SECTION 1

1. Air Pollution. Composition of Air. Causes of Air pollution. Combating go air pollution.

Air Pollution. Composition of Air.

The atmosphere of Earth is the layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, greenhouse effect, reducing temperature extremes between day and night.

Air is mainly composed of nitrogen, oxygen, and argon, which together constitute the major gases of the atmosphere. Water vapor accounts for roughly 0.25% of the atmosphere by mass. The remaining gases are often referred to as trace gases, among which are the greenhouse gases such as carbon dioxide, methane, nitrous oxide, and ozone.

Causes of Air pollution.

Air pollution is most common in large cities where emissions from many different sources are concentrated. 

Air pollution consists of chemicals or particles in the air that can harm the health of humans, animals, and plants. It also damages buildings. Pollutants in the air take many forms: gases, solid particles, or liquid droplets.

Pollution enters the Earth's atmosphere in many different ways. Most air pollution is created by people, taking the form of emissions from factories, cars, planes, or aerosol cans. Second-hand cigarette smoke is also considered air pollution. These man-made sources of pollution are calledanthropogenic sources. Some types of air pollution, such as smoke from wildfires or ash from volcanoes, occur naturally. These are callednatural sources. Air pollution is usually thought of as smoke from large factories or exhaust from vehicles. But there are many types of indoor air pollution as well: by burning substances such as kerosene, wood, and coal, naturally-occurring radon gas, a cancer-causing material,construction materials, including insulation, ventilation, air movement, toxic mold. Ways to Reduce Air Pollution.

We make choices everyday that can help reduce air pollution.

1. Conserve energy - turn off appliances and lights when you leave the room.

2. Recycle paper, plastic, glass bottles, cardboard, and aluminum cans.

(This conserves energy and reduces production emissions.)

3. Plant deciduous trees in locations around your home to provide shade in the summer, but to allow light in the winter.

4. Choose not to smoke in your home, especially if you have children. If you or your visitors must smoke, then smoke outside.

5. Wash clothes with warm or cold water instead of hot.

Plan your trips. Save gasoline and reduce air pollution.

1. When possible, use public transportation, walk, or ride a bike.

2. Use an energy-conserving (EC) grade motor oil.

For Your Health

1. Check daily air quality forecasts, which tell how clean or polluted your air is, and the associated health concerns.

3.Biodiversity. Types of Habitats.

Biodiversity

The variety of living things in a given place—whether a small stream, an extensive desert, all the forests in the world, the oceans, or the planet—is called its biodiversity

A habitat is a place were plants and animals live and provides them with food and shelter . It can be very small , such as a single tree or pound, or vast, such as a rainforest or desert . The physical conditions in a place and its vegetation are both part of the habitat.

Forests are essential for life on earth. 1.6 billion people depend ob them for their livelihoods. Forests also provide habitat for a vast array of plants and animals.

Types of habitats:

1 Oceans contain the greatest diversity of life on Earth. Humans rely on the oceans for their important natural resources. Fishing is the principal livelihood for over 200 million people/

2 Freshwater ecosystems account for less than 0.1%of the planets total surface area but they support more than 100 000 species.

3 Grasslands have many names- prairies in North America , Asian steppes , Australian rangelands. Rangelands are areas where the vegetation is dominated by grasses

4Life in the polar regions can be incredibly difficult. These regions are dominated by Earth's polar ice caps. . every month in a polar climate has an average temperature of less then 10 °C (50 °F)

5 A wetland is a place were the land is covered by water: marshes and ponds, shore of the lake or ocean…

6 Deserts are characterized by their rainfall – or rather, their lack of it. Most deserts get less then ten inches of precipitation each year and evaporation usually exceeds rainfall.

7When the tectonic plates smash into each other, they are pushing earths crust higher, forming mountains. Some mountain chains like the “Himalayas “, and are still growing.

4.Engangered Species of Flora and Fauna.

CITES - the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention is a multilateral treaty to protect endangered plants and animals. Roughly 5,000 species of animals and 29,000 species of plants are protected by CITES against over-exploitation through international trade. Each protected species or population is included in one of three lists, called Appendices. The Appendix that lists a species or population reflects the extent of the threat to it and the controls that apply to the trade. Many wild animals face common threats. For example, loss of habitat. Overfishing threatens whales and many fish species.

Now the greatest problems facing plants and animals--and people, too--are the human activities that harm the environment on which plants, humans, and other animals depend. The most dramatic effects of habitat destruction can be seen in tropical rain forests. These forests have the greatest diversity of plant and animal life. People have killed or collected animals and gathered plants for a variety of uses. Animal and plant products have been used for food, medicine and clothing.

People are also helping plants and wildlife survive. One solution to the problems is ecotourism to promote people's awareness of living animals. Programs such as this, combined with laws, awareness, and commitment, will help maintain the delicate balance of nature that is necessary for the survival of all living things.

Endangered Species:

Tiger, India | Grizzly bear | Desert tortoise | Leopard darter | Bald eagle | Wyoming toad