Home » What Causes Climate Change?
Climate change is a natural process that has been sped up by human activities. The problem today is that we are experiencing an unnatural acceleration of climate change caused by the interplay of several factors, including:
The Earth’s climate is always changing. Natural cycles — occurring over very long time spans — have warmed and cooled the planet over eons. These cycles are driven by slight changes in the Earth’s orbit and/or the amount of solar energy. As a result of these cycles, the Earth has changed dramatically over the eons — the planet’s climate has been both much warmer and much cooler than it is today.
Natural or geologic climate change is driven primarily by shifts in the Earth’s axis around the sun. These changes — known as Milankovitch cycles — affect the angle of the Earth in relation to the sun, and thus affect the amount of solar energy that reaches the planet.
Learn more about natural climate change and how it differs from human-caused climate change. Visit NOAA’s Ocean Service Education website.
Natural or geologic climate change should not be confused with modern climate change. Today, when most people talk about climate change, they are really talking about modern climate change, also known as anthropogenic — human-caused — climate change. The climate change we are experiencing today differs dramatically from geologic climate change because: