How the Blue Ridge Mountains (Almost) Lost Their Blue

The Blue Ridge Mountains are known for their blue haze, caused by VOCs emitted by trees. These VOCs, while natural, can contribute to ground-level ozone when mixed with pollutants from fossil fuels. The region's biodiversity is due to its history as a refuge during ice ages. Pollution from coal and vehicles once reduced visibility, but the Clean Air Act has improved air quality, reducing coal use and emissions.

What is the primary reason for the Blue Ridge Mountains' biodiversity?

• Proximity to the equator

• Refuge during ice ages

• Lack of human settlement

• Rich soil composition

How do VOCs affect the appearance of the Blue Ridge Mountains?

• They scatter blue and violet light.

• They make the mountains appear green.

• They cause the mountains to look gray.

• They have no effect on the mountains' appearance.

What environmental paradox is associated with VOCs?

• They only exist in urban areas.

• They only benefit plant growth.

• They contribute to both beauty and pollution.

• They are harmless to humans.

What was a major cause of reduced visibility in the Blue Ridge Mountains during the 1990s?

• Increased tourism

• Excessive rainfall

• Natural forest fires

• Pollution from coal production

Which pollutants were primarily responsible for the haze in the Blue Ridge Mountains?

• Carbon monoxide and methane

• Nitrogen oxides and sulfur dioxide

• Lead and mercury

• Ozone and carbon dioxide

What legislation helped improve air quality in the Blue Ridge Mountains?

• The Clean Water Act

• The Endangered Species Act

• The National Environmental Policy Act

• The Clean Air Act

What energy sources have contributed to the decline of coal usage in the US?

• Biomass and geothermal

• Natural gas and renewables

• Wind and solar

• Nuclear and hydroelectric