Climate History: Toppling Empires (Independence Day Special!) Ben Climate Science, History, YouTube Channel July 4, 2019September 3, 2021Climate History, Climate Science, Independence Day, Sustainability On July 4, 1776, the Declaration of Independence was signed, declaring our country’s independence from Great Britain. Since then the US has historically risen to a global superpower. Today we are taking a look at past civilizations and how Climate Change affected their dominance.