Climate change is real and happening now.
Climate change is real. Global warming is real. National parks and communities across the country are already experiencing the impacts. Maybe you’ve noticed them, too.
How do we know that climate change is happening? Scientists who study Earth’s climate use a variety of scientific methods to track climate change over generations, centuries, and millennia. Among their methods are the comparison of temperature data with sea levels, size and number of glaciers, length of fire seasons, movement and composition of human and animal populations, and condition of arctic permafrost.
Scientists agree that we are now living with hotter temperatures than people have ever experienced in all of human history. And they don’t see an overall cooling trend in Earth’s climate coming anytime soon.
Last updated: February 3, 2015