Clouds cover about 70% of the planet at any moment. But what if — poof — they all disappeared? Long story short, we'd have huge problems on our hands.

Most of us are used to seeing Earth from the Northern Hemisphere because this half of the globe is home to 68 per cent of the planet's land.

If you take a look at global temperature graphs that span millions or billions of years, you can see that our planet’s temperature has made wild swings. In fact, the Earth used to be completely ...