I'm working on a environmental science project and need an explanation and answer to help me learn.

Car Emissions and Global Warming

Goals & Objectives:

After completion of this activity, students will be able to:

1. calculate how much CO2 a vehicle emits;
2. describe the effect of CO2 increase in the atmosphere;
3. define greenhouse gas;
4. explain the relationship between gas mileage and CO2 emissions;
5. Identify alternative energy sources for transportation;
6. differentiate between vehicles that are high- and low-emitters of CO2;
7. evaluate the differences in mileage between developed and developing nations;
8. describe ways people, organizations, and the government can reduce emissions from cars; and
9. identify places in their daily transportation where they can reduce the emission of CO2.

Introduction:

Climate scientists agree that the presence of "greenhouse gases" (including carbon dioxide, CO2) in the earth’s atmosphere function to trap heat from the sun. There is also ample evidence that the amount of CO2 in the atmosphere has increased from 280 ppm (in 1880) to 398 ppm (in 2013), an increase of 42% (Tans and Keeling, 2013). The decade from 2001-2010 was among the hottest since temperature records have been kept (WMO 2011); the Earth has actually warmed about 1.33˚F globally. Most scientists agree that modern climate change, or global warming, is happening (Oreskes 2004; Doran and Zimmerman 2009) and research has found that increased levels of CO2 in the atmosphere play a role (Soloman et al. 2007).

The consequences of global warming are uncertain, but most scientists agree that it will profoundly affect human societies. The Intergovernmental Panel on Climate Change reports that global warming may result in severe droughts, reducing crop production necessary to feed billions of people. Rising sea levels will threaten beaches, coastal cities, and people. The migration of millions of people would strain economic, health, and social services. Conflicts over remaining resources could escalate. Wildlife habitat will be destroyed, with countless species facing extinction (Soloman et al. 2007). With the potentially devastating effects of global warming, it is reasonable and prudent to examine alternatives to fossil fuels to decrease the amount of CO2 in the atmosphere.

The transportation sector is one area that can, generally speaking, use alternative methods of fuel, since there are already a variety of alternate fuels available. Due to inefficiencies in the engine, automobiles release CO2 when burning gasoline or diesel. Despite increasing controls over emissions, the sheer number of automobiles currently on the road (there were millions of cars in the United States by the late 1980s) will negate these controls. Automobiles (including light trucks) contribute 31% of the CO2 emissions (USEPA 2013), not to mention emitting other pollutants and the environmental dangers associated with finding, extracting, and exporting petroleum. The good news is that this transition can be done relatively easily, cheaply, and painlessly.

Automobiles are at the very heart of American social and economic relations. Environmentalists cannot simply demand the elimination of the modern automobile without providing a replacement. The questions, then, become: What do people want from the automobile, and how can these services be provided without the environmental consequences of current cars?

Alternate fuels, such as propane, ethanol, and methanol can be improved and used with very little engine modification. Increased fuel efficiency (that is, getting more miles per gallon) could reduce the amount of petroleum burned and save consumers money. Finally, developing alternate fuel sources, such as electrical, solar, and hydrogen, could further reduce the need for burning fossil fuels without depriving people of their cars.

References:

An F, Gordon D, He H, Kodjak D, Rutherford D. 2007. Passenger vehicle greenhouse gas and fuel economy standards: A global update. Washington, DC: The International Council on Clean Transportation [cited 25 June 2013]. Available from: http://www.theicct.org/sites/ default/files/publications/PV_standards_2007.pdf.

Korner A, Cazzola P, Cuenot F. 2014. International comparison of light-duty vehicle fuel economy: Evolution over 8 years from 2005 to 2013. Working Paper 11. London, United Kingdom: Global Fuel Economy Initiative [cited 7 April 2016]. http://www.globalfueleconomy.org/ media/45112/wp11-iea-report-update-2014.pdf.

Doran PT, Zimmerman MK. 2009. Examining the scientific consensus on climate change. EOS Trans. AGU 90: 22-23.

Oreskes N. 2004. The scientific consensus on climate change. Science 306: 1686.

Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor MMB, Miller HL (eds.) 2007. IPCC fourth assessment report: Climate change 2007 (AR4). New York: Cambridge University Press.

Tans P, Keeling R. 2013. Trends in atmospheric carbon dioxide: Mauna Loa, Hawaii. Boulder (CO): National Oceanic and Atmospheric Administration – Earth Systems Research Laboratory, [cited 25 June 2013]. Available from: http://www.esrl.noaa.gov/gmd/ccgg/trends/.

[USEPA] United States Environmental Protection Agency. 2013. Inventory of U.S. greenhouse gas emissions and sinks: 1990-2011. Washington, DC: National Service Center for Environmental Publications.

[WMO] World Meteorological Organization. 2011. 2001-2010: A decade of climate extremes. Geneva, Switzerland: World Meteorological Organization.

