Which gas is NOT a significant contributor to the greenhouse effect?

Oxygen is not a significant contributor to the greenhouse effect because it does not trap heat in the atmosphere. The greenhouse effect is primarily driven by gases that can absorb and emit infrared radiation. While oxygen is essential for life and makes up a large portion of the Earth's atmosphere, it does not have the properties necessary to contribute to the greenhouse effect.

In contrast, gases like carbon dioxide, methane, and ozone are known for their ability to absorb infrared radiation, leading to the warming of the atmosphere. Carbon dioxide and methane are particularly noted for their strong contributions to the greenhouse effect due to their ability to trap heat very effectively. Ozone, while naturally occurring in the atmosphere, also plays a role in warming the lower atmosphere.

Understanding the distinctions among these gases highlights the specific character of greenhouse gases and their varying impacts on Earth's climate system.