Study Questions: Chapter 4
1. What are the main human activities that are impacting global climate change?
Human activities causing global climate change are the burning of fossil fuels, which release CO2, water vapour, and SO2 into the atmosphere; agricultural activity, which releases CO2 from the soil; the increased use of fertilizer and animal husbandry, which adds nitrous oxide (N2O) and methane (CH4) to the atmosphere; and increased deforestation, which decreases the possibilities of absorption and storage of CO2.
2. What is the importance of the world’s tropical rainforests?
Tropical rainforests are an important contributor to the health of the global ecosystem. They are home to at least 50 per cent of all species (an estimated 15 million). They are important sources of medicine, food, fibres, and petroleum substitutes. Further, tropical rainforests store carbon dioxide, methane, and nitrous oxide, preventing the release of these harmful chemicals into the atmosphere.
3. What are the main lessons scientists learned from Easter Island?
Easter Island is thought to serve as a model of the whole planet. This microcosm of people was separated from the rest of the world allowing for overpopulation, which eventually depleted the limited resources of forests and fish. Unequipped with technology to leave the island, or the knowledge to reforest the island, this eventually led to a crash in the population.
4. What are some of the methods that are used to measure rising temperatures related to global climate change?
Satellites are being used to measure the temperature of the ocean, as these temperatures are not subject to seasonal and diurnal fluctuations. The area covered by sea ice in the Arctic, the Greenland ice sheet, and glaciers are being measured and their rate of shrinkage is another indicator of climate change. The melting of permafrost is another indicator that tracks the rise of temperatures.
5. How do we move towards a sustainable world where environmental changes are in accord with sound ecological principles?