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Chapter 10 – Assessing and Responding to Climate Change 10.1 – Climate Models and Clean Energy
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Uncertainties in Predicting Future Climate There are many variables that affect our climate system: ▫The carbon and water cycles ▫Concentrations of GHG’s in the atmosphere ▫Positive and negative feedback loops ▫The albedo effect ▫Ocean currents The problem for scientists is that there are too many variable to study in order to accurately predict how Earth’s climate will respond to changes in GHG concentrations
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E.g. Arctic sea ice is melting faster than the climate models predicted This means the Earth’s climate system might be more sensitive to GHG emissions than previously thought E.g. The rate at which the ocean and living things are absorbing carbon is slower than previously thought This means that the concentration of atmospheric CO 2 may increase faster than we expect, even if emissions remain constant
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Our Choice The main reason that scientists have difficulty in predicting climate changes is because they cannot predict what choices people make E.g. If we continue to use fossil fuels at the same rate, we can expect our climate to change drastically. However, if we switch to clean energy sources that produce few or no greenhouse gases, Earth’s climate may change less dramatically
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Climate Projections A climate projection is a scientific estimate of future climate conditions They are based on simulations by complete computer models (climate models) These models consider future changes that will affect GHG production
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Developing Future Climate Models Scientists need to consider the following: ▫How fast will the world’s population increase? ▫What kinds of technologies will we be using in 10 years? 50 years? 100 years? ▫What energy sources will we use in 10, 50 or 100 years?
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▫Scientists have developed projections for many scenarios ▫Scenarios that show higher GHG emissions (scenario A) result in larger temperature increases than scenarios with lower emissions ▫Under high emissions scenarios, the temperature changes by the end of the century are double those expected under a lower emissions scenario (scenario B)
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Changing Our Energy Sources
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Long-Term Effects Even if we stopped all use of fossil fuels today, climate change would not stop entirely Earth would continue to warm over the next century because of the GHG’s that have already been added to the atmosphere If we don’t stop adding GHG’s, we are likely to see severe consequences, including: ▫The complete elimination of the Greenland and Antarctic ice sheets – raise sea levels up to 15 m ▫The extinction of up to half of the world’s species ▫Increases in extreme weather events such as heat waves, floods, and droughts
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10.2 – Global Impacts of Climate Change
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Expected Changes Due to Climate In order to evaluate the risks of human-caused climate change, the Intergovernmental Panel on Climate Change (IPCC) was formed To achieve this, several thousand scientists voluntarily share and synthesize their work to come up with current projected models for climate change There are some scientists, however, that disagree with the IPCC reports, saying that they do not capture the full severity of the impacts of climate change Some scientists even suggest that most of the impacts of climate change will be less severe than predicted – and maybe even positive!!
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Main Global Impacts of Climate Change The IPCC has identified four main global impacts from climate change: ▫Rising Sea Level ▫Impacts on Agriculture ▫Impacts on Ecosystems ▫Impacts on Human, Plant, and Animal Health
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Rising Sea Level Glaciers and ice sheets melt and the oceans warm up and expand, causing the sea level in the oceans to rise Low-lying coastal areas will be at increased risk of flooding Climate change refugees Abdul’s story
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Impacts on Agriculture Dry regions, like Africa, may get even less rainfall than they are currently experiencing Crops may be less productive, leading to widespread famine Other areas, like the U.S. and Japan, could experience more rainfall, and consequently, flooding Warm and wet weather also leads to damage from insects and other pests
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Impacts on Ecosystems Some plants and animals are likely to migrate towards the poles as habitats become unsuitable Biodiversity will be lost Changes in one population could have repercussions throughout the food web
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Impacts on Human, Plant, and Animal Health Pests, diseases, and disease carriers that inhabit warmer climates could spread toward the poles This includes human diseases, such as malaria and dengue fever (transmitted by mosquitoes)
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Continental Changes
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Concern for the Canadian Arctic Climate change has been observed to be happening more rapidly in the Arctic than anywhere else in the world Sea ice is melting, causing habitats to change ▫E.g. Polar bears cannot reach their food without ice (ringed seals live on the ice) ▫People who live in the Arctic and hunt for food will be affected by changes in animal populations
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Benefits of Arctic Climate Change? Less sea ice means it is easier for ships to reach the Arctic and the valuable natural resources that exist there Trees are beginning to grow in the Arctic, helping to absorb CO 2 from the atmosphere This may make it possible for farmers to grow food at higher latitudes However, this can also reduce the albedo of the tundra, resulting in a net increase in warming!
