There are two global changes that are affecting the biosphere today. One of them is *ozone layer depletion*, and the other is *global climate change*, which may also lead to *global warming*.

The ozone layer acts as a protective barrier in the atmosphere that shields us from the harmful UV radiation. Gases such as CFC cause damage (or depletes) the ozone layer. This causes the biosphere to be more exposed to harmful UV radiation.

Global climate change is the result of the greenhouse effect, which is caused by greenhouse gases that trap the heat from the sun into the atmosphere. This causes an increase in global temperatures, which results in a phenomenon known as global warming.

Ultraviolet (UV) radiation from the sun is harmful to living things. The ozone layer acts as a protective barrier in the atmosphere that can shield us from harmful UV radiation from the sun.

If the ozone layer is destroyed, humans and other organisms would be overexposed to UV radiation. This can result in damage to skin and eyes, and may even cause cancer to develop.

Hence, it is important to maintain the ozone layer by preventing the emission of gases that can damage ozone such as CFCs. This way, we can continue to be protected from UV radiation.

Many organisms are adapted to certain climates. For instance, polar bears are adapted to cold climates. The climate of a particular area can be influenced by changes in temperature.

Therefore, a worldwide increase in temperature results in global climate change. This would affect organisms globally because it severely alters the conditions of their habitats.

For example, the rise in global temperatures would cause the polar regions to melt. This change in climate would severely affect polar bears since they cannot adapt to a warm climate.

People can make wise choices in the use and conservation of resources. Avoiding using more water than necessary, planting trees, reusing or recycling wastes, and proper waste disposal are just a few examples.

During 1970s. scientists discovered the thinning ozone layer based on the evidence from the satellite images they have gathered. Due to this alarming discovery, scientists conducted a research to find out what was causing the ozone depletion in the Earth’s atmosphere. Based on the results, they found out that when the chlorofluorocarbons gases (CFCs) reach the stratosphere, it causes a chemical reaction which breakdown the ozone molecules into oxygen gases. As a result, the ozone gas is replaced with oxygen that no longer protects us against the UV rays. To resolve this environmental problem, nations around the globe signed an agreement to ban using CFCs which are found in aerosol cans and coolants in refrigerators and air conditioners.