Question 1

The current primary sources of energy in the United States, in order from greatest to least, are:

Accepted Answer

According to the Energy Information Administration (EIA), as of 2020, the primary sources of energy in the United States, in order from greatest to least, are oil, natural gas, coal, nuclear, and renewables (e.g., wind, solar).

Question 2

Which of the following is true about the common practice of purifying water by adding chlorine to it?

Accepted Answer

The addition of chlorine to water can create disinfection by-products (DBPs) such as trihalomethanes which have been linked to cancer and birth defects. While it is effective in killing harmful microorganisms, it is not a guaranteed method to remove pesticide residues. In the U.S., chlorine is used for both drinking and recreational water. There is no evidence that it has health benefits such as strengthening bones and tooth enamel.

Question 3

Three of the following accurately describe industrial agricultural practices. Which one does not?

Accepted Answer

The statement "Industrial agriculture produces healthier food than was produced by pre-industrial agriculture" is not accurate. While industrial agriculture may be able to produce more food, it often relies on monoculture and the use of chemicals, which can have negative impacts on soil health and the nutritional content of the food produced. Pre-industrial agriculture often relied on diverse, sustainable practices such as crop rotation and intercropping, which may lead to healthier food with a wider range of nutrients.

Question 4

Which of the following is true about the world's topsoil supply?

Accepted Answer

Once topsoil is lost, it can only be replenished by the breakdown of more organic matter. While we may have more topsoil in some regions due to the accumulation of sediment, overall the global supply of topsoil is dwindling due to erosion and degradation. Modern agricultural practices such as monoculture, tillage, and heavy use of chemicals actually contribute to the loss of topsoil by disrupting the natural processes that build and maintain healthy soil.

Question 5

Which of the following poses a threat to healthy topsoil?

Accepted Answer

Monocultural plantings can quickly deplete the nutrients and organic matter in topsoil, making it less productive and more susceptible to erosion. Letting crop remnants and weeds decay into the topsoil and mixing compost into the topsoil can actually help replenish nutrients and organic matter, while farmers putting manure on the topsoil can contribute to the soil's fertility as long as it is managed properly.

Question 6

Given that we all have to eat, how can people reduce their food footprint?

Accepted Answer

All three choices listed (eating locally grown food, eating food that is in season, and eating minimally processed food) can reduce a person's food footprint. Eating locally grown food and food that is in season reduces the carbon emissions emitted from transportation of food, while eating minimally processed food eliminates the carbon emissions from the processing and packaging of food. Therefore, choosing all three options can have a significant impact on reducing a person's food footprint.

Question 7

What are CAFOs?

Accepted Answer

CAFOs stands for Concentrated Animal Feeding Operations, which are large scale animal agricultural facilities where animals are raised in confined areas and fed a high-calorie diet. These operations have come under criticism for their environmental impact, including high levels of waste and pollution.

Question 8

Which of the following is false about industrial meat production?

Accepted Answer

Industrial meat production is not on the decline worldwide, but rather continues to grow. This is due to increasing demand for meat and the expansion of industrialized agriculture practices in developing countries.

Question 9

Which of the following is false about the clearing of rainforests for the purpose of meat production?

Accepted Answer

Clearing rainforests for meat production often involves slash-and-burn methods, which only provide short-term soil fertility. The soil quickly loses its nutrients and becomes degraded, leading to the need for further deforestation to create new pastureland.

Question 10

Carbon sequestration refers to

Accepted Answer

Carbon sequestration refers specifically to the removal and storage of atmospheric CO2, usually through natural or artificial means such as tree planting or carbon capture and storage technologies. It is a technique used to address the issue of climate change by reducing greenhouse gas concentrations in the atmosphere.

Question 11

Meat consumption is expected to

Accepted Answer

Meat consumption is projected to increase most significantly in countries like China and India due to their growing populations and increasing wealth, which typically leads to higher meat consumption as part of a more diverse diet.

Question 12

Should people worry about what goes down their drains?

Accepted Answer

Both option A and B are correct. Much of what gets washed down the drain can end up in both drinking water supplies and bodies of water, which can be harmful to humans and wildlife. While water treatment removes many contaminants, it is not able to remove all substances, such as certain chemicals and pharmaceuticals, which can have negative impacts on human health and the environment. Therefore, it is important for individuals to be mindful of what they are putting down their drains.

Question 13

Increasing demand on freshwater supplies in the southwestern U.S. is coming from

Accepted Answer

Industrial agriculture, non-agricultural industries, and homeowners are all placing increasing demand on freshwater supplies in the southwestern U.S. This demand is leading to water scarcity issues and the need for sustainable water management practices.

Question 14

Which of the following is false regarding the world's supply of freshwater?

Accepted Answer

Option A is false because although water is a renewable resource, freshwater can still experience shortages due to overuse and pollution.

Question 15

Although it is home to less than 5% of the world's population, the U.S. consumes more than _____% of the world's supply of oil.

Accepted Answer

According to the Energy Information Administration, the U.S. consumes around 20% of the world's supply of oil.

Question 16

Which of the following is not included in estimates of energy waste in the U.S.?

Accepted Answer

While the efficiency of car engines, heating systems, and lighting systems are commonly included in estimates of energy waste, the efficiency of human behaviors related to energy use (such as leaving lights on in empty rooms or not turning off electronics when not in use) is often not taken into account.

Question 17

According to the latest estimates, about 61% of the energy consumed in the U.S. is actually wasted. This figure is most likely

Accepted Answer

The figure is likely an underestimate because energy is wasted in many ways, such as through inefficient appliances and buildings, and through transportation inefficiencies. Additionally, this statistic is generally accepted by energy experts and corroborated by various studies. It applies to the entire country, not just those in cities.

Question 18

Which of the following is true about the waste created by nuclear power plants?

Accepted Answer

The waste created by nuclear power plants is radioactive for thousands of years, hence option A is correct. Option B is incorrect as even indirect exposure to nuclear waste can be harmful. Option C is debatable as safe permanent storage techniques have not yet been implemented on a large scale. Option D is incorrect as there is no completely effective way to clean up spilled nuclear waste.

Question 19

Which of the following is false about accidents at nuclear power plants?

Accepted Answer

The International Atomic Energy Agency (IAEA) keeps a record of every accident that occurs, not the International Atomic Energy Authority.

Question 20

The majority of the world's electricity is generated by _______.

Accepted Answer

According to the International Energy Agency, as of 2019, fossil fuels (including coal, oil, and natural gas) account for approximately 63% of global electricity generation. Hydroelectricity accounts for approximately 16%, nuclear power for approximately 10%, and wind power for approximately 5%. While the use of renewable energy sources such as wind and solar is growing, they currently only make up a small fraction of global electricity generation.

Quiz 1: What on Earth Are We Doing