Which of the Following Was Probably the MOST Significant Event

question 6

Multiple Choice

Which of the following was probably the MOST significant event in 1999 to impact the environment?

• A)The Kyoto Protocol was signed by the United States.
• B)The Exxon Valdez created the world's largest oil spill.
• C)World human population reached 6 billion individuals.
• D)The first Earth Day celebration was held.

---

Definitions:

National Ambient Air Quality Standards

Regulations established by the Environmental Protection Agency (EPA) to control air pollution by setting limits on the concentration of pollutants in the air.

EPA

The Environmental Protection Agency, a U.S. federal agency responsible for protecting human and environmental health.

Implementation Costs

Expenses associated with putting a plan, policy, or system into operation, including the costs of acquiring necessary materials, technology, and training.

Massachusetts v. EPA

A landmark Supreme Court case in which Massachusetts sued the Environmental Protection Agency for failing to regulate carbon dioxide and other greenhouse gases as pollutants.