What is Climate Change?

Defined simply, climate change is the process of altering our planet’s current climatic conditions. This involves more than temperature; climate is determined by precipitation patterns, minimum and maximum temperatures, drought, storm intensity and more.

Although climate affects weather, climate is not weather. This is an important distinction. A region can have a hot and dry climate but still experience occasional rainy weather or cold spells. Climate change will not eliminate the possibility of colder-than-average winters. Instead, global climatic changes increase the probability of warmer-than-average winters in most areas.

Visit the NOAA Climate Services website, where you will find current data, informational resources and more.

What Causes Climate Change?

The Earth’s climate is always changing. This is what causes ice ages, for example. In the past, climate change has been driven by geological factors, such as shifts in the Earth’s axis. Modern climate change, however, is caused by increased emissions of greenhouse gases. When atmospheric greenhouse gases are out of balance, and more abundant than in recent history, we observe an amplified “greenhouse effect” where heat is trapped within the atmosphere and temperatures increase.

Learn more about the causes of modern and geologic climate change.

Understanding the Science of Modern Climate Change

The industrial revolution is commonly cited as the beginning of modern climate change because this is when human societies began burning fossil fuels in large quantities. Those fossil fuel emissions contribute to climate change by essentially increasing the amount of insulation in the Earth’s atmosphere.

Learn more about the science of modern climate change

Facts, Data and Examples of Modern Climate Change

Review our regularly-updated list of current facts and data about the science of climate change, including observed and predicted temperature changes, climate change impacts, and ongoing greenhouse gas emissions. View the list or learn more about regional impacts and resources for additional information.