Today I learned that Earth’s climate fluctuates between two dominant climate states that last for millions of years, ice age (icehouse) and greenhouse periods. The cause of these ice ages is not fully understood but it’s believed to be dependent on factors such as the Earth’s orientation and orbit, amount of carbon dioxide in the air, volcanic activities, etc. There have been at least 5 major ice ages during which polar ice sheets expand and global temperatures drop significantly. It’s hypothesized that during one of the ice ages, the earth might have become a snowball when glacial ice sheets reached the equator. A time when people didn’t have to swim oceans for each other because they could simply walk over them. With that said, it might come as a surprise that we are currently in an ice age.
The current ice age started around 2.58 million years ago. During the ice age periods, there are intermittent warm periods that makeup around 20% of the time in total. We are currently in one of the warm periods, a.k.a., interglacial period, instead of the cold one, a.k.a., glacial period. One might wonder what a wonderful time to be alive. Not only the other million conditions that made life possible on the only planet in the universe known to possess life are favorable, but we are also in a very comfortable intermittent warm spot in the middle of an ice age. I for one couldn’t have survived the harsh conditions of the glacial period that ended 12,000 years ago which our ancestors clearly did. Behaviorally modern humans came into existence about 60,000 years ago. So the majority of the humans who ever existed had to deal with it unlike you and me. Yet we don’t have any firsthand account of the everlasting winters because we only started writing about 5,000 years ago. Yup, if it wasn’t for the current interglacial period, we probably wouldn’t have invented agriculture, writing, civilizations, and of course the internet by now. None of your problems would have existed and neither would have you. Learning this opened my eyes when I realized why Hollywood is so obsessed with snow and ice when it comes to ancient-civilization themed movies and TV shows. Suddenly, the Old Nan from GoT started making a lot more sense.
“Oh, my sweet summer child,” Old Nan said quietly, “what do you know of fear? Fear is for the winter, my little lord, when the snows fall a hundred feet deep and the ice wind comes howling out of the north. Fear is for the long night, when the sun hides its face for years at a time, and little children are born and live and die all in darkness while the direwolves grow gaunt and hungry, and the white walkers move through the woods” ~ George R.R. Martin, A Game of Thrones
Thanks to what we managed to do in the past 500 minuscule years, we have postponed the end of the current interglacial period to 100,000 years in the future which otherwise could have happened 50,000 years from now. The only other thing that baffles me is how we were never taught about any of this in school. How didn’t the teachers start every day by acknowledging the luckiest time to go outside and walk around.. even though we probably would still just stay inside and binge-watch the entire day?