Part 3 The Power of a Toeprint The Channel The storm reached them and a cedar tree crashed across the narrow trail. Sara lagged behind as Odin shouted out, "We're almost there! A long-fi ngered, weathered, and calloused hand appeared over the fallen cedar. Sara assumed it belonged to someone who had joined them on the trail to reach safety. But once over the fallen tree, she only saw Odin. Odin motioned for Sara to follow him to a trail beside the Chinook River. As the wind and rain intensifi ed, it became harder for them to stay on their feet. Sara nonetheless pushed ahead as Odin shouted, To the channel!" A shelter appeared downriver. Here they could stand on a narrow ledge with their backs to the cliff to wait out the heavy storm. Sara thought they were on the main tributary of the Chinook, not a channel. Did you mean the river? she asked. Odin was sitting a few steps away, his knees drawn up underneath his chin. "The channel, he said. It's right there." Sara saw the word "Channel in faint blue letters across a panel of weather-beaten metal embedded in the cliff. With a few quick strokes of her sleeve, the number "6" appeared alongside it. It was her van. As the storm raged, water cascaded off the cliff. "Um, can we uncover another part of the van...uh...channel." said Sara, looking up and noticing that the now rushing sheet of water was edging closer. It's kind of hard for me to explain, she said, as she faced the young man while clearing the portion of the rear doors. But this is something I used before I... I know," interrupted Odin with a smile. The side of the van emerged. Sara grabbed hold of the handle and swung the door open. The flash flood was eroding their shelter and the only option for safety was to enter the van. Sara got inside. "Okay, here we go." She turned to reach for Odin, but he was now in the distance, negotiating his way across the ledge toward the riverbank, a trail of footprints fading in the storm behind him. Just as Sara shouted for him to return, the side of the cliff gave way, crushing the door closed. She fell backwards for a time. When she finally came to rest against the van's dashboard, the glare of searchlight beams closed in. Dr. Fahrenheit, are you all right? The badge on the man's shoulder read Chinook Valley Fire Department. Back Home Sara Fahrenheit listened from behind the curtain, waiting to deliver the commencement address for Chinook Valley Col lege. She'd been heartened by the valedictorian's speechthat young lady wanted to become an educator and had prom ised to do her part in taking American students back to the top of the developed world's standings in math and sciences. Over the past few years, Sara hadn't thought much about what happened in the Chinook River, dismissing it as an odd dream. But it had inspired her to stop working as a TV meteorologist and write Global Climate Change: Best and Worst Case Scenarios by 2100. The book quickly became a bestseller. The valedictorian introduced Sara, who walked to the podium and began her address: We've all beard about global warming and climate change. Some of the information might make us feel hopeless because it can make the problem sound insurmountable. There are more than likely a few of you who believe that global warming is such a vast problem that it's hard to figure out what we can do as individuals to address it. Or you could be among those who believe it's nothing of concern, because the levels of CO, and other greenhouse gases present in the atmosphere throughout certain periods of our planet's history exceeded the levels we are experiencing today... The valedictorian started to daydream about what it would be like to teach high school. What could her students do to cut down on greenhouse emissions? She knew that as a teacher she would want her students to know that they could make a difference in the world. "Global Climate Change" by Carnell and Price Page 6 NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE Reducing our own carbon footprintseven in small wayswill result in a large reduction in the total amount of CO2 emitted. Activity To get to high school, students can get dropped off, take the bus, ride their bikes, carpool, or drive themselves. If a student can aff ord her own car and gas, why shouldn't she enjoy the convenience and privacy of driving to school every day? Facts Passenger cars in the United States contribute approximately 645 million tons of CO2 emissions into the atmosphere each year. For every gallon of gasoline burned, 19.4 lbs. of CO2 is emitted to the atmosphere. The average miles per gallon for passenger cars in the U.S. is about 22. Find your Carbon Toeprint So many resources that we use todayswitching on our computers, driving our cars, recharging our cell phones, draw on power that potentially emits more CO2. Our carbon footprint is an estimate of how much CO, we use. Let's look at what might be considered a carbon toeprint: how much CO, high school students would emit during their commute to school if they were all to drive themselves. Questions 1. Begin by using Figure 3.1 to complete Table 3.1. Record the total number of miles that each of the 25 students in Figure 3.1 would drive to and from school. 