As experts in climate science, it’s our responsibility to tell you what we know. Climate change isn’t going to happen; it’s already happening.
Hear From the Scientists
Based on the evidence, about 97% of climate experts have concluded that human-caused climate change is happening. What We Know helps us understand the science behind the realities, risks and response to the climate challenge.
Read the Backgrounder » As experts in climate science, it’s our responsibility to tell you what we know. Climate change isn’t going to happen; it’s already happening.