Answer: Global warming is happening because the greenhouse gases are becoming more thicker which makes more of the suns radiation (heat) stay in the earth; as a result, this is increasing the earth's temperature.
The subject is geography :)
Explanation:
Las Ciencias de la Tierra o Geociencias conciernen y engloban las disciplinas que estudian la estructura, morfología, evolución, y dinámica del planeta Tierra. Constituye un caso particular de las ciencias planetarias, que se ocupan ellas del estudio de los planetas del Sistema Solar.
Answer: Differences of opinions, ethics, and rivalry possibly