Aspects of the climate change

Definitions:
weather: The state of the atmosphere at a given time and place, with respect to variables such as temperature, moisture, wind velocity, and barometric pressure.
climate: the variability or average state of the atmosphere over many years
climate change: the variation in the Earth´s global climate or in regional climates over years

One of the most current issues in politics or wherever in these days is the debate about climate change. Scientists confirm that between 1906 and 2005 temperature has grown about 0,74 °C and while between 1976 till today the highest increase has been measured. On top of that the year 2005 has been the warmest year since climate researches had been started. Also oceans show higher temperatures of about 0,6 °C. To ordinary human beings this number doesn´ t seem to be threatened but you always have to remember that the mean temperatures in the last ice age have only been 6°C less .Now they´ re discussing whether this global warming has just natural causes and is an indicator to show the change between ice ages and warm periods. They also mention a lot of natural factors affecting climate change, as for example solar- and orbital variation and oceans variability.

One key word which is often connected with climate change is the greenhouse effect. You can subdivide it into two kinds:

a) natural greenhouse effect
Without the natural greenhouse effect, life on earth won´ t be possible, because temperature will be about – 18°C, not an average of todays 15°C.This fact can be due to two thirds to water vapour of the atmosphere and the rest to carbon dioxide, methane, nitrous oxide, atmospheric ozone and CFC. They allow short wave solar radiation to pass to earth, but they reflect long wave radiation from earth, as well as clouds.



b) man-made greenhouse effect
Beginning with the industrial revolution in the 1850s and accelerating ever since, the human consumption of fossil fuels has elevated carbon dioxide levels from a concentration of about 250ppm to more than 380ppm today. Researchers assume that the concentration will still increase at more than 560 ppm till the end of the 21st century. In addition to that they´ ve also measured higher concentration of methane, so the natural greenhouse effect is intensified.

Causes of the increase of greenhouse gases

a) fossil fuels
As already mentioned, the extreme increase of emissions of CO2 originating from the burning of fossil fuels has the largest effect on global warming. Because of the high mechanisation in every part of production there´ s a demand for more and more fossil fuels. Even in developing countries and above all in emergent nations it isn´ t unusual to have a car. Many companies prefer building their factory in these countries, because the environmental conditions aren´ t as strong, they don´ t care about filters for example.

b) deforestation
Another reason is the deforestation in many developing countries, because of their need to have more field for their growing population. One solution is the clearance so there is more room for livestock grazing and the cultivation of crops. You call this “slash-and-burn-cultivation”, which has got a double effect on the climate. One the one hand much CO2 is produced by burning the wood and on the other hand the climate-regulating role forests play doesn´ t exist anymore. Wood is often used as fuel in developing countries because it isn´ t that expensive. Also industrial countries have to be blamed because there is a huge inquiry for exotic woods and because they are very rare, thousands of hectares have to be destroyed.

c) livestock farming
Because of the higher consumption of meat factory farming is necessary, where methane is emerged from the digestion.

d) landfills
Global methane emissions from landfill are estimated to be between 30 and 70 million tonnes each year. Most of this landfill methane currently comes from developing countries, where the levels of waste tend to be highest.

Scientists still are not sure about the real degree of climate change but they predict an increase of 1,5°C till 4,5°C. They can´t commit this because it depends on the industrial development and possible mechanics that act to amplify or reduce effects, also called positive or negative feedbacks.

Positive feedbacks:

• When the temperature of the oceans is rising, the water isn´ t able to store up as much CO2 as before, so the CO2 will remain in the atmosphere where it leads to heating
• As the Earth's surface heats up, some ice and glaciers begin to melt, exposing either bare ground or ocean, both of which have lower albedos (reflectivity) than ice. With a lower albedo, the exposed surfaces reflect less incident solar radiation, and the additional absorption causes further heating. Further rises in temperature initiate further melting of snow and ice, with further exposure of more energy-absorbent terrain
• The warming of regions in high latitudes may cause an unfreezing of the permafrost soil, located for example in Sibiria and Alaska, so huge amounts of methane will escape, because of the extinct biomass which was kept under ice and snow over many years.

