This graph, based on key ice core data sets and recent monitoring programs, shows the variations in concentration of carbon dioxide (CO2) in the atmosphere during the last 400,000 years.

This series of four animations shows how some of the key indicators of climate change (average global temperature, sea level, sea ice extent, carbon emissions) have changed in Earth's recent history.

This short video, adapted from NOVA, explains how Earth's position relative to the Sun might be responsible for the dramatic shift in the climate of what is now the Saharan nation of Djibouti.

This interactive visualization from the NASA Earth Observatory website compares Arctic sea ice minimum extent from 1984 to that of 2012.

This video considers the current estimates of sea level rise as possibly too conservative and discusses more recent data on ice melt rates coming from Antarctica and Greenland, showing rates of melt at up to 5 times as rapid. Scientists discuss what levels and rates of sea level rise have occurred in the past, including the Pliocene, which demonstrated 1m rise every 20 years.

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 video, a spokesperson for the National Climactic Data Center describes the methods of using satellites (originally designed for observing changes in the weather) to study changes in climate from decade to decade. The video clearly illustrates the value of satellite data and begins to address connections between weather and climate.

This video features University of Wisconsin-Madison researcher John Magnuson, who studies the ecology of freshwater systems. He explains the difference between weather and climate using data on ice cover from Lake Mendota in Madison, WI. Analysis of the data indicates a long-term trend that can be connected to climate change.

This interactive lets students determine the extent of average temperature change both in their community and anywhere else in the world, relative to average temperatures for the three decades between 1951 and 1980.

This NASA animation presents the levels of atmospheric carbon dioxide over the last 400,000 years, last 1000 years and last 25 years at different time scales. The data come from the Lake Vostok ice cores (400,000 BC to about 4000 BC), Law Dome ice cores (1010 AD to 1975 AD) and Mauna Loa observations (1980 to 2005).