Multiple choice What likely caused the decline of the Indus River Valley civilisation? Aryan invasion from the north Global cooling period damaged their crops Environmental degradation, flooding, and/or earthquakes Dravidian invasion from southern India Reveal answer Fill a bubble to check yourself C Correct answer Explanation Most historians agree that the decline of the Indus Valley Civilization was caused by a combination of environmental factors, such as climate change, shifting river courses, and natural disasters like earthquakes.