What describes the greenhouse effect in relation to climate change?

• A. The greenhouse effect is a myth and has no impact on climate.
• B. Enhanced greenhouse effect from increased greenhouse gases traps more heat, contributing to climate change.
• C. Only natural variations cause climate change; human activities have no effect.
• D. The greenhouse effect cools Earth's surface.

Answer: (B)

The main idea here is that greenhouse gases act like a heat-trapping blanket around Earth. The sun warms the surface, which then gives off infrared heat; greenhouse gases in the atmosphere absorb much of that heat and send some of it back down, keeping the surface warmer than it would be otherwise. This natural warming is essential for keeping our climate hospitable. When human activities raise the levels of carbon dioxide, methane, and other greenhouse gases, that blanket becomes thicker, trapping even more heat and driving the observed changes in global climate. The other options miss this key point: the greenhouse effect is real and important for warming, climate change is influenced by human emissions, and the effect warms rather than cools the surface.