Over millions of years, Earth's climate has warmed up and cooled down many times. However, today the planet is warming much faster than it has over human history.
Global air temperatures near Earth's surface have gone up about 2 degrees Fahrenheit in the last century. In fact, the past five years have been the warmest five years in centuries.
A couple of degrees may not seem like much. However, this change can have big impacts on the health of Earth's plants and animals.
Climate changes faster than animals adapt