Energy and environmental problems

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Introduction

In these days, everybody seems to be talking about the environmental problems. There are thick headlines about global warming in the newspapers, ecological products sell like never before and politicians hope to get votes trough telling us they’re going to stop the pollution. But in fact, what is this all about? How crucial is the situation?
The public is told to replace energy coming from fossil fuels with renewable energy, and there’s a whole market of these environmental-friendly products with persons getting a big deal of money out of our will to save the environment. Why is renewable so much better than fossil energy?
Can I, as an individual, make a difference?

Environmental problems

Global warming
If it wasn’t for the gases which the atmosphere contains, the Earth would be to cold to host any life at all. All radiation from the sun would, after bouncing on the Earth’s surface, escape leaving no warmth on it.
Thanks to the gases in the atmosphere, the greenhouse gases, of which carbon dioxide (CO2) could be considered the most important, only some of the radiation manages to escape. This is because the greenhouse gases only let short wavelength radiation, the radiation that comes directly from the sun, pass whereas the long wavelength radiation, the radiation that has bounced on the Earth’s surface, is reflected back to the Earth.
But since human started to burn fossil fuels and thus emit a surplus of greenhouse gases, their ability to maintain an appropriate global temperature is put out of balance. Too much long wavelength radiation is reflected onto the Earth; therefore we’ve got what’s called the global warming.

Global warming will damage or even eliminate entire eco systems, as the current changes of climate go much faster than evolution and emigration can save threatened species. Glaciers end permafrost on the North and the South Pole will melt, leaving no habitats for the unique creatures living there. This ice will in melted form increase the sea level, something that will come to cause great damage on coasts worldwide.
Scientists suspect that a higher temperature on the surfaces of the oceans will give power to winds and accordingly increase the number and the power of windstorms.

The amount of human-emitted greenhouse gases is currently increasing, and will proceed on that way if we don’t go from words to action in decreasing the utilization of fossil fuels. Everybody in the developed countries, from the biggest companies to the smallest individual, has to do something. A whole lifestyle must be changed.


The ozone layer
In the upper atmosphere, also called the stratosphere, there is a layer of a greenhouse gas called ozone (O3). This ozone is formed when UV-radiation from the sun hits a normal oxygen molecule (O2), and it is also broken down to O2 again when UV-radiation hits the ozone molecule. In this way, the amount of ozone stays the same and most of the UV-radiation (about 97-99%) is absorbed.
Scientists have shown that exposure to UV-radiation is harmful to humans and animals as well as plants, with the conclusion that the ozone layer is essential for the well-being of all Earth’s life forms.

But exposure UV-radiation isn’t the only way of which ozone can be broken down; a number of human-emitted gases are able to break down the ozone as well. The most important of these are the CFCs, an abbreviation for chlorofluorocarbons. CFCs have been utilized in, for example, fridges, air conditioning-systems and cleaning agents.
The emitting of these gases has caused a loss of stratospheric ozone, which will be hard to recover despite the international agreement to cease all production of CFCs. This is because the CFCs will remain in the stratosphere for many years.

Acidification
When burning fossil fuels; especially coal but also other; sulphur dioxide (SO2) and nitrogen dioxide (NO2) are emitted into the atmosphere. As they react with the rain water, the outcome will be the strong acids; solutions of low pH; sulphur acid (H2SO4) and nitric acid (HNO3) according to these formulas:

2 SO2 + H2O H2SO4 + O
NO2 + H2O HNO3 + H

This process is called acidification and it damages the places where the rain containing acids; the acid rain; falls. Animals and plants are developed to survive with the level of pH the rain naturally is of, and can’t handle acid rain. On places frequently exposed to acid rain the plants and animals will die.
But this isn’t the only way of which acidification harms the environment. Sulphur acid and nitric acid releases heavy metals and minerals from the soil and bring those into the groundwater. In quite the same way, acid rain corrodes ancient buildings and monuments.

Fortunately we’ve managed to decrease the amount of acid rain through decreasing the emitting of sulphur dioxide and nitric dioxide; thanks to e.g. installation of desulphurization systems and the move away from coal as a fossil fuel, as coal contains sulphur. But acidification is still a mayor environmental problem which we need to be aware of, and though it might seem so, it can’t be solved in one area alone as the acid rain can travel a great distance from the place of emitting to the place of pollution. Nations must cooperate to solve the problem properly.


Eutrophication
Plants need nutrients to get growing; nitrogen (N) and phosphorus (P) are two important nutrients. These are often given to agriculturally grown plants in the purpose of making plants grow faster and bigger. But when these chemical nutrients end up in watercourses of any kind; lakes, rivers or coastlines; they proceed nourishing the aquatic vegetation as well. That is called eutrophication.

Watercourses affected by eutrophication are encumbered with inordinate growth of rooted plants and floating algal scum. The amount of bacterial life depends to the amount of algae; accordingly an increase of algae means an increase of bacterial life. Bacterial life consumes oxygen (O) and therefore a large amount of bacterial life might cause a lack of oxygen in affected watercourses.

