There is no denying it: our planet is getting warmer! This means everywhere is getting a little hotter. It may be just a little, but it can have very serious effects on lots of animals and plants. For example, if the ice caps melt, where are polar bears going to live? Also, what’s going to happen with all that water?
The problem is that scientists know this global warming is caused by us. We use a lot of fossil fuels, which release lots of gases into the air. One of those gases is called carbon dioxide (scientists write it as CO2). This gas works like a blanket around our planet and keeps it hot. This is known as the greenhouse effect, because it kinda works like a greenhouse to keep plants warm.