiation by gases in the Earth’s atmosphere. For a full understanding of this effect, a description of a theoretical radiation budget for an Earth without an atmosphere must be provided first: In this case, unattenuated solar radiation hitting the Earth’s surface would be partially absorbed and partially reflected. The absorbed share would be converted into heat and would have to be emitted in a condition of balance within the infrared spectrum. Under these conditions, model calculations have shown that the average temperature of the Earth’s surface would be about -18°C.
When an atmosphere is included, the solar radiation hitting the Earth’s surface is hardly attenuated because the atmosphere in the visible spectrum is largely penetrable. But in the infrared spectrum, the radiation emitted by the surface is largely absorbed by the atmosphere and radiated in all directions. The infrared radiation can escape directly back into space only in so-called window areas. The infrared radiation that the atmosphere redirects to the Earth’s surface - which is also called counter-radiation - increases the energy supply on the Earth’s surface. A condition of balance can be created only if the surface temperature rises as well. This undisputed, natural greenhouse effect produces an average temperature on the Earth’s surface of +15°C.
An explanation of the additional greenhouse effect triggered by humans can be provided on this basis. As a result of the increased concentration of trace gases caused by humans, the penetrability of the Earth’s atmosphere is reduced, and counter-radiation is increased. The greenhouse effect is induced in particularly by the following gases: water vapor, methane (CH₄), ozone (O₃) and carbon dioxide (CO₂). For this reason, they are called greenhouse gases. Scientific studies show that carbon dioxide is one of the gases that contribute the most to the greenhouse effect.
In recent years, public interest in environmental questions has risen significantly. Some scientists, politicians and journalists also have discussed the risks associated with the greenhouse effect. The Kyoto Protocol negotiated in 1997 calls for a 5 percent reduction of greenhouse-gas emissions compared with 1990 by the year of 2012. The protocol took effect in 2005. By November 2007, 174 countries had ratified it.

Acute need for action by the logistics sector

Countries that have ratified the Kyoto Protocol are increasingly changing their political policies in terms of greenhouse gases. They have set ambitious goals and imposed new regulations on industry.
The U.N. Framework Convention on Climate Change estimates that more than 20 percent of global emissions of greenhouse gases are produced by the transport of goods and people. For this reason, logistics companies are called on to introduce efficient measures that will reduce their impact on climate change.
This need for action is expanding because investors increasingly consider companies’ sustainability practices in their investment decisions. Just like traditional stock indexes, global sustainability indexes have been developed, and these indexes measure companies in terms of their activities’ environmental impact and their strategies, among other things. One example is the KLD Global Climate 100 Index. It is designed to promote investments in companies whose practices have great potential for mitigating the immediate and long-term causes of climate change.
When it comes to their purchasing decisions, a large number of consumers also prefer those companies that have made a commitment to sustainability and environmental protection.

Reducing greenhouse-gas emissions

Greenhouse gases that are never emitted cannot contribute to global warming. Logistics companies are called on to avoid creating greenhouse gases to the greatest possible degree. There are a number of ways to achieve this goal. Some of them are described in the following section.

The use of alternative means of transport

One of the best ways to reduce consumption of fossil fuels and the emission of greenhouse gases is to change the means of transport being used. Two examples are the supermarket chain Monoprix in France and DHL in Germany.
In November 2007, Monoprix began to step up its use of trains to supply its supermarkets in the Paris region. Goods are taken by train to a central warehouse about 30 kilometers from Paris. It is only then that trucks are used to supply individual retail outlets. Currently, 27 of 60 stores are being supplied in this manner. If goods for all 60 supermarkets were delivered by train as planned, five trains would transport a total of 185,000 tons of goods every day. This would mean a reduction of up to 10,000 truck trips each year and a significant cut in greenhouse-gas emissions.
This program is just one of many. As far back as 2003, Monoprix began to expand its use of inland-waterway shipping to transport goods from non-European countries. Just a few years later, 1,300 TEUs TEU were being carried on domestic water routes, cutting carbon-dioxide emissions by 50 tons compared with pure truck transports.
Overall, the package of measures introduced by Monoprix is increasing costs in the supply chain Supply chain . Nonetheless, the company’s management thinks that this strategy will pay off in the middle term because it polishes the company’s environmental image.
At DHL, the train has replaced the truck to a certain extent. For instance, the “Parcel InterCity” provides overnight connections to major economic centers. The concept is based on the use of passenger-train locomotives that can reach speeds of up to 160 km/h. The Parcel InterCity has priority over all other trains and offers superior speed compared with road-based transports. At comparable costs, the attractiveness of rail transports rises considerably. A train can replace up to 70 trucks - fewer emissions, less noise and increased energy savings are the result.

Price Development of Crude Oil and Kerosene

The use of alternative energy sources and drive systems

As a result of the increased awareness of climate change and the comparatively high price of oil, the focus has shifted to alternative energies in recent years. As part of this new direction, many different technologies are being explored, and some have already been successful in the marketplace.

