The economic advantages of gaslight make its disadvantages negligible. Moreover, any possible savings from conversion to electric light would be delayed by decades.

- Gas lamps have higher maintenance costs than electric street lamps because incandescent gas mantles need to be replaced regularly.

- Gaslight technology is not inherently faulty. On the contrary, over the past years Berlin has invested in state-of-the art gaslight technology which ensures easy and reliable gaslight operation. This technology includes modern electronic ignition mechanisms, control sensors and electro-magnetic valves. If increased faultiness of gaslights did occur, this is largely due to the poor maintenance work in recent years (see below).

- Gas lamps have greater life-spans than electric lamps. The resulting savings make their higher maintenance costs negligible. Gas lighting fixtures and lamp posts stay in working order 2-3 times longer than their electric counterparts. The maximum life-span of electric lamp posts is 40 years. Electric lighting fixtures need to be exchanged approx. twice as often or every 20 years (Source: German Federal Institute for Materials Research and Testing). By contrast, gas lamp posts remain in working order for over 100 years.The posts owe their long life to the gas flowing through them. The gas displaces all oxygen, thus, preventing any corrosion on the posts' inside. While gas lighting fixtures only need to be exchanged twice every 100 years, 5 new electric lighting fixtures and at least one electric new lamp post are required during the same time period.

- Gas lamps generate less waste than electric lamps. Not only do gas lighting fixtures and lamp posts need to be exchanged less often than their electric counterparts, the majority of materials used in gas lamps can be easily separated, recycled and disposed of. Gas lamps are largely made of non-toxic metals, enamel, glass and ceramics. The amount of mantle ash, which needs to be permanently disposed of, amounts to a comparatively minor 2.5 -3 kg per year for all of Berlin's gas lamps together. In contrast, electric lighting fixtures, which need to be exchanged every 20 years, constitute electronic scrap. The entire electric lighting fixture has to be permanently disposed of as hazardous waste. Therefore, the approx. 39,000 new electric lamps will mean tons of additional hazardous waste per year.

- Gas distribution at no extra cost. In contrast to popular assumption, Berlin's gas lamps do not have a separate gas distribution system, which has to be maintained at extra cost. Instead, Berlin's gas lamps are connected to the city's central gas distribution system, which also provides gas to Berlin's businesses, private households, etc. The entire system was last modernised in 2003.

- The new electric street lamps will not provide any savings for decades to come. Experts estimate the cost of dismantling the gas lamps and replacing them with electric lamps at 170 million Euro. This large sum cannot be redeemed by the Senate's estimated savings on maintenance and energy consumption. If one takes interest and debt repayment into account, actual savings will not occur for decades. Additionally, this calculation, as published by the Senate, still neglects a possible increase in electricity prices. Moreover, this calculation does not take into account the already considerable investment made into modernising Berlin's gaslight technology in recent years.

- Berlin's gas street lamps have been poorly maintained since 2001.

2001 saw the privatisation of Berlin's street lighting. The managing company subcontracted the maintenance work to companies, which to some extent lack the necessary expertise to service street lighting, gas lamps in particular. Since 2001 all of Berlin's street lights, gas and electric, have been serviced only in a very poor and incompetent fashion. The lamps are not serviced at standard intervals. Moreover, the lamps' external care has been dropped entirely. No rust protection or any kind of finish has been applied.

Gas lamps, especially, depend on regular servicing because their injectors and ducts need to be cleaned; a task, which in itself requires little effort. If this task is neglected, however, the mixture of gas and air fuelling the light becomes unbalanced. Consequently, the gaslight smoulders and cannot reach its full lighting capacity. Thus, it is little wonder if gas lamps have failed more often in recent years. We cannot help but wonder that the Senate welcomes this poorly maintained state of Berlin's gas lamps. It serves to give Berlin's citizens the impression that gas lamps are ailing, that the gaslight technology is no longer working properly and, therefore, needs to be removed.

The Senate overstates the capacity of electric lighting to reduce environmental pollution, including CO2-Emission. Additionally, Berlin's gas street lighting has its own set of environmental benefits which need to be considered.

New electric lighting will not reduce environmental pollution as much as promised.

