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.

Activity in which students investigate what causes the seasons by doing a series of kinesthetic modeling activities and readings. Activity includes educator background information about how to address common misconceptions about the seasons with students.

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 shows 15 years of data obtained via Polar-orbiting satellites that are able to detect subtle differences in ocean color, allowing scientists to see where there are higher concentrations of phytoplankton - a proxy for the concentration of chlorophyll in the ocean.

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 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).

In this activity students learn how Earth's energy balance is regulating climate. This activity is lesson 4 in the nine-lesson module Visualizing and Understanding the Science of Climate Change.

This animated visualization represents a time history of atmospheric carbon dioxide in parts per million (ppm) from 1979 to 2016, and then back in time to 800,000 years before the present.

This video segment, from the 'Earth: The Operators' Manual' featuring climate expert Richard Alley, shows how ice cores stored at the National Ice Core Lab provide evidence that ancient ice contains records of Earth's past climate - specifically carbon dioxide and temperature.

This collection of photos from the NASA Climate website features images of global change, such as floods, wildfires, and retreating glaciers. Not all images show change caused directly by climate change and energy use, and descriptive captions indicate causes for change in most of the images.