How Do Scientists Study Past Climates?

How Do Scientists Study Past Climates? 

Scientists study what Earth's climate was like long ago to understand how it is changing now. They use special tools to uncover clues left behind over hundreds and even thousands of years!

Ice Cores 

Scientists drill deep into thick ice sheets and glaciers to remove cylinders of ice. The ice has thin layers from each year of snow. Trapped inside are teeny ancient bubbles of atmosphere. By studying these, scientists can learn what gases were present and what temperatures were like year to year in the ancient past. Ice cores have helped scientists discover our climate history back over 800,000 years!

Tree Rings

Trees add a new growth ring around their trunk each year. The ring will be skinny if conditions are bad that year, and nice and wide if the weather is good. By looking at the ring patterns, scientists can understand weather and climate back as far as the tree has lived, sometimes thousands of years! The oldest tree scientists have studied lived over 5,000 years!

What Have We Learned?

From ice cores, tree rings, and other clues, scientists have learned that Earth's climate has changed a lot over time. Temperatures have gotten warmer and cooler. But the climate is now warming faster than ever before, and scientists are working hard to understand what this means for the future.