- The gas lamps' CO2 emission is comparatively minor. In 2012 Berlin's gas street lighting generated approx. 40, 000 tons of CO2. This amount only constitutes 0, 17% of Berlin's overall CO2 emission. Therefore, gaslight is not a significant contributor to Berlin's carbon footprint. To put gaslight's CO2 emission further into perspective: The brown coal/lignite-fired power station Jänschwalde, which produces electricity for Berlin, generated 24,3 million tons of CO2 in 2011 (European Emissions Register). In other words, Jänschwalde produces the annual CO2 emission of Berlin's gaslights twice a day. In light of these numbers, we challenge the Senate's position that gaslight needs to be abolished due to its amount of CO2 emission.

- Electric lamps create more waste than gas lamps. Electric lighting fixtures have shorter life spans and need to be exchanged 2-3 times more often than gas lighting fixtures. Additionally, not only the flourescent tubes but also the entire lighting fixtures need to be disposed of as hazardous waste. Partially, this is due to the toxicity of the mercury used in florescent tubes. The flourescent tubes of models such as 'Jessica' (Sympatex) contain up to 5mg of mercury per lighting fixture. Thus, the approx. 39,000 new electric lamps will generate tons of additional hazardous waste per year. The disposal of this hazardous waste creates additional CO2-Emission, which the Senate currently does not account for in its calculations. Hazardous waste needs to be transported to special disposal sites by lorry. These disposal sites are spread far and wide across the country. In contrast to electric lamps, gas lamps largely consist of materials that can be easily separated, recycled and disposed of. Additionally, the ash of all of Berlin's incandescent gas mantles amounts to a comparatively minor 2-3kg per year. This ash and minimal amounts of electronics are the only waste from gas lamps which needs to be permanently disposed of. Moreover, in recent years, hazardous waste from gas lamps has been further reduced through the introduction of solar-powered ignition mechanisms. These have eliminated the use of batteries in 10,000 gas lamps.

- Electric lighting causes additional environmental pollutants. Currently, a large part of the electricity for Berlin's street lighting derives from the lignite-fired power plant Jänschwalde (see below). The lignite-based electricity production creates significant amounts of CO2 and other environmental pollutants, such as, nitrogen oxides, sulphur oxides, mercury, lead, arsenic and atmospheric particle matter (European Emission Register 2011). While Jänschwalde is required to contain this emission as best as possible, the filters used have to be permanently disposed of as hazardous waste. Based on Jänschwalde's emission data, the European Environmental Agency (EUA) estimates that the power station causes damage to human health and the environment of up to 2 billion Euros.

- Pollution caused by electric light unlikely to change. Future investments in the technology of Jänschwalde to improve its environmental impact seem unlikely. The power station Jänschwalde is the most recent of all three remaining power plants in the Lausitz area. Despite this, Jänschwalde however uses the most out-dated technology available. New investments in the plant appear unlikely when all plans of modernisation, for example, a new unit for the removal and injection of CO2, were abandoned by Vattenfall in 2011. Additionally, the source of the electricity for Berlin's street lighting is unlikely to become more environmentally friendly. The Senate does not plan to switch from lignite-based electricity to 'green electricity' because Berlin would not be able to afford the costs.

- In contrast to electricity, gas is a primary energy source and is only consumed locally. In total, the carbon footprint of the extraction and transport of natural gas is much smaller than the carbon footprint of lignite-based electricity production and of the electricity's transportation.

- CO2 emission from gas street lamps in Berlin will further decrease. Of all fossil fuels, the burning of natural gas produces the smallest amount of CO2-emission (Source: Energy Information Administration 1999 (LINK zur Quelle, URL siehe Absatz-Ende)). GASAG, Berlin's gas supplier, presently feeds over 10% carbon-neutral biogas into Berlin's gas distribution system. GASAG plans to increase this percentage in the coming years. Moreover, even greater CO2 savings will be possible in future by using biogas. Currently, a Power-to-Gas method is being developed which will employ solar/wind power to create biogas with a methane content of up to 95%. This method almost entirely eliminates biogas' natural CO2 content (up to 45 %). At the moment, biogas still has to be separated from its CO2 content before it can be fed into the gas distribution system. (Source: Frauenhofer- IWES (LINK zur Quelle siehe dt. Seite)).

http://www.eia.gov/pub/oil_gas/natural_gas/analysis_publications/natural_gas_1998_issues_trends/pdf/it98.pdf

- 'Saving' often just means 'transfer'. Unfortunately, any proclaimed 'saving' of emission has to be examined critically. Due to so-called 'emission trading', CO2 emissions 'saved' in one area (for example, by abolishing Berlin's gas street lighting) may then be emitted somewhere else. No actual reduction of CO2 emission occurs. The emission is simply transferred to another place.

