Sustainability

b. pesticides

a. coal

Atmospheric carbon dioxide concentrations are expected to increase, because practices that are responsible for carbon emissions are expected to increase. With an increased demand for energy caused by an increasing population, fossil fuel burning is expected to increase. When fossil fuels burn, carbon dioxide is released into the atmosphere. Additionally, the clearing of forests for agriculture and living space that occurs in response to increasing populations causes a release of carbon dioxide into the atmosphere.

Increased human population not only increases the demand for freshwater, but also increases the risk of contamination of freshwater sources. As more people use a greater number of natural resources, the damage to the environment increases. With more freshwater sources being subject to pollution and an increased demand, water shortages are expected.

d. 9 billion

c. conservation tillage

Wind, solar, and biomass energy are all forms of renewable energy. Wind and solar energy use do not deplete a natural resource as is the case with coal and oil use. Using renewable resources is a sustainable practice, because it allows for continued energy use. Coal and oil reserves will eventually be depleted beyond the energy demands of the population because they are nonrenewable resources. Wind, solar, and biomass energy, on the other hand, can meet current energy needs and continue to meet the energy needs of the future.

Environmental sustainability is achieved when the environment can meet the needs of a population without losing its ability to meet future needs. Recycling practices can lead to environmental sustainability, because they help reduce the amount of waste introduced into the environment, which leads to higher pollution levels and other environmental concerns. Recycling also reduces the amount of raw materials that are taken from the environment to produce new products.

b. 2 out of 3

d. all of the above

c. It is projected to increase steadily.

True

True

True

a. erosion

b. renewable energy sources

b. increased surface water levels

c. water pollution

a. Recycling materials helps decrease the amount of new materials taken from the environment.

c. increased water storage