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How Does This Affect the World? Albedo effect ▫ocean and land will reflect less of the sun’s energy Release of CO2 ▫Permafrost may contain more stored CO2 and CH4, and if released, will enhance the GH effect Sea level rise Ocean currents ▫Fresh water flowing into the ocean from melting ice will slow or stop ocean currents that transport thermal energy around the globe Biodiversity Changes in shipping and transportation
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Geoengineering (see pg. 418) Geoengineering is the use of technology to modify Earth’s environment 1.Mirrors in Space -Mirrors could be used to reflect some of the Sun’s radiation back into space -This would take 55 000 mirrors, each 100 km 2 in size! 2.Fertilizing the Oceans - Adding fertilizers to the oceans enhances the growth of algae, who would capture the CO2 in the atmosphere and store it 3.Farming Algae - Bags, vats, or tubes of algae can be used to absorb the CO2 produced by power plants and other factories - The algae can then be processed into fuel
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10.3 – Impacts of Climate Change on Ontario
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Temperature and Precipitation Winters will become warmer, with fewer extremely cold days and less snow Heating costs may go down, and there will be less ice on the Great Lakes, leading to longer shipping seasons However, there are likely to be more negative than positive changes! ▫E.g. More hot and humid summer days, leading to heat waves and adverse health effects There will likely be more rainfall, but some areas will be extremely dry, while others extremely wet
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Changing Lake Levels The water levels in the Great Lakes are dropping significantly – it is suspected that this is due to climate change! Higher temperatures mean that there is less ice cover, and more water evaporates Warmer lake waters will affect fish that live in deep, cold water environments Algae will grow faster, and invasive species may increase in numbers
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Ecosystems Some tundra plants are flowering earlier and reproducing faster Plants and animals from the U.S. could move further north, causing a disruption for existing ecosystems
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Disease and Illness Disease carrying organisms may increase as average temperatures rise and precipitation patterns change The risk of West Nile and Lyme disease increases Worsening heat waves are likely to increase heat-related illnesses and death
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Agriculture Spring will come earlier, and the growing season for crops and other plants would lengthen This sometimes encourages the growth of unwanted plants Farmers may need to use more herbicides than they do now Increases in smog will also damage crops
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Forests Summers are expected to be warmer and drier, causing more forest fires Insect populations will move north, attacking the southern parts of the forest If the forest becomes unhealthy, it can become a carbon source rather than a carbon sink
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Electricity Use As summers get hotter, we use more electricity for air conditioning This requires more energy to be generated from coal or natural gas, producing additional GHG’s Hydroelectricity will not be available if water levels in lakes drop significantly
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10.4 – Taking Action to Limit Climate Change
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How Quickly Do We Reduce GHG’s? Scientists suggest that we should limit the overall temperature increase to 2°C in order to avoid most of the dangerous impacts of climate change It is suggested that we need to limit CO 2 output to no more than 450 ppm To do this by 2050, we would need to cut GHG emissions by 80% Our provincial government has made this commitment, but the federal government has not!
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The Canadian Government Perspective The Canadian government is working with many countries around the world to reduce GHG emissions In 2002, Canada agreed to join the Kyoto Protocol, an international treaty designed to set short term goals for limiting GHG’s Under this agreement, industrialized countries are required to reduce their emissions by 2012
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The Kyoto Protocol About 70% of people originally supported the Kyoto Protocol, however, the government of Alberta was specifically vocal about the thousands of jobs that would be lost in the fossil fuel industry In 2006, our PM announced that we would not meet our Kyoto targets by 2012 The international community is now criticizing Canada for not living up to our Kyoto commitments In June 2008, the opposition parties in the Canadian government passed legislation (opposed by the minority government) requiring Canada to cut GH emissions by 80% by 2050 New legislation has not yet been implemented
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Provincial and Municipal Governments and Climate Change The Ontario government introduced Go Green: Ontario’s Action Plan on Climate Change in August 2007 The action plan includes the following: ▫Shutting down 4 remaining coal-fired generating stations by 2014 ▫Reduce GHG emissions by 6% by 2014, 15% by 2020, and 80% by 2050 ▫More public transit ▫Support green technologies ▫Planting 50 million trees in southern Ontario by 2020 ▫Working with leading scientists to implement recommendations for adapting to climate change ▫Legislation to fast-track approval of renewable energy projects like wind turbines
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Businesses, Industries, and Government – what can they do?? Transportation ▫Drive more fuel efficient cars (hybrid, electric) ▫Use environmentally friendly fuels Producing energy ▫Implement new technologies ▫Clean energy like wind and solar Industries ▫More efficient equipment will consume less energy ▫Recycle energy (capture thermal energy and use it to power other processes) ▫Impose taxes and limits on fossil fuel use ▫Capture and store carbon dioxide released by smokestacks Building and contracting ▫Increase energy efficiency ▫Install better insulation ▫Rebates and tax incentives for insulating and energy efficiency
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Businesses, Industries, and Government – what can they do?? Agriculture ▫Restore polluted land so it can re-absorb carbon (ie. Plant native plants) ▫Implement ways to reduce methane emissions in rice and cattle farming ▫Use less nitrogen fertilizers Waste management ▫Collect methane from landfills and use as an energy source ▫Compost organic waste ▫Reduce volume of waste generated & recycle Forests ▫Plant more trees to replace trees that are cut down ▫Reduce deforestation ▫Produce and use fuels from waste forestry products (biofuel) instead of fossil fuels
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10.5 – What Can Individuals Do?
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Reducing Your Emissions More than 1/3 of Canada’s greenhouse gas emissions come from the activities of individuals Most of the greenhouse gas emissions come from transportation and home heating/cooling There are many things you can do to reduce emissions, including: ▫Walk, bike, take public transit, carpool ▫Choose fuel efficient cars ▫Turn off lights and unplug unused appliances ▫Take less airplane flights ▫Use air conditioners only when necessary ▫Plant trees native to your area ▫Turn off running water ▫And more!!!!
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Carbon Offset Credits Environmentalists suggest that it is impossible to reduce our GHG emissions to zero However, we can achieve “carbon neutrality” by purchasing carbon offset credits By purchasing credits in clean energy programs like wind farms and solar power, we reduce the burning of fossil fuels, and therefore offset CO 2 emissions There is some criticism of this program: ▫They suggest we are easing the conscience of rich countries and allows them to continue their current lifestyle of using fossil fuels
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Climate Change and Stewardship Stewardship means the careful management of something that one does not own We now understand that the Earth does not belong to us; we are simply its caretakers! Ultimately, the value we place on our planet identifies our responsibility to care for it in the long term Some reasons why we should be stewards of the Earth include: ▫To protect human health ▫To save money ▫To improve our city/town ▫To protect traditional activities ▫To protect the environment
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