Chapter 12.2 Climate Affects Life/ Life Affects Climate (pages 445 - 448 in your text)
Deforestation • Deforestation, the clearing of trees from land, is a practice that can affect the climate of an area.
When trees are cut down: • less carbon dioxide is absorbed this can result in increased global temperature • more carbon dioxide is released from the decay of forest debris • carbon dioxide is released when forests are burned (ie. slash and burn practice to clear area for farmland)
decreased amounts of transpiration results in less cloud cover. More solar energy is absorbed and global temperature increases. • decreased amounts of transpiration results in less thermal energy being absorbed by water changing for a liquid to a gas.
Cities, Forests, Climates • Forests are very complex when considered alongside climate change. Forests have a low albedo and absorb large quantities of solar energy; leading to increased surface temperatures. Forests also absorb large quantities of CO2, leading to a decrease in global temperatures.
Cities have large amounts of concrete and small amounts of forested areas. Concrete and buildings have a low albedo and absorb large quantities of solar energy, this increases surface temperature. Cities are often called “heat islands”; their temperatures are often 10◦C higher than surrounding rural areas in the summer.
Question 1. How are large cities related to an increase in the global temperature? • Large cities have a low albedo which results in an increased surface temperature. Lack of forested areas also reduces that amount of CO2 that is absorbed and the amount of transpiration that occurs.
Chapter 12.3 How Might Biomes Change in the Future? (pages 449 - 458 in your text)
Uncertainty in predicting the future • Two major uncertainties exist in predicting global climate change in the future: 1) There is difficulty in predicting the amount of greenhouse gases that will be emitted in the future. (Reliant on development of unindustrialized nations, standard of living, human population, development of energy efficient technologies, development of renewable energy resources)
2) How will climates respond to an increase in greenhouse gases? Will it be a positive feedback (further increasing temperatures) or will it be a negative feedback (result in a decrease of temperature)?
Changes to Canadian Biomes • A projected doubling of pre-industrial CO2 levels is expected to reduce the taiga and increase the grassland and temperature deciduous forestbiomes.
Assessing the Risk • IPCC (Intergovernmental Panel on Climate Change), consisting of 2500 scientists from 70 countries, prepared a report in 2001 with the following finding: • during the 20th century the average global temperature has increased by 0.6◦C • there has been a decrease in ice and snow cover in the polar regions • sea levels have risen by 0.1-0.2 m • the heat content of the ocean has risen
Kyoto Protocol • In light of finding put forward by the IPCC a meeting took place in Kyoto, Japan in 1997 and became known as the Kyoto Protocol. • 160 countries signed the protocol • The agreement aims to reduce that amount of greenhouse gases to levels 5.2% below 1990 levels • Canada proposed a reduction target of 6%, the United States proposed a reduction of 7% • The United States “opted out” of the protocol in 2001.
An Environmental-Energy-Economic Issue • The Kyoto Protocol has received criticism for reasons such as the following: • the protocol must be continually monitored, it is not a “one time” agreement • under a “business as usual” scenario, CO2 emissions will continue to rise throughout the 20th century • participation from both industrial and developing countries is required • greenhouse gases have to be reduced by 50% over the century if climate change is to be averted.
Chapter 12.4 Human Response to Climate Change (pages 459 - 468 in your text)
Industry and transportation account for a combined total of 68% of Canada’s greenhouse gas emissions (34% each). • The transportation sector is projected to see the most growth by the year 2020
Question 2. Why is the percentage of emissions associated with transportation in Canada so high? • Canada is a large country and resources need to be transported long distances. There are a large number of large personal vehicles in Canada (related to industry and life style). Large vehicles use more fossil fuels.
Reducing Emissions • How will nations reduce their emissions of greenhouse gases? Most reductions focus on energy since a large percentage of greenhouse gases come from the production and use of energy. These reductions include: • conserving energy • improving efficiency • reducing fossil fuel usage • using alternative fuels • investing in renewable technologies
What are the Choices? • It is difficult to predict the environmental and socioeconomic consequences of climate change. As a result many people are divided in attitudes towards meeting Kyoto requirements.
The Precautionary Principle • The precautionary approach is described as follows: “In order to protect the environment, the precautionary approach shall be widely applied by states according to their capabilities. Where there are threats of serious or irreversible damage, lack of scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation”
Question 3. Re-read the precautionary approach above and put it into your own words. • In order to protect the Earth, lack of full scientific certainty will not be used as a reason to postpone measures to prevent environmental damage.
The Gaia Hypothesis • The Gaia Hypothesis is related to the “interconnectedness of life”. The Gaia Hypothesis states that: “the entire range of living matter on Earth from whales to viruses and from oaks to algae could be regarded as constituting a single living entity capable of maintaining Earth’s atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constitute parts”.
Question 4. Re-read the Gaia Hypothesis and put it into your own words. • Earth is a single living organism