2 students 0.8 miles 1.1 miles 2 students students 0.7 miles 0.3 miles JU Tu 0.7 miles 2 students Students students 0.6 miles 9 2 students 2 students 2 students bus routes mies stops: a.k students 0.3 miles 3 students Figure 3.1. Students in this neighborhood all attend the same high school. How much CO, would be emitted if each student drove himself or herself to and from school each day? How much CO, would be saved if they all rode the bus together? "Global Climate Change" by Carnell and Price Page 7 NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE Table 3.1 Distance students would travel if they drove themselves Stop Miles to Total miles driven Numb and from by all students living er of school near that stop Students A 2 B 2 2 D 3 E 2 F 2 G 2 H 2 I 3 J 3 K 2 Average: 2. Calculate the average distance traveled each week by all students in a school district: a. Calculate the average number of miles traveled by the 25 students whose routes you studied. b. Multiply the average distance traveled to school by the number of high school students in your school district. c. Multiply that by 5 for each day of the school week. 3. Divide that number by 22 miles per gallon to calculate the average amount of fuel used throughout the week. 4. Now multiply that by 19.4 lbs of CO2 per gallon emitted into the atmosphere. 5. How many tons is that? Now let's suppose everyone takes the bus. More CO, is being emitted than if everyone were walking or riding a bike, so how much CO, would actually be saved each week? Let's assume these same 25 students ride a single bus. 6. Use Figure 3.1 to calculate the total number of miles that the bus drives to pick up and drop off students. 7. Calculate the average distance traveled each week by all students: a. Divide the number of miles that the bus drives each day by 25 to find the distance traveled per student on the bus. b. Multiply that result by the number of high school students in your school district. c. Multiply that by 5 for each day of the school week. 8. Buses use more fuel than cars, so divide that number by 7 mpg to calculate the amount of fuel used by one bus throughout the week. 9. Now multiply that by 19.4 lbs of CO2 per gallon emitted into the atmosphere. 10. How many tons is that? 11. How many tons of fuel are saved in a single school district each week if the students take the bus instead of driving? The National Renewable Energy Laboratory, a federal laboratory under the auspices of the Department of Energy, reports that a number of school districts are paving the way for reducing the carbon emissions of school buses even more. Strategies include using alternative fuels like natural gas and biodiesel. Part 3 The Power of a Toeprint The Channel The storm reached them and a cedar tree crashed across the narrow trail. Sara lagged behind as Odin shouted out, "We're almost there! A long-fi ngered, weathered, and calloused hand appeared over the fallen cedar. Sara assumed it belonged to someone who had joined them on the trail to reach safety. But once over the fallen tree, she only saw Odin. Odin motioned for Sara to follow him to a trail beside the Chinook River. As the wind and rain intensifi ed, it became harder for them to stay on their feet. Sara nonetheless pushed ahead as Odin shouted, To the channel!" A shelter appeared downriver. Here they could stand on a narrow ledge with their backs to the cliff to wait out the heavy storm. Sara thought they were on the main tributary of the Chinook, not a channel. Did you mean the river? she asked. Odin was sitting a few steps away, his knees drawn up underneath his chin. "The channel, he said. It's right there." Sara saw the word "Channel in faint blue letters across a panel of weather-beaten metal embedded in the cliff. With a few quick strokes of her sleeve, the number "6" appeared alongside it. It was her van. As the storm raged, water cascaded off the cliff. "Um, can we uncover another part of the van...uh...channel." said Sara, looking up and noticing that the now rushing sheet of water was edging closer. It's kind of hard for me to explain, she said, as she faced the young man while clearing the portion of the rear doors. But this is something I used before I... I know," interrupted Odin with a smile. The side of the van emerged. Sara grabbed hold of the handle and swung the door open. The flash flood was eroding their shelter and the only option for safety was to enter the van. Sara got inside. "Okay, here we go." She turned to reach for Odin, but he was now in the distance, negotiating his way across the ledge toward the riverbank, a trail of footprints fading in the storm behind him. Just as Sara shouted for him to return, the side of the cliff gave way, crushing the door closed. She fell backwards for a time. When she finally came to rest against the van's dashboard, the glare of searchlight beams closed in. Dr. Fahrenheit, are you all right? The badge on the man's shoulder read Chinook Valley Fire Department. Back Home Sara Fahrenheit listened from behind the curtain, waiting to deliver the commencement address for Chinook Valley Col lege. She'd been heartened by the valedictorian's speechthat young lady wanted to become an educator and had prom ised to do her part in taking American students back to the top of the developed world's standings