This is the first of nine lessons in the "Visualizing and Understanding the Science of Climate Change" website. This lesson is an introduction to Earth's climate and covers key principles regarding Earth's unique climate, atmosphere, and regional and temporal climate differences.

This is a classroom activity about the forcing mechanisms for the most recent cold period: the Little Ice Age (1350-1850). Students receive data about tree ring records, solar activity, and volcanic eruptions during this time period. By comparing and contrasting time intervals when tree growth was at a minimum, solar activity was low, and major volcanic eruptions occurred, they draw conclusions about possible natural causes of climate change and identify factors that may indicate climate change.

This video provides an overview of changes happening in the Arctic.

This article and slide show from the New York Times, features several scientists from the University of Alaska, Fairbanks, who study the effects of thawing permafrost in Alaska.

In this activity, students compare carbon dioxide (CO2) data from Mauna Loa Observatory, Barrow (Alaska), and the South Pole over the past 40 years to help them better understand what controls atmospheric carbon dioxide. This activity makes extensive use of Excel.

In this short video from ClimateCentral, host Jessica Harrop explains what evidence scientists have for claiming that recent global warming is caused by humans and is not just part of a natural cycle.

This video features research conducted at University of Colorado's Institute of Arctic and Alpine Research, which studies isotopes of hydrogen trapped in ice cores to understand climate changes in the past.

This interactive shows the different components of the ocean biological pump, i.e., how carbon in the form of either plankton or particles moves into the ocean's depths. It illustrates the situation at the surface, 0-100 meters, 100-500 meters, and below 500 meters.

This high-resolution narrated video shows levels and movements of CO2 globally through the course of a year.

This short video examines the recent melting ice shelves in the Antarctica Peninsula; the potential collapse of West Antarctic ice shelf; and how global sea levels, coastal cities, and beaches would be affected.