Which statement about greenhouse gases is false?

• A. They trap heat in the atmosphere.
• B. They contribute to warming the planet.
• C. They are responsible for a global increase in average temperatures.
• D. They have no effect on climate.

Answer: (D)

Greenhouse gases trap heat in the atmosphere, which warms the planet. They are a primary driver of the recent rise in global average temperatures. These gases—carbon dioxide, methane, nitrous oxide, and others—absorb infrared radiation radiated from Earth and re-radiate it back downward, creating a warming effect. Human activities such as burning fossil fuels, deforestation, and certain industrial processes increase their concentrations, intensifying this effect and leading to higher average temperatures worldwide. The statement that they have no effect on climate is false because the greenhouse effect is a well-established mechanism showing that these gases do influence climate. The other statements correctly reflect their heat-trapping role, contributions to warming, and link to rising global temperatures.