- The Senate's lighting policy is contradictory. The Senate's choice of operational company subverts the Senate's argument to abolish gaslight for environmental reasons. Although environmental organisations have repeatedly levelled strong criticism against Vattenfall Europe, Berlin's Senate chose this company to manage Berlin's street lighting (gas and electric) for the next seven years. The environmental organisation Greenpeace has ranked Vattenfall Europe among the most environmentally damaging companies worldwide.

The lignite-fired power plant Jänschwalde

Currently, a large part of the electricity for Berlin's street lighting derives from the brown coal/lignite-fired power station Jänschwalde (Lausitz). Not only does lignite-based electricity production create large amounts of CO2 emission, but the power station Jänschwalde also has exceedingly low efficiency and environmental ratings. According to the managing company Vattenfall Europe, Jänschwalde only reached a net efficiency of 35-36 % in 2011. For the same year, the European Emission Register reports 24.3 million tons of CO2 emission. This means, over two thirds (or approx. 15.7 million tons) of CO2-emission were generated only to produce electricity from coal. All the generated energy is eaten up by the production process. Actual electricity is only won from the fire-power of the remaining third of lignite, which generates the remaining third of 24.3 million tons of CO2. As early as 2007, the World Wide Fund for Nature (WWF) declared Jänschwalde to be the 4th most climate damaging power station in Europe, the 7th worldwide.

Additional environmental benefits of gas street light include:

- lower levels of light pollution

Electric lighting causes approx. 50% of urban light pollution ('Dark Sky Syndrome').

Atmospheric dust particles reflect the light creating great light domes above cities ('skyglow'). In comparison to 150 years ago, Berlin's sky on a clear night is already ten times brighter than it used to be. On an overcast night, the sky can be up to 1000 times brighter (Spiegel Online 2010 (LINK zur Quelle, URL siehe Abschnitt-Ende)).

http://www.spiegel.de/wissenschaft/natur/lichtverschmutzung-bei-nacht-der-himmel-ueber-staedten-faerbt-sich-rot-a-848985.html

The white light quality of the electric lamps which the Senate plans to introduce, will increase the negative impact of present light pollution with incalculable effects on human health and wildlife. Particularily, the UV-light and blue light components are problematic. Human beings and other mammals are especially sensitive to blue light, which, among other things, decreases their natural ability to fall asleep (Lockley 2009 (LINK zur Quelle, siehe Abschnitt-Ende)). On the contrary, insects are automatically drawn to UV-light (see below).

http://www.britastro.org/dark-skies/handbook.html

In contrast to electric light, the light spectrum of gaslight does not contain UV light or blue light. Red light, predominant in gaslight has been shown to have the least effect on human-being circadian rythms (Cheung 2009 (LINK zur Quelle,siehe Abschnitt-Ende )).

http://today.uchc.edu/headlines/2007/nov07/graveyard

- conservation of wildlife, in particular of insects

Nocturnal insects are particularly drawn to the white-blue light of fluorescent tubes. This light is similar to the light of moon and stars, which insects use to navigate. One electric street lamp with a compact fluorescent source of light (e.g. 'Jessica' by Semperlux) kills approx. 150 insects per night. The electric lamps now replacing the 8,000 in-line lamps will exterminate 1.2 million insects every night.

Experts such as Professor Emeritus Gerhard Eisenbeis estimate that every night billions of insects fall prey to electric street light across Germany. The professor is a zoologist from Mainz, who conducted his main research in soil biology and forest entomology. He calls attention to the key role insects play in all terrestrial ecosystems, not least, as a vital part of the food chain. In urban environments, species such as bats and insect eating birds depend on the presence of a large insect population. Its decline causes the decline of all insect eating species (Source (LINK, URL siehe dt. Seite)). Over time, a massive demise of insects will create an ecological imbalance with consequences incalculable as yet.

In contrast to the electric fluorescent tubes, gaslight does not contain UV light. Therefore, gas street lamps do not attract and kill insects.

- conservation of Berlin's trees

The dismantling of Berlin's gaslights (e.g. in-line lights) greatly damages tree roots.

The removal of each gaslight requires two excavation pits. Thus, dismantling 8,000 in-line lights creates 16,000 excavation pits. Trees grow close to almost every site. The full extent to which the trees have been damaged will only become visible over the next months, even years.