Negative feedbacks:

• As the Earth warms, so the rate of evaporation from the (warmer) oceans increases, supplying the atmosphere with more water vapour which is conducive to enhanced cloud formation. With greater global low cloud coverage, more incident radiation is reflected, reducing radiative forcing and leading to a lowering of the global temperature.
• Because of higher CO2 Concentrations in the air, plants will grow faster and in the same time they will consume more CO2 or bin this in their leaves and clades.

Impact

• A rise of sea levels inevitably occurs. At the moment rises of about 3-4 cm each decade are expected, but they depend on the speed of melting glaciers. Especially threatened of floodings are little islands and coastal areas.
• Oceans will take much more CO2 because of their warming and become acidic.
• Glaciers of the Alps and other high mountains will disappear, other ice sheets and glaciers may melt.
• Heatwaves will be more intense and more frequently also in regions of Central Europe.
• Rainfall will decline, especially in summer, whereas heavy rains will gain because of higher evaporation.
• New deserts will arise, existing will spread.
• Areas under cultivation will reduce and mainly in developing countries will subsist more famines.
• Water supply in dry regions may become more difficult.

Concrete examples of possible impact

Winners:

a) India
Today most parts of the continent are steppe and only receive rain in time of the monsoon. It is possible that till 2100 India will be part of equatorial clime and so it may rain the whole year so there will be fertile land and higher yields.

b) Russia and Mongolia
Especially in North Asia it is too cold in order to have agriculture, only coniferous trees are growing. It is quite possible that temperatures will rise, growing seasons will extend, so there are better chances for farming.

c)China
In China the climate change will bring more precipitations areas with loess will become even more fertile.

Losers:

a) Mediterranean countries
In Spain, Italy, Tunesia and other neighbouring countries the steppe will spread and prevent the current cultivation of olives, date palms and wine. The likelihood of droughts and forest fires will enhance.

b) Brasilia
In the first instance the east of Brasilia, which is in the zone of equatorial clime, will suffer from the spreading of steppe and only the drinking water supply will be a problem

c) the Midwest
At the moment the supply of wheat corn and can be assured in the area of the Great Plains but in the next summers there will be more droughts so the farmland will more and more dry up and get infertile. The water supply system which is used nowadays won´ t be sufficient

Political measures
The Intergouvernmental Panel on Climate Change (IPCC) has been established in 1988 by the UN. Principal tasks of the organisation is the report on the current situation, estimation of possible effects, setting up of regulating measures and conviction of nations to participate on the programme. The Kyoto Protocol is a protocol to the International United Nations Framework Convention on Climate Change (UNFCCC) with the objective of reducing greenhouse gases that cause climate change. It was agreed on 11 December 1997 in Kyoto and entered into force on 16 February 2005. Countries that ratify this protocol commit to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if they maintain or increase emissions of these gases. So far there are 189 members. Disputed is the abstention of the USA and Australia, because they are two of the countries which produce most CO2. The protocol plans to reduce emissions of greenhouse gases at an average of 5,2 % till 2012. Many see the costs of the Kyoto Protocol as outweighing the benefits, some believing the standards which Kyoto sets to be too optimistic, others seeing a highly inequitable and inefficient agreement which would do little to curb greenhouse gas emissions.

Political possibilities to reduce greenhouse gases

• As one of the first states Germany has backed out of the use and production of CFCs, which are especially blamed for the depletion of the ozone layer
• subsidy of renewable primary products
• make companies to pay taxes on released CO2 when they don´ t use special filters
• special conditions for the automobile industry, built their cars more fuel saving, with less CO2 expulsion
• use of nuclear energy, which is now highly discussed, because much CO2 could be saved up

Individual possibilities
Also the population can change their habits in order to reduce CO2 emissions. Some suggestions:

• Use of more renewable energy sources, like geothermal energy, solar energy and wind power
• Make heating, lighting and domestic appliances more energy-efficient
• Use of equipment that conserves more energy in buildings, so that less energy is wasted
• Recycling of waste
• Consumption of regional products to prevent far routes of transport
• Consumption of vegetable food instead of animal food
• Locomotion by bus or train

Quellen:

• wikipedia.de
• wetter-klimawandel.de
• unep.org
• ipcc.ch
• literature: wetter und Klimaphänomene

Lisa Zumpf, 20.02.08

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