Are you on climate strike today? Quatr.us Study Guides, like most people these days, realizes the tremendous danger facing us today from climate change, and that this climate change is caused by things we’re doing ourselves: driving, using air conditioning and washing machines and dryers, buying new cotton clothing all the time, eating meat, and so on.

Climate changes before people

There were a bunch of climate changes before people evolved. Sometimes the Earth has been so cold that it was completely encased in a ball of ice, all over, with all the water on earth frozen. Other times, it has been so warm that there was no ice at all on Earth, even at the North Pole and South Pole. It’s normal for the earth to change temperature like that. But it’s pretty hard on living things. When the Earth changes temperature like that, sometimes almost all the living creatures on earth die, and new ones have to evolve from the few survivors.

Climate changes since people

This isn’t the first time people have lived through a climate change. In the Quaternary Period, there was a big Ice Age. That Ice Age ended about 13000 years ago, and it’s been pretty warm since then. There was a little Ice Age around the end of the Middle Ages that lasted into the 1800s, but that’s been over for a while too. Ordinarily, there’s been about 10,000 years between Ice Ages, so we would be about due for another one. But because of our cars and our meat and our air conditioning, the Earth is warming instead. So far, we’re nowhere near the hottest Earth has ever been, but we might get there eventually if things go on this way. And remember, events like this have killed almost every living thing on Earth before. (Spiders and cockroaches do okay.)

Climate change in the past and today:

Earth one big ball of ice
So warm that the poles melted
Another ice age
Again very warm

The Quaternary Period
Medieval Warm period
The Little Ice Age
Global Warming today