Scientists learn about climate and how it has changed by studying climates of the past. By analyzing changes that have occurred in the earth's temperature over time, scientists can gain a better understanding of global warming, and make determinations about its possible causes.

Scientists have discovered ways to study the earth's climate, going back as far as thousands, or even millions, of years. Those who specialize in studying ancient climates are known as paleoclimatologists, a name derived from the Greek root word paleo, which means ancient. Paleoclimatologists use natural elements in the environment to find "proxy climate data" related to the past. When they study these types of data, these scientists typically use several different methods, so they are assured of forming the most accurate analysis possible.

Tree Rings Tell a Story

One way that paleoclimatologists unlock the secrets of...