Explain how greenhouse gases
contribute to global warming?

Greenhouse Gases are a collection of the Earth's radiation. Therefore it accumulates in the atmosphere and heats up the Earth's surface

Greenhouse gases are gases that get trapped in the atmosphere. For example, carbon dioxide is a greenhouse gas. Since these gases trap heat, the more gases, the more heat that is trapped. We are constantly putting these gases in the atmosphere, so that's why the global temps are rising.