GRADE 8 GEOG REVISION

What is the greenhouse effect?

• The warming of a planet due to trapped radiation.
• The cooling of Earth due to air pollution.
• The heating of a solid, such as a rock.

 Which of the following activities contributes the most to carbon emissions globally?

• Deforestation
• Agriculture
• Burning fossil fuels
• Respiration

Melting of glaciers and polar ice caps....

• will result in cooler temperatures in the Arctic
• will result in sea-levels rising
• Will have no effect on ecosystems
• None of the above

Which of the following gases, released by animals as a waste product of digestion, can add to global warming?

• Carbon Dioxide
• Methane
• Chlorofluorocarbon
• Nitrogen

1.  In the past, refrigerators, aerosol spray propellants and cleaning solvents were all sources of a greenhouse gas known as

• carbon dioxide
• methane
• chlorofluorocarbon (CFC)
• nitrous oxide

1.  Why is the Ozone important to life on Earth?

• A.   The Ozone reflects all the Ultra Violet radiation
• A.  The Ozone absorbs all the heat that come up from the Earth.
• The Ozone provides all the oxygen to Earth.
• The Ozone protects the Earth’ s atmosphere and the life on Earth from harmful radiant energy emitted by the sun   

Increased carbon dioxide may cause global warming by

• allowing more sunlight into the atmosphere.
• reflecting more sunlight from clouds.
• reducing the amount of oxygen in the air.   
• trapping more heat in the atmosphere.

Which of the following is the definition of water shortage? Water shortage occurs when _______________.

• level of water usage meets the water supply available
• level of water usage is below the water supply available
• level of water usage exceeds the water supply available
• level of water usage is equal to the water supply available

Which of the following has the greatest quantity of freshwater?

• Ice Caps and Glaciers
• Surface Water
• Groundwater
• None of the above

A greater population leads to greater demand for water.

• True
• False