Question

1. how do increased greenhouse gases affect the earth?

greenhouse gases trap heat in the atmosphere, warming the planet.
greenhouse gases absorb water vapor from earths atmosphere, warming the planet.
greenhouse gases turn oxygen into a different substance that heats up the planet.
greenhouse gases trap heat in the atmosphere, lowering the temperatures

Explanation:

Greenhouse gases like carbon dioxide, methane etc. have the property of trapping the heat (infra - red radiation) that is reflected back from the Earth's surface. This trapped heat leads to an increase in the overall temperature of the planet. Water vapor is itself a greenhouse gas and not absorbed by other greenhouse gases in a way that warms the planet. Greenhouse gases do not convert oxygen into a heating - substance. And trapping heat would not lower the temperatures.

Answer:

Greenhouse gases trap heat in the atmosphere, warming the planet.