Carbon, Climate, & Energy Resources Unit 4 Carbon Dioxide Production from Burning Fossil Fuels Pamela J. W. Gore, unit author

What happens when fossil fuels (like natural gas) burn? CH 4 (methane gas) + 2O 2 (gas)  CO 2(gas) + 2H 2 O (liquid) + Energy (joules) Carbon dioxide is produced Burning fossil fuels is one of the largest sources of CO 2, a greenhouse gas associated with global warming and climate change.

U.S. Greenhouse Gas Emissions (2012) Total Emissions in 2012 = 6,526 Million Metric Tons of CO 2 equivalent

U.S. Greenhouse Gas Emissions (by Economic Sector) Greenhouse gases are associated with global warming and climate change.

Sources of Carbon Dioxide The major sources of CO 2 emissions are electricity generation and transportation. Coal is the major fossil fuel used to generate electricity in the United States. The major use of coal is electricity generation. There are about 560 coal-fired power plants in the United States. Worldwide about 50,000 power plants produce CO 2. Burning coal and hydrocarbons are the largest sources of CO 2 emissions.

Byproducts of Coal Burning Carbon dioxide (a greenhouse gas, causes global warming). Sulfur dioxide (causes acid rain). Nitrogen oxide (causes smog). Carbon monoxide (poisonous gas, contributes to global warming). Small particles of toxic heavy metals. Carbon and other elements combine with oxygen and are moved from the geosphere to the atmosphere.

Which fossil fuels have the highest CO 2 emissions? Fossil fuel Weight of CO 2 (pounds) emitted per million BTU of energy Lignite lb Sub-bituminous coal lb Bituminous coal lb Anthracite coal lb Diesel fuel and heating oil Gasoline Propane Natural gas (methane) 117.0

Which fossil fuels have the lowest CO 2 emissions? Fossil fuel Weight of CO 2 (pounds) emitted per million BTU of energy Lignite lb Sub-bituminous coal lb Bituminous coal lb Anthracite coal lb Diesel fuel and heating oil Gasoline Propane Natural gas (methane) 117.0

U.S. Energy Use and CO 2 Emissions Burning petroleum products (gasoline, etc.) is the largest contributor to CO 2 emissions

Energy Use and Carbon Dioxide Emissions in the United States Fossil fuelEnergy used (%) Carbon dioxide emissions (%) Petroleum35%42% Natural Gas28%27% Coal18%32% Which fossil fuel produces the highest percentage of CO 2 emissions? Which fossil fuel produces the lowest percentage of CO 2 emissions?

The use of coal has decreased in the United States since 2008 – Why? New environmental regulations make it more costly to operate some coal plants. Some electric power producers have switched to more competitively priced natural gas. Slow growth in electricity demand. Increased use of renewable energy technologies.

Why don’t we use more natural gas for electricity generation, since it has lower CO 2 emissions? In the past, the cost of natural gas was higher than coal. In recent years the price of natural gas has dropped. As a result, there has been a surge in natural gas production from U.S. shale deposits by fracking.

Sources of U.S. electricity generation What are some alternatives to fossil fuels?

Review Questions 1.What is the primary greenhouse gas emitted in the United States through human activities? 2.What are the major sources of CO 2 emitted in the United States, by economic sector ? 3.What are the major byproducts of the burning of coal? 4.Which fossil fuel has the highest CO 2 emissions? 5. Which fossil fuel has the lowest CO 2 emissions?

Review Questions 5.Which fossil fuels are the major sources of electricity generation? 6.Why has coal use declined in recent years? 7.Which fossil fuel is the largest contributor to CO 2 emissions? 8.What could we do to reduce CO 2 emissions?