The 20th Century was dominated by chain of events that heralded significant changes in world history as to redefine the era: World War I and World War II, nuclear power and space exploration, nationalism and decolonization, the Cold War and Post-Cold War conflicts; intergovernmental organizations and cultural homogenization through developments in emerging transportation and communications technology; poverty reduction and world population growth, awareness of environmental degradation, ecological extinction;[4][5] and the birth of the Digital Revolution