b. Environmental observations are the foundation for understanding the climate system. From the bottom of the ocean to the surface of the Sun, instruments on weather stations, buoys, satellites, and other platforms collect climate data. To learn about past climates, scientists use natural records, such as tree rings, ice cores, and sedimentary layers. Historical observations, such as native knowledge and personal journals, also document past climate change.

A collection of repeat photography of glaciers from the National Snow and Ice Data Center (NSIDC). The photos are taken years apart at or near the same location, illustrating how dramatically glacier positions can change even over a relatively short period in geological time: 60 to 100 years. Background essay and discussion questions are included.

This video provides background information and teaching tips about the history and relevance of phenology and seasonal observations of plants and animals within the context of rural Wisconsin.

This video describes why tropical ice cores are important and provide different information than polar ice cores, why getting them now is important (they are disappearing), and how scientists get them. The work of glaciologist Lonnie Thompson is featured, with a focus on his work collecting cores of ice from high mountain glaciers that contain significant data about past climate change.

This video montage of spectacular NASA satellite images set to music shows different types of ice and ice features as well as descriptions of satellite-based measurements of ice cover. Text captioning provides guidance as to issues related to changing global ice cover and its measurement.

This video follows biologist Gretchen Hofmann as she studies the effects of ocean acidification on sea urchin larvae.

In this video, a team of paleontologists, paleobotanists, soil scientists, and other researchers take to the field in Wyoming's Bighorn Basin to document how the climate, plants, and animals there changed during the Paleocene- Eocene Thermal Maximum (PETM) when a sudden, enormous influx of carbon flooded the ocean and atmosphere for reasons that are still unclear to scientists. The PTEM is used as an analog to the current warming occurring.

This video, along with a background essay, focuses on impacts of climate change on the lives of Native Alaskans around Barrow, Alaska. Specific changes include the timing of the changes in the formation and breakout of sea ice and the impacts on subsistence living.

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 video discusses observations of two key warning signs of global change effects on the Southern Ocean: changes in Antarctic bottom water and ocean acidification.

This activity supports educators in the use of the activities that accompany the GLOBE Program's Earth System Poster 'Exploring Connections in Year 2007'. Students identify global patterns and connections in environmental data that include soil moisture, insolation, surface temperature, cloud fraction, precipitation, world topography/bathymetry, aerosol optical thickness, and biosphere (from different times of the year) with the goal of recognizing patterns and trends in global data sets.