Global Warming: Global warming is a gradual increase in the Earth's temperature over time.
Greenhouse Effect: The greenhouse effect causes the Earth to be colder than usual,and the gases polluting the air build up and form a thick layer of substances which trap the sun's radiation.
Gases: Certain gases such as Carbon Dioxide, CFC's and many more, cause the Earth to become warmer.
Littering: Littering pollutes the Earth's air, making a build up of gases stronger, which could lead to the temperature's rising too high in the near future.
Photosynthesis: Photosynthesis is a process where plants use a process of water and carbon dioxide to make food, and to grow and release oxygen into the Earth's atmosphere.
Hope this helps! x