Answer the questions as below:

I CHECK YOUR LEARNING 1. Give two reasons why it is difficult for scientists to predict 5. Clean energy sources also have their problems. For each of the exaciiy how the climate will change in the future. can following, suggest one way that it might have a negative effect 2. Describe two complexities about Earth's climate system that 0" \"13 emirnmen'f 0r 0" DBOD'B- I31\" I! result in changes happening faster than expected. [In (a) hydroelectric dams (h) nuclear power stations 3. (a) What is a clean energy source? {c} biotuel production from corn (h) Give examples of two clean energy sources that you have seen being used successfully in Ontario. m 6. Suppose your family is making a titre-year plan for switching to clean energy sources. Where will you start? What steps will you take? Create a timeline to show when you would implement the steps in your plan. a ll 4. How do climate models take human uncertainty into account? I! Climate Models and Clean Energy 10.1 Science fiction movies and books contain many interesting ideas about which human technologies and society develop will affect Earth's climate. male. How do you think human technologies and society will develop; Way of Incertainties in Predicting Future Climate nong other things, the climate system depends on the following carbon and water cycles concentrations of greenhouse gases (GHGs) in the atmosphere positive and negative feedback loops, including the ack loops, including the albedo effect ocean currents, including thermohaline circulation re how quickly Farthis climate will miss sure how quickly Earth's climate will respond to changes in greenhouse gas entrations. For example, Arctic sea ice is melting faster than the climate odels predicted. This suggests that Earth's climate system might be more o, scientists have discovered that the rate at which the ocean and living absorb carbon is slower than previously thought (Figure 2). This mear ic carbon dioxide may increase faster than Figure 2 Oceans are absorb not xpect, even if our emissions rem image system with reason up e accuracy. In fact. the mind the licting climate is difficult is that scientists do not know what choices people ll make. How much the climate changes over the next 100 years depends we managetheir we continue to use fossil fucis at rces that produce few or no greenhouse tically. We have a good chance of he most severe impacts of climate change if we act soon. 10.1 Climate Models and Clean Energy Climate Projections computer models future climate based on observations me climate projection is a reasonable scientific estimate of future climate computer models. These models, called climate models, consider futur changes that will affect greenhouse gas production (Figure 3). Figure 3 This image, showing changes temperature, was generated using We do not know what our future GHG emissions will be or how quickly what Earth's future climate will probably be like under species consist To generate climate projections, scientists make assumptions about future uman behaviour. This kind of assumption is called a scenario. One scenario (A) lifferent scenario (B) is that humans switch from fossil fuels to clean energy rces within 20 years. For each scenario, scientists use climate models to make ections of how the climate would change under those circumstances. Humans use some would be about 28 6 Earth's temperature lean energy sources scianti To make climate projection mainly on fossil fuels ant carbon try the year 2100. amount of greenhouse gases that wor ps produced under each scenario. Scenario B: Finally, they input these values into Humans quickly switch HOWd BE ADOLA T G Earth's temperature would increase by climate would change under Those and also conserve energy. and of the century. year 2109. 106 Chapter 10 . Assess anding to Callm To develop future climate scenarios, scientists think about 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 years? 50 years? 100 years? higher greenhouse gas emissions result in larger temperature increases such as Scenario A, the temperature changes by the end of the century are double those expected under a lower-emissions scenario, such as Observed and Projected Warming READING TIP you are struggling to understand the help you. Abernatively, the information details to help you synthesize. Figure 5 The two coloured lines sh In Scenario A fred), humans continue (bluel. humans switch to clean energy sources and conserve energy. TRY THIS ESTIMATE ONTARIO'S FUTURE CLIMATE SKILLS: Predicting, Controling Variables, Performing, Evaluating n this activity, you will run a computer simulation and discover map produced by the program, Record your Equipment and Materials: computer with Internet access Repeat the projection for a different set of values GO TO NELSON SCIENCE Compare your results from the two sets of values. 1. Your teacher will give you instructions on accessing the . What is the greatest change that wil haccon in Or What is the least amount of change? climate value and time period you want to look at. For Which will see the least amount ofgreatest change? for the years 2071 to 2100 in Ontario. Click on your choice ow a climate model like this one can help lower greenhouse gas scenario, estimate changes in climate. am Choose a map type (l.e. province) and a location. samplesweremate model such as assumptions (if any) could be made from a climate model 10.1 Climate Models and Clean Energy 409 Changing Our Energy Sources Energy use is one of the main variables needed to generate climate devices we are accustomed to using. Extra refining, and using fo ossil fuels to using clean energy sources. The most common sources of clean energy are sun e 1 Clean Energy Sources Clean energy source ermal energy set to heat homes and other buildings. no convert it into encouraging worn the Sun ofation can also be used to heat water. roelectricity mrs turbines to counter generators that produce electricity. DID YOU KNOW? Bistues's produce greenhouse gases Biofuels use plant-based fuels to produce carbon stored in biofuels was part of so releasing & does not change me ' biofuels are considered to be carton neutral as long as fossil fuels are not plans do not emit greenhouse dis creating 410 Chapter 10 . Assessing and Responding to Climate Change Even if we stopped all use of fossil fuels today, continue to warm over the next century due to atmosphere. However, by switching from fossil fuels o clean energy sources quickly, we can prevent the onsequences include the following . the disintegration of the Greenland and West by almost 15 m and displace over a billion people extinction of up to half of the world's species, at even been identified ye . increases in extreme weather events such as heat ves, floods, and droughts celand once depended on imported coal for ng. In the past 50 years, however, Iceland has pure 6 Geotherm Charts mine ther othermal and hydroelectricity (Figure 6). How long will it take other estion will likely have a major impact on the futur DID YOU KNOW? UNIT TASK Bookmark Long summer days and cheap ow tomatoes . cumbers meas and This information about changing our energy sources might be useful as you work on the houses are heated using geothermal