Fueling of a biogas vehicle

Vehicle with fuel cell

The following section provides a brief description of these technologies:

Batteries store chemical energy, which can be dispensed in the form of electricity to the drive system of a vehicle. Various types of batteries can be used for this purpose. Lithium-ion batteries - like those used in cell phones - supply the best performance. But they are relatively expensive. The batteries can indeed be partially charged by converting the energy produced by braking. But they are largely dependent on the normal electricity-supply network. For this reason, the environmental friendliness of batteries as an energy source depends on the manner in which network electricity is produced.
Bioalcohol like ethanol or methanol can be mixed with other fuels used by internal combustion engines. Compared with crude oil, it has environmental and possible long-term commercial benefits. Ethanol appears to be the most interesting bioalcohol because it can be produced from a variety of agricultural products and is non-toxic.
Biodiesel is a fuel comparable to diesel - it is produced by the transesterification of vegetable oils or animal fats. It can be used - by itself or mixed with conventional diesel - in normal or slightly modified diesel engines. Biodiesel is biodegradable and about 60 percent better than conventional diesel in terms of carbon-dioxide emissions. But, significantly more nitrogen oxides are created by its combustion.
Biogas is created by the oxygen-free, biological decomposition of organic matter. It consists primarily of carbon dioxide and methane, and the methane serves as the energy source. Biogas can be obtained as a by-product from the fermentation of household garbage.
Compressed natural gas is also an environmentally friendly alternative to gasoline and diesel fuel. It is produced from the compression of gases that occur in nature, including methane, ethane, propane and butane. The share of methane alone is between 70 and 98 percent. Compressed natural gas is stored and transported in pressure tanks. It is primarily used in large vehicles and buses because it cannot be liquefied and requires a relatively large amount of space. Still, natural gas is a fossil fuel whose use cannot be seen as being entirely environmentally friendly.
Liquefied petroleum gas or autogas is not to be confused with compressed natural gas. It remains in a liquefied state at room temperature even under relatively low pressure. The gas, which consists of propane and butane, is used in combustion engines. It reduces carbon dioxide emissions by about 20 percent compared with conventional gasoline.
Vegetable oil is produced from plants like soy beans, sunflowers and peanuts. It is obtained directly from the plants or from recycling vegetable oil. The food industry uses huge amounts of vegetable oil - for purposes such as deep frying. Vegetable oils have about the same energy content as diesel fuel, but cannot be used in normal diesel engines because of differing physical characteristics. They are renewable sources of energy. During combustion, nearly 100 percent less greenhouse gases are emitted.
Hydrogen can also be used as a fuel for internal combustion engines. The technology is comparable to the use of gas. Hydrogen is viewed as a possible successor to aviation fuel. This possibility is being studied in research supported by the European Union that is called the CYROPLANE project. In terms of the automobile market, several hurdles still have to be cleared. A completely new filling-station network must be built. As a result of the comparatively low energy density, large-volume tanks must be integrated into vehicles as well. This means that hydrogen’s particularly positive environmental characteristics are offset by the production and distribution needs.
Fuel cells are viewed as a very promising technology. A fuel cell is a Galvanic cell in which the chemical reactive power of a continuously supplied fuel and of an oxidizing agent is converted into electrical energy. Thus, a fuel cell is not an energy store but an energy converter. The energy used to produce electricity is supplied to the fuel cell. The hydrogen-oxygen fuel cell in which hydrogen serves as a fuel and oxygen as an oxidant is extremely beneficial from an environmental point of view: The only by-products of the reaction are heat and water. Because of the need to use hydrogen as a fuel, fuel cells have the same weaknesses as those previously described in the hydrogen section. Even though the fuel cell has been used for some industrial purposes for years, much more developmental work must be done before it can be employed on a widescale basis: Fuel cells are expensive, fragile and short-lived.
Hybrid drive systems use two different sources of energy. Several combinations would actually be possible. But the term usually refers to a combination of gasoline or diesel and batteries. Large numbers of hybrid vehicles are already on the market, and their sales are climbing rapidly. The combination of two technologies minimizes the weaknesses of the individual systems: Gasoline or diesel fuel is burned when power is needed. The batteries are used at low speeds and are charged when the brakes are applied. The overall outcome is lower fuel usage and, as a result, reduced emissions of greenhouse gases.

The efficient use of energy

In addition to the use of alternative fuels, the emission of greenhouse gases can be lowered by using energy sources produced from crude oil more efficiently. The following section describes a few of the potential approaches.

Environmental driving style: A change in driving style has a direct impact on fuel consumption and emissions. By thinking ahead, a driver can reduce fuel consumption by 2 to 10 percent and lower costs to the same extent. For this purpose, DHL has its own driver-training team that teaches courier drivers about possible changes in driving behavior, including timely lane changes and early shifting.
Transport telematics: By incorporating as much up-to-the-minute information as possible into route planning Route planning , traffic jams can be avoided and fuel conserved. The topic is addressed in-depth in the Chapter "Route planning and route-transport telematics".
Fleet renewal: By investing in modern fleets, fuel consumption can be cut significantly. This applies to every means of transport, but especially to aircraft. Plane manufacturers continue to develop more and more efficient aircraft. They are able to cut fuel consumption by improving aerodynamics, reducing weight and, above all, using more efficient engines. These developments are being advanced by the European Commission’s VITAL project, which is working to achieve a 7 percent reduction in CO₂ emissions. Lower fuel consumption has become one of the most important sales arguments in the entire aviation industry - primarily for cost reasons but also out of environmental considerations.

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