in math and sciences. Over the past few years, Sara hadn't thought much about what happened in the Chinook River, dismissing it as an odd dream. But it had inspired her to stop working as a TV meteorologist and write Global Climate Change: Best and Worst Case Scenarios by 2100. The book quickly became a bestseller. The valedictorian introduced Sara, who walked to the podium and began her address: We've all beard about global warming and climate change. Some of the information might make us feel hopeless because it can make the problem sound insurmountable. There are more than likely a few of you who believe that global warming is such a vast problem that it's hard to figure out what we can do as individuals to address it. Or you could be among those who believe it's nothing of concern, because the levels of CO, and other greenhouse gases present in the atmosphere throughout certain periods of our planet's history exceeded the levels we are experiencing today... The valedictorian started to daydream about what it would be like to teach high school. What could her students do to cut down on greenhouse emissions? She knew that as a teacher she would want her students to know that they could make a difference in the world. "Global Climate Change" by Carnell and Price Page 6 NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE Reducing our own carbon footprintseven in small wayswill result in a large reduction in the total amount of CO2 emitted. Activity To get to high school, students can get dropped off, take the bus, ride their bikes, carpool, or drive themselves. If a student can aff ord her own car and gas, why shouldn't she enjoy the convenience and privacy of driving to school every day? Facts Passenger cars in the United States contribute approximately 645 million tons of CO2 emissions into the atmosphere each year. For every gallon of gasoline burned, 19.4 lbs. of CO2 is emitted to the atmosphere. The average miles per gallon for passenger cars in the U.S. is about 22. Find your Carbon Toeprint So many resources that we use todayswitching on our computers, driving our cars, recharging our cell phones, draw on power that potentially emits more CO2. Our carbon footprint is an estimate of how much CO, we use. Let's look at what might be considered a carbon toeprint: how much CO, high school students would emit during their commute to school if they were all to drive themselves. Questions 1. Begin by using Figure 3.1 to complete Table 3.1. Record the total number of miles that each of the 25 students in Figure 3.1 would drive to and from school. 2 students 0.8 miles 1.1 miles 2 students students 0.7 miles 0.3 miles JU Tu 0.7 miles 2 students Students students 0.6 miles 9 2 students 2 students 2 students bus routes mies stops: a.k students 0.3 miles 3 students Figure 3.1. Students in this neighborhood all attend the same high school. How much CO, would be emitted if each student drove himself or herself to and from school each day? How much CO, would be saved if they all rode the bus together? "Global Climate Change" by Carnell and Price Page 7 NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE Table 3.1 Distance students would travel if they drove themselves Stop Miles to Total miles driven Numb and from by all students living er of school near that stop Students A 2 B 2 2 D 3 E 2 F 2 G 2 H 2 I 3 J 3 K 2 Average: 2. Calculate the average distance traveled each week by all students in a school district: a. Calculate the average number of miles traveled by the 25 students whose routes you studied. b. Multiply the average distance traveled to school by the number of high school students in your school district. c. Multiply that by 5 for each day of the school week. 3. Divide that number by 22 miles per gallon to calculate the average amount of fuel used throughout the week. 4. Now multiply that by 19.4 lbs of CO2 per gallon emitted into the atmosphere. 5. How many tons is that? Now let's suppose everyone takes the bus. More CO, is being emitted than if everyone were walking or riding a bike, so how much CO, would actually be saved each week? Let's assume these same 25 students ride a single bus. 6. Use Figure 3.1 to calculate the total number of miles that the bus drives to pick up and drop off students. 7. Calculate the average distance traveled each week by all students: a. Divide the number of miles that the bus drives each day by 25 to find the distance traveled per student on the bus. b. Multiply that result by the number of high school students in your school district. c. Multiply that by 5 for each day of the school week. 8. Buses use more fuel than cars, so divide that number by 7 mpg to calculate the amount of fuel used by one bus throughout the week. 9. Now multiply that by 19.4 lbs of CO2 per gallon emitted into the atmosphere. 10. How many tons is that? 11. How many tons of fuel are saved in a single school district each week if the students take the bus instead of driving? The National Renewable Energy Laboratory, a federal laboratory under the auspices of the Department of Energy, reports that a number of school districts are paving the way for reducing the carbon emissions of school buses even more. Strategies include using alternative fuels like natural gas and biodiesel