Eutrophication is considered to be the largest threat against the marine environment. Coastlines that rivers polluted by nutrients flows into are the most troubled areas; so called ‘dead zones’ are to be found in Gulf of Mexico, the Sea of Marmara and the Baltic Sea.

Renewable energy sources

Water and wind energy
Water and wind are, by nature, always in move. They accordingly store a large amount of kinetic energy available for us to transform into electric energy. Energy from water and wind is renewable and doesn’t produce any water or air pollution, in other words, water and wind energy is friendly to the environment.

Water energy, also called hydropower, extracts the energy out of falling or flowing water. To describe it concisely, a hydropower plant has got so called penstocks, pipes, to lead the flowing water to the turbines, which spin the electricity-producing generators.
Hydropower plants don’t harm the global environment but they might harm the local by affecting habitats of aquatic creatures. Especially salmons are troubled as they use to swim upstream to reproduce, and for them the hydropower plants are obstacles in their way. On some places the problem has been solved by the construction of ‘fish ladders’ that help salmons get trough the plants.

Wind energy is quite simply extracted out of machines that work in the same way as old-fashioned windmills, with blades which the wind gets in move. The blades are connected to a generator in which the electricity is produced. Wind machines are to be found in different sizes, where the largest one in the world has got blades in the length of a football field.
Wind machines are criticized for being noisy and for destroying pleasant views, as they have to be built in windy places, which often means open, untouched nature. In some places they also have a negative impact on bird populations as birds tend to fly into the wind machine’s blades.

Unlike the water energy which can be extracted in a quite steady stream, the amount of available wind energy depends to whether the wind is blowing or not. Therefore wind and water energy are often combined with each other to cover the demands for electric energy.


District heating
With the right technology, heat can be extracted from many sources. For example heat is released when burning municipal waste, in industries or in power plants of different kinds. Heat is also to be found beneath the Earth’s surface; that is called geothermal heating.
District heating is the technology of utilizing these different kinds of ‘spare’ heat. The heat is distributed to customers by a network of insulated pipes, in which the heat is transported usually by water, but more seldom also steam.

In the Nordic countries, especially Iceland, district heating is a very common way of heating, not to forget the former Soviet countries, in which district heating provides 30-70% of the heat market.
Compared to localized boilers, district heating offers better efficiency and, accordingly, better pollution control, but the environmental impacts of district heating systems depend a lot to which source of heat is used.


Biofuels
The photosynthesis of plants is a part of the carbon cycle, where its task is to absorb carbon dioxide from the atmosphere, keep carbon as ‘materials’ and emit oxygen. Thus, when a plant is burned, only the carbon dioxide that recently belonged in the atmosphere is emitted.
Fossil fuels, on the contrary, imply a surplus of carbon and when they are burned, the polluting kind of carbon dioxide is emitted as a part of the global warming.
This is the reason why biofuels; fuels made of biomass, for example sugars; affect the environment less than fossil fuels. They are also, unlike the fossil fuels, a renewable energy source as biomass can be grown anew again and again.
To make ethanol, a common type of biofuels, biomass high in carbohydrates is fermented quite in the same way as production of beer; although biofuels are made undrinkable. The result is a liquid fuel that is an alternative to conventional fuels like petrol and diesel.

There is a debate, called the food or fuel-debate, where critics consider the production of biofuels to increase the prices of food. Some scientists also say that the amount of energy needed for production of biofuels is larger than the amount of energy they give.
But the politicians seem sure about the biofuels as a substitute for fossil fuels. The European Union aims to replace 5,75% of the diesel and petrol used for transportation with biofuels by the year of 2010, and 10% by 2020.

Heat pumps
A heat pump works in order to transport heat from a source, which can be the ground, a lake or the air, to a sink; the building the heat pump serves. The source can also be spare heat from the building itself.
As a heat pump does not produce the heat, only absorbs it and transports it, heat pumps can be considered as more environmental friendly than many other kinds of heating systems. Their environmental impacts depend, though, on the source from which the electricity is delivered.

Life cycle analysis: paper
All products manufactured by humans affect the environment more or less in a negative way. Production and transportation need raw materials and energy, and in the end of product’s life it’ll be disposed as refuse and burden the earth with the toxins the product probably contains and with carbon dioxide when the refuse is burnt. When recycling products, the demand for new ones to be produced is decreased and the products’ disposal as refuse is delayed.
A life cycle analysis follows a certain product from the cradle to the grave. This is a general life cycle analysis of paper products.

• Trees are chopped down and transported to a paper mill where a so-called ‘chipper’ turns it into small pieces, ready for the next step of the production.

• The pieces of wood are mixed and boiled with water and chemicals to become pulp, a more or less fluid mass bleached with chemicals to remove its grey tinge.


• The pulp, in a mixture where 99% is water, is sprayed onto a mesh screen, flattened and dried.

• In the final step of the production, the paper is cut into pieces of the proper size. The pieces are transported away to be sold or to be printed on.

• Products are used by customers. If they also get recycled, they’ll return the pulp stage and come back as new paper.

• In case the product isn’t recycled, it’ll simply end up in the trash. Sooner or later, the product will be burnt and let out in the atmosphere as carbon dioxide and different kinds of gases depending to which chemicals were used in the production of the paper.

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