Activity 1:

You will identify which vehicles you think emit the most or least amount of CO2. Look online (http://www.fueleconomy.gov/feg/findacar.htm) for vehicles to determine the amounts of CO2 these cars release. There is a direct link between gas mileage and CO2 emissions. For each gallon of gas burned, 20 lbs of CO2 is emitted!

1. Think about what factors contribute to a vehicle’s CO2 emissions. Hypothesize which characteristics you will look for in “high emitters” and “low emitters.”
2. If weather permits, walk around your neighborhood or a parking lot at a nearby store and look at vehicles. Test your hypothesis by choosing 10 vehicles you think are high emitters of CO2. Record the makes & models in Table 1. Try to estimate the model year, as well.
3. Now choose 10 vehicles you think are the lowest CO2 emitters based on your hypothesis. Write down the makes, models, and year in Table 1.
4. Use the “Fuel Economy” website above to get information on the vehicles you found.

Record the following information in Table 1:

• combined gas mileage (city and highway averaged together) for each vehicle in miles per gallon (mpg)
• “Greenhouse Gas” (GHG) Emissions from the tailpipe in grams per mile
  • After clicking on the link to the vehicle, click on the “Energy and Environment” tab and scroll down to the Greenhouse Gas Emissions information.
  • Assume that most of the GHG emissions are CO2
• Use this information to:
  • calculate the average metric tons of CO2 emitted per year for each vehicle
    • Assumption 1: The average American drives 15,000 miles each year
    • Assumption 2: There are 1,000,000 g in a metric ton
  • calculate the averages for both the high- and low-emitters, for yourself or your group.

Activity 2 – Global Fuel Economy and Carbon Emissions:

The average fuel economy of the U.S. car fleet has been improving recently but has not kept up with other countries (Figure 1). For instance, in 2006, the average gas mileage for the U.S. fleet was 24 mpg while the European average was approximately 41 mpg (An et al. 2007).

Figure 1. Average new “light duty” vehicle fuel economy by country, 2005-2013 (Korner et al. 2014). “Light duty” refers to cars and light trucks. In this figure, fuel economy refers to the amount of gas/diesel (Lge) needed to go a set distance (100 km). A lower number is better.

Activity 3 – Cars & Global warming (personal level):

From the previous activity we investigated the connection between global warming and car fuel efficiency. For every one gallon of gasoline burned, 20 pounds of CO2 is produced. Now let’s see how much CO2 we individually produce driving our vehicles. If you do not drive, base this on a friend or relative’s car. You could also calculate how much you would use if you drove instead of using public transportation.

1. Determine the number of miles you typically drive in a week.
   1. You can use Google Maps or other mapping software to estimate distances between your work, home, school, and other locations you visit on a weekly basis.
2. Determine your vehicle’s combined gas mileage using the “Fuel Economy” website from activity 1.
3. Now that you have your vehicle’s gas mileage and the average number of miles you drive per week, you can calculate the number of gallons used per week. Record it in Table 2.
4. Calculate the amount of CO2 produced in one week if burning 1 gallon of gasoline produces 20 lbs of CO2 (if your vehicle runs on diesel, it produces 22 lbs of CO2 per gallon).

Analysis Questions

Please answer the following questions in complete sentences. Answers to the questions should be done individually. Please make sure to cite your sources if necessary using the APA system.

1. What was your hypothesis about vehicles and carbon emissions? Make sure to state it in the “If…then…” format.
   1. Please explain what characteristics you looked for in your search of the parking lot or your neighborhood.

1. Compare the average CO2 emissions for the high- and low-emitters. Did there seem to be a pattern among the vehicles that you chose? What was it?

1. Using graphing software such as Excel, make a graph of your data (all 20 vehicles) comparing the following (make sure to put the information on the correct axes):
   1. The combined gas mileage (mpg)
   2. The CO2 emissions per vehicle in metric tons per year.

Add a linear trendline to your data and make sure to include an appropriate title and axis titles. Copy and paste your graph below.

1. According to your graph, is there a relationship between gas mileage and CO2 emissions? Please describe.

1. Overall, were your hypotheses supported or refuted? Why?

1. Describe circumstances in which larger or smaller vehicles are advantageous and ones in which they would not be.

1. Why do you think there are differences between the U.S. and Europe? What market factors (supply? demand? prices?) promote fuel efficiency?

1. Look at the fuel efficiency over time for India and China, two of the most rapidly industrializing countries (Figure 1). Why do you think gas mileage has not improved as greatly as other areas?

1. Other than banning cars:
   1. What would you suggest that the U.S. government do to promote fuel efficiency? Try to be as realistic as possible.
   2. What should consumers do?
   3. What should car manufacturers do?

1. Look at data Table 3. Were you surprised by how much CO2 you produce in one week? Explain.