1. What is "biodiversity" ?
Answer
The variety of all the different species of organisms on Earth, or within an ecosystem.
2. What is "peat" and why have peat bogs been destroyed ?
Answer
Peat is partially decayed vegetation that has been destroyed to produce garden compost, or burnt as a fuel.
3. What is "global warming" ?
Answer
The gradual increase in the Earth's average temperature.
4. Give some ways that air, land and water can be polluted by humans.
Answer
Air is polluted by smoke, acidic gases, and other substances. Land is polluted by landfills, toxic chemicals, and other waste. Water is polluted by sewage, fertilizers, toxic chemicals, and similar pollutants.
5. Describe the effect that pollution has on biodiversity.
Answer
Pollution kills plants and animals which reduces biodiversity.
6. Give some human activities that have reduced land availability.
Answer
Farming, building, quarrying, mining, dumping waste, destruction of peat bogs, etc.
7. Give some reasons why large scale deforestation has occurred in tropical areas.
Answer
To provide land for cattle, rice fields, farming, and agriculture; to grow crops for biofuels; and to provide wood for building materials.
8. Describe some possible effects of global warming.
Answer
Melting of polar ice caps and sea ice causes sea levels to rise. It leads to changes in the distribution of species. Extreme weather conditions, such as heavy rainfall leading to flooding or heatwaves leading to droughts, become more frequent. Crops may fail, posing a threat to food security.
9. Explain how increasing the proportion of greenhouse gases in the atmosphere can lead to global warming.
Answer
Greenhouse gases absorb (heat) energy that is radiated from the Earth's surface and releases this energy back to Earth, keeping the Earth warmer than it would be without the gases.