Olympiad Test Level 1: Environmental Issues - Class 6 MCQ

In 1994, the General Assembly proclaimed 16 September as the International Day for the Preservation of the Ozone Layer, commemorating the date in 1987 on which the Montreal Protocol on Substances that Deplete the Ozone Layer was signed.

Soil erosion is washing away or blowing away the top layer of the soil. Plants in the forests are big and are present near to each other. During rain or wind, forest plants prevent the top layer of soil to be cleared. These plants keep the soil intact within their roots and do not let it blow or be washed away. But when such plants are cleared, nothing stops the wind or water to blow away or wash away the top soil layer. This leads to soil erosion.

People all across the globe use these energy sources to generate electricity for homes, businesses, factories, and schools. We use this energy for light bulbs, run computers, refrigerators, washing machines, air conditioners, etc. We use energy to run our cars and trucks. Both the gasoline used in our cars and the diesel fuel used in our trucks are made from oil. Since renewable sources are not used on a much wider scale and the use of Non-renewable sources causes pollution to the environment and may extinct if used in a hazardous manner, so the need of the hour is to conserve these resources and use them in an efficient manner to minimize the wastage and making this planet a better place to live in.

Breathing in air pollutants can irritate your airways and may cause shortness of breath, coughing, wheezing, asthma episodes, and chest pain. Exposure to air pollution puts you at risk for lung cancer, heart attacks, stroke, and in extreme cases, premature death.

• A greenhouse gas is a gas that produces heat in the atmosphere as it increases. It also gets stuck in the environment and can not leave the internal layer of the Earth’s atmosphere. These gases introduce pollution because they contaminate the environment.
• Examples of greenhouse gases: Carbon dioxides, Methane, Chlorofluorocarbon, sulphur dioxide. Whereas, oxygen, nitrogen, and argon are not examples of greenhouse gases. Hydrogen is an indirect greenhouse gas.

Global warming is associated with the greenhouse effect that is produced when the Earth's surface and atmosphere absorb solar energy and reradiates the energy back into space. A portion of the absorbed energy is emitted by land and oceans, absorbed by the Earth's atmosphere, and reradiated back to the Earth.

A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.

Global warming is defined as the average increase of Earth's temperature due to natural as well as human-induced reasons. Global warming increases the average temperature of the Earth resulting in the melting of ice caps.

• World Water Day is celebrated on 22nd March every year to focus attention on the importance of freshwater and to advocate for the sustainable management of freshwater resources.
• The United Nations General Assembly initiated this response on 22 March 1993 as the first World Water Day.

Human activity is a major cause of air pollution, especially in large cities. Human air pollution is caused by things such as factories, power plants, cars, airplanes, chemicals, fumes from spray cans, and methane gas from landfills. One of the ways that humans cause the most air pollution is by burning fossil fuels.