d. Scientific observations indicate that global climate has changed in the past, is changing now, and will change in the future. The magnitude and direction of this change is not the same at all locations on Earth.

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.

Key figure from the 2007 Intergovernmental Panel on Climate Change (IPCC) report that shows changes in global average surface temperature, global average sea level, and Northern Hemisphere snow cover from as far back as 1850.

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.

In this video, a PhD Student from the University of Maine explains how ice cores are used to study global climate change.

In this learning activity, students use a web-based geologic timeline to examine temperature, CO2 concentration, and ice cover data to investigate how climate has changed during the last 715 million years.

This is a video overview of the history of climate science, with the goal of debunking the idea that in the 1970s, climate scientists were predicting global cooling.

In this activity, students use Google Earth to explