Otázka: Nature and the Environment
Jazyk: Angličtina
Přidal(a): Alice Hanke
The environment means surroundings in which people, animals and plants develop and exist. The branch of biology investigating relationships between living beings and their environment is called ecology. Science reflects the concern about the balance of nature. Ecologists and environmentalists are very well aware of the bad state of the environment and the necessity of its protection.
The human environment is being destroyed by activities of people. Environmental problems affect all countries of the World. It is generally acknowledged that pollution is one of the greatest problems of our age. We have polluted practically the whole planet.
The most serious ecological problems of today are:
- Air pollution an acid rain
- Changes in the atmosphere´s and ozone layer
- Global warming, greenhouse effect
- Destruction of forests
- Recycling
- Pollution of seas and oceans
- Endangered animals
- Extinction of certain species
- Natural disasters
Air Pollution
Air pollution is the biggest problem in large cities and areas with concentrated industrial productin. Emissions range from smoke, dust and car exhausts. Coal-fired power stations and industrial plants burning fossil fuels cause these emissions. The Gases as sulphur dioxide, nitrogen oxide and carbon dioxide react with water vapour in the atmosphere and form sulphuric acid and nitric acid. Sunlight turns these acids into poisonous oxidants which fall in the form of acid rain, mist or snow onto trees and gradually kill them.
Acid rain is killing large parts of forests in North America. Many forests in central and northern Europe, including the Czech Republic, are also affected. These affected trees lose leaves or needles, have deformed growth and often die.
Lakes and streams have also become acidified. The pH of water changes, and fish, insects and other wildlife cannot live there. This problem is widespread in Scandinavia and North America.
Greenhouse effect, global warming
The natural GE
Greenhouse gases act like a blanket around our planet which traps in heat, making the temperature rise.This is called the GE and is a natural process that keeps the planet warm and sustains life. If the GE didn´t exist, the average temperature on earth would be around -18°C.
BUT!
Manmade atmospheric emissions, such as carbon dioxide (fossil fuels), nitrogen oxides (car exhausts), CFCs, methan and water vapour prevent the heat from escaping. The result is a rise in the Earth´s temperature, the melting of arctic ice and flooding of areas situated near sea level.
The Ozone Layer
The good ozone layer is a thin area in the stratosphere high above the Earth´s atmosphere. It protects the earth from the sun´s destructive ultraviolet rays. This protective layer is being damaged by chemicals known as chlorofluorocarbons which are released into the atmosphere by daily products. The chlorine attacks the ozone molecules which creates holes in the layer. This hole allowes more UV rays to get to the earth´s surface.
Overexposure to UV rays can increase the risk of skin cancer, weaken the immune system, and damage the retina. But not only humans are at risk. Animals, plants, and the environment in general are also affected by UV rays. These rays can penetrate the oceans as 3 well and can seriously affect the growth of plankton, an assential part of the marine food chain. If there isn´t enough plankton, fish populations will be lower and that means less food for the world. UV rays also have an effect on important crops such as soybeans, cotton and rice.
The ozone layer serves as the planet´s cooling system.It is predicted that even a small increase in average temperatures will cause fertile areas to become deserts and polar ice to melt, raising the sea level and flooding many costal areas.
The bad ozone layer at lower atmosferic levels. It is produced by the reaction of sunlight on car exhaust fumes and it is a major air polutant in hot summers. On the ground level ozone can cause asthma attacks, corrosion of certain materials and stunted growth of plants.
Alternative sources of energy
Smoke from coal fires which causes smog, also represents a considerable problem in large cities and threatens life. How can the problem be solved? First of all, people should try to use alternative sources of energy:
- solar
- water
- wind
- geothermal
- tidal
- burn smokeless fuels
- high – efficiency gas-fired plants,
- nuclear plants
- energy from landfill waste sites
Air pollution caused by road traffic
Solution:
- To switch freight from road to railway
- To support public transportation
- To drive at the speed limit in order to use fuel more efficiently
- To encourage tree planting (trees absorb carbon dioxide)
The Forests
Trees are vitally important for our life because they are the lungs of our planet. They absorbe carbon dioxide from the air and give out oxygen in return. If we lose tropical forests, it will become more difficult, perhaps even impossible, to breathe. Another essential effect is global warming. What is more:
- The tropical rain forests in Amazonia, west and central Africa, and southeast Asia are the home of half the earth´s living things
- Forests provide many different kinds of food, medicine and other natural products
- They help determine rainfall, temperature and other climatic conditions
If nothing is done about it, they will have nearly disappeared in twenty years. The effect on world´s climate, agriculture and food supplies will be disastrous.
Soil pollution, Recycling
Soil can be contaminated as a result of industrial waste. One of the main solutions of this problem is recycling
- Bottle, can, paper and plastic containers should be installed
- Domestic rubbish should be sorted out
- Kitchen garbage and garden waste of organic origin can be composted
- Organic waste in landfills can be re-used in the form of biogas
- Used materials should be remanufactured into new products:
Land can also be contaminated by radioactive substances. Strict controls should be placed over the storage , use and disposal of radioactive substances. The storage of spent nuclear fuel is being discussed, but generally such waste has to be stored in concrete blocks for at least 50 years.
Endangered Species in the Oceans
The seas are being filled with poison, industrial and nuclear waste, chemical fertilisers and pesticides, and sewage. The latest disaster happened in the Gulf of Mexico (oil rafinery cash and offshore oil spills).
Extinction
Every ten minutes one kind of animals, plants or insects dies out forever. We say it is extinct. Extinction can be a natural process – e. g. Dinosaurs died out naturally, but all the dodo birds of Mauritius were killed by humans, so they were extinct. In today´s world the extinction happens much faster than before. If nothing is done about it, one million species that are alive today will have become extinct twenty years from now.
- The dolphin population (In the past 30 years the tuna – fishing industry has killed more than 6 million dolphins. They get caugth in the drift-nets used to catch tuna.)
- Seals are beaten to death to provide fur coats.
- Turtles are killed for their meat, shell and oil. Walruses for their ivory.
- Crocodiles to make handbags and shoes.
- Many elephants are killed for their ivory tusks
- Rhinos are killed for their horns.
If the species are not protected, they will become extinct. Fortunately, somebody is trying to do something about it. In 1961, a large international organization called the World Wildlife Fund was founded. This organization has raised big sums of money for conservation projects and has helped a lot of mammals and birds to survive.
REMEBER – Remedies will not only be achieved by the important decisions of politicians but also by our everyday behavior.
