Over the past 100 years, we’ve witnessed some of the most profound changes in human history. 

Between wars, technological developments, progress in civil rights, and breakthroughs in science and medicine, the old order that oppressed hundreds of millions of people has been swept away, sometimes giving way to freer forms of governing and sometimes not.

Centuries-old empires crumbled as new ideologies — from communism to fascism — took root in many parts of the world. The 20th century began in turmoil, ushering in two world wars that led to the end of the colonial world and birthed new nations. These wars also cost millions of lives and trillions of dollars. These are the most expensive wars in U.S. history. 

Throughout the past century, technology evolved, modifying and innovating our lives in ways never dreamed of. Progressive ideas also emerged and changed the world as women, African Americans, and the LGBTQ community demanded, and often won, equal rights — from the ratification of the 19th Amendment to the legalization of same-sex marriage.

The world certainly has progressed, but wars have raged on, and devastating changes to our climate now endanger the ecosystems of our planet. In the coming years, natural disasters may have an increasingly impactful role on the course of history. Here are 26 disaster scenarios caused by climate change.

To determine the most important event the year you were born, 24/7 Wall St. drew on research materials and media sources to compile its list. Deciding the most important event in a given year by its nature is a subjective exercise. In reaching our decisions, we chose the event that had the most far-reaching impact, even if it was not necessarily the most famous event in a given year.

Click here to read the most important event the year you were born