Gaslight has additional value for human well-being and safety:

- high quality light

Gaslight shines glare-free and casts a clear-cut shadow. Moreover, gaslight depicts colours almost naturally (as they appear in daylight). Thus, gaslight fulfils safety standards. The performance of the new electric lamps is much poorer. (Comparison: four mantle in-line lamp approx. 5 Lux, nine mantle in-line lamp approx. 12 Lux, electric lamp 'Jessica' up to 2.0 Lux. Source: Baukammer Berlin).

- aesthetically pleasing

Most people experience gas street light as more pleasant than electric street light. This is due to the difference in light colour. While gaslight is yellow-golden, electric fluorescent light shines blue-white. Thus, gaslight contributes to one's quality of life. Estate agents, house owners and property developers are all well aware of this. They always advertise the local existence of gas street lighting as a special feature.

The Senate's Department for Urban Development has recently stated that LED lights imitating the gaslight spectrum will only be installed at a very few, select locations. Thus, these lamps are currently not a city-wide alternative to gaslight.

- economic drawbacks

The price of LED lamps is too high for city-wide LED lighting to be feasible. Moreover, LED light technology is still in the stages of early development. As of yet no scientific evidence exists whether LED lamps really last 5-10 years or longer. However, the experience so far indicates that very bright LED light has reduced the life-spans of the lamps. This is due to the high temperatures the LEDs have to endure. Additionally, the LEDs' light yield decreases over time, further decreasing the time-span of their use.

- environmental drawbacks

The production of LEDs utilises "rare earth elements" (very rare and precious materials) which are environmentally problematic.

Moreover, the LEDs' production in and shipment from the Far East produces considerable amounts of CO2 emission and costs. Finally, LED lamps have to be disposed of as 'electronic waste'. Their recycling is considered complex.

The Senate's plan makes only one single comment on the cultural aspects of street lighting. Unfortunately, this comment sounds quite banal: 'Public lighting... forms the cityscape'. In its assessment of Berlin's historical gas street lighting, the Senate entirely neglects all aspects of industrial and cultural history.

Berlin's gas street lighting is unique worldwide. It constitutes a valuable technological and cultural heritage. The gaslight's form and variety has only been preserved through Berlin's especial history.

Such significant cultural heritage must not be sacrificed for the sake of the alleged need to economise.

Scholars consider gaslight as one of the driving forces of the industrial and indeed social revolution of the 19th century. The development and spread of gaslight significantly changed urban everyday culture. In 1826, the first 26 gas street lamps were ignited on the street Unter den Linden. One hundred years later the German capital bore the sobriquet 'Gasopolis'.The city had become the gaslight industry's heartland. Moreover, many innovations in gaslight technology originated in Berlin. The great variety of posts and chandeliers, some over 150 years old, speak of the development of lighting culture. Moving among Berlin's gas street lamps, we are still able to recognize and experience this culture everyday.

Recently an expert report has attested to the heritage significance of Berlin's gas street lighting. In contrast to the Senate's preservation order, this expertise qualifies both the external form and the operational mode of the gas lamps for monument status.

Gaslight forms the cityscape

The typical form and the special, pleasant light of gas lamps form the appearance of many Berlin districts. The majority of Berlin's gas street lamps stand in western districts. The area Frohnau has the highest gas lamp concentration. Ninety-eight percent of the area's streets are gas lit. Additionally, the following areas still contain a lot of gaslights: Zehlendorf, Charlottenburg, Wilmersdorf, Lichterfelde and Lichtenrade. In all of these areas, gas lamps are an integral part of their environment's identity.

Thus, Berlin may lay claim to the unique feature of being a 'Gas street lamp-Metropolis'.

Gas street light as a tourist attraction:

Although Berlin's gas street lighting constitutes a unique cultural heritage, the city parliament has so far failed to recognise the potential of gas street lighting for tourism.

By contrast, other capitals around the world develop gaslight as a tourist attraction. For example, London offers bus tours themed "Visit London by Gaslight". Moreover, Prague has recently installed 500 new gas lamps on the Charles Bridge and the historical Coronation Route. Similarly, Warsaw has begun with the installation of gas lamps.

As 'Metropolis of Gas Street Lighting' Berlin has a real chance to develop its existing gas street lamps for tourism; thus, tapping their full economic potential.