Clouds have both cooling and warming effects on Earth's surface. Figuring how they balance is tricky. Determining global cloud cover over time is a major aspect of understanding climate change.
Some clouds help cool the Earth, but other clouds help keep Earth warm – in part depending on how high up they are in our atmosphere. That's according to Steven Platnick, a satellite researcher with NASA. He studies clouds and how they connect with Earth's climate. He said that low, fluffy clouds keep us cooler.
Steven Platnick: You can appreciate that if you go out on a hot and sunny day, and a cloud passes by overhead, it's a great relief from the heat. And the reason of course is because the cloud is reflecting sunlight.
But it's a different story for clouds that are high up in the atmosphere, said Platnick. Those high, wispy clouds actually keep Earth warm, like a blanket, by preventing heat from escaping into space. Platnick uses NASA's Aqua satellite to determine the height of clouds, and other properties of clouds as well -- like what's inside them, how much water they have, and whether a cloud is primarily liquid or ice. The satellite also tracks the amount of cloud cover all over the world.