Human Impact on the Environment — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A town's population doubles in 20 years. Which is the MOST likely effect on energy use and air quality?
A) Energy use rises and air pollution increases
B) Energy use drops because more people share
C) Air quality improves with more people
D) No change occurs in either factor
Population growth raises energy demand, which often increases emissions.
2. A city replaces 50% of its coal plants with wind turbines. What outcome is MOST expected over time?
A) More smog and acid rain
B) Less air pollution and lower greenhouse gases
C) Higher fossil fuel use
D) More mining waste
Switching from coal to wind reduces smoke, gases, and warming pollution.
3. A farmer sprays heavy pesticides near a stream. Which result is MOST likely downstream?
A) Fish populations grow rapidly
B) Water becomes safer for drinking
C) Chemicals harm aquatic life and water quality
D) Stream temperature drops significantly
Pesticide runoff poisons fish, insects, and people who use the water.
4. A school launches a recycling and composting program. After one year, the MOST likely outcome is:
A) More garbage sent to landfills
B) Higher energy bills for the school
C) Fewer trees planted nearby
D) Less waste sent to landfills and richer soil from compost
These programs cut landfill use and turn food scraps into useful soil.
Part B: Fill in the Blank
Write the correct answer on each line.
1. Burning fossil fuels releases carbon dioxide, a major greenhouse gas.
Greenhouse gases hold heat and warm Earth's climate over time.
2. Long-term changes in Earth's average weather are called climate change.
Climate change affects sea levels, storms, and where species can live.
3. Acid rain forms when smoke gases mix with water in the atmosphere.
Acid rain damages forests, lakes, and even stone buildings.
4. When too many fish are caught, the population can collapse.
Overfishing prevents fish from reproducing fast enough to recover.
5. Rules or laws made to protect nature are called environmental policies.
Policies set limits on pollution and protect parks and species.