Science Unit 3 Lesson 7

Question 1

What are fossil fuels?

Answer 1

Fossils fuels were formed from the remains of plants and animals that lived long ago. They were formed by once living organisms. When these carbon-rich fuels burn, they give off carbon dioxide as a waste gas. Carbon dioxide is a greenhouse gas that traps heat in Earth’s atmosphere

Question 2

How does coal, oil, and natural gas form?

Answer 2

Fossil fuels are the remains of plants and animals that lived and died millions of years ago. Over those millions of years, coal, oil, and natural gas formed when pressure and heat transformed those once-living organisms into fossil fuels.

Question 3

What is the main source of carbon dioxide?

Answer 3

Combustion of fossil fuels is also the main source of carbon dioxide, a greenhouse gas largely responsible for the unnatural warming of Earth’s atmosphere

Question 4

What percent of the energy we use in the US comes from fossil fuels?

Answer 4

About 80 percent of the energy we use in the United States comes from fossil fuels.

Question 5

What are the 3 main fossil fuels?

Answer 5

Coal
Oil
Natural Gas

Question 6

How does Coal form?

Answer 6

Coal is formed from plants that died in swampy forests, and were then buried by layers of sediment. Over hundreds of millions of years, heat and pressure transformed the buried plants into coal. Because coal produces more carbon dioxide and other harmful pollutants than the other major fossil fuels, there are now efforts to limits its use.

Question 7

How does oil and natrual gas form?

Answer 7

Oil and natural gas both form from the remains of tiny marine plants and animals. After they died, the organisms accumulated at the bottom of seas where sand and mud buried them. As the layers thickened on top of them, intense heat and pressure changed them into petroleum and natural gas. Oil and natural gas can form together or separately. Crude oil as it comes out of the ground is refined into many products, such as gasoline, heating oil, and diesel fuel.

Question 8

Explain Oil Shale and Tar sands?

Answer 8

Other fuels include oil shale and tar sands. They produce carbon dioxide when burned, just as other fossil fuels do. The advantage of these “other” fossil fuels is that some of the world’s largest deposits are in the U.S. and Canada. There are environmental challenges of using these fossil fuels. Extracting and processing oil shale and tar sands require large quantities of freshwater and energy and produce toxic substances.

Question 9

What are the benfits of greenhouse gases?

Answer 9

the greenhouse gases in Earth’s atmosphere keep the planet warm enough to support life. Greenhouse gases allow short-wavelength solar energy (such as visible light and ultraviolet) to pass through the atmosphere and strike Earth’s surface. The surface then re-radiates that energy at a longer-wavelength, infrared energy or heat. The greenhouse gases absorb some of this longer-wavelength energy instead of allowing it to leak out into space.

Question 10

Greenhouse gases keep the Earth’s and what temperatrue, and how would Earth’s temperature be without these gases?

Answer 10

The greenhouse gases keep the planet’s average temperature at about 15.6°C (60°F). Without these gases, Earth’s average temperature would be near freezing. The way greenhouse gases affect Earth’s temperatures is called the greenhouse effect.

Question 11

About what percentage are greenhouse gases in Earth’s atmosphere?

Answer 11

Although greenhouse gases are important, they make up less than one percent of Earth’s atmosphere. Still, they have properties that give them the ability to act as a warming blanket around the planet.

Question 12

Why doesnt water vapor have the same negative effects of Carbon dioxide?

Answer 12

Although water vapor is more abundant than carbon dioxide in the atmosphere, the amount of water vapor remains relatively consistent, so it does not change climate

Question 13

Of all greenhouse gases whichminfluences the greenhouse effect and climate change.

Answer 13

. Of all greenhouse gases, the effect of the increase of carbon dioxide in the atmosphere is the factor that most influences the greenhouse effect and influences climate change.

Question 14

What was the carbon dioxide level compared to now and the before the start of the Industrial Revolution? Is it higher than any other time in human history?

Answer 14

Just before the start of the Industrial Revolution the concentration of carbon dioxide in the air was about 280 parts per million (ppm). Today it is more than 400 ppm. Yes, this is higher than at any other time in human history.

Question 15

How and why did carbon dioxide increase so much in the atmosphere?

Answer 15

After the start of the Industrial Revolution in the mid-1700s, machines began to replace animal and human power for doing work. Most machines burned fossil fuels, especially coal. The rate at which carbon dioxide entered the air rose sharply, and is still rising.

Deforestation has also increased the atmosphere’s load of carbon dioxide. The trees in forests remove carbon dioxide from the atmosphere during photosynthesis. Loss of forests allows much of that carbon dioxide to remain in the atmosphere.

Question 16

What is the Keeling Curve?

Answer 16

The Keeling Curve is a graph was named for climatologist Charles David Keeling. Keeling set up the carbon dioxide monitoring system that produced the data in 1958. The graph shows a steady increase in atmospheric carbon dioxide between 1958 and today. Keeling’s graph has given scientists strong evidence that carbon dioxide in the atmosphere has been rising along with the increased use of fossil fuels.

Question 17

What do the yearly fluctuations of carbon dioxide levels represent?

Answer 17

The fluctuations are increases and decreases in the amount of CO2 in the atmosphere. The fluctuations are basically the same year after year, suggesting that something occurs in some seasons that decreases the level of CO2, but that event does not occur in the other seasons. During spring and summer when trees are in full leaf, they absorb carbon dioxide during photosynthesis, bringing the amount in the atmosphere down slightly. During the winter season when many trees do not have leaves and photosynthesis does not take place, the amount of CO2 spikes up slightly.

Question 18

How does Co2 affect the earth?

Answer 18

Temperature extremes and heat waves are increasingly common. Severe drought and heat have affected the Southwest. Heavy precipitation, including day-long downpours, has caused more frequent river flooding in the Northeast, Northwest, and northern Great Plains. A warmer Earth has also produced more frequent and severe storms such as hurricanes.

As warmer temperatures melt polar ice and glaciers, sea level rise has resulted. This has led to more frequent coastal flooding and the drowning of low-lying islands. A warmer ocean absorbs more carbon dioxide than a cooler ocean absorbs. When carbon dioxide dissolves in water, carbonic acid forms. Thus, the concentration of carbonic acid in the oceans has risen, threatening the survival of marine species that now find it difficult to make shells.

Climate change affects other ecosystems as well. Shorter and milder winters have affected the distribution of some species. Patterns of bird migration are shifting. Spring leaf and flower bloom dates are now earlier in the season for some species to match milder late-winter temperatures. Stream and lake temperatures have risen, changing aquatic habitats. Forests have suffered more frequent wildfires.

Question 19

How much has nitrous oxide increased?

Answer 19

Nitous oxide has increased by 50 parts per billion in the past 100 years

Question 20

How much has methane increased?

Answer 20

Methane has increased by 60 parts per billion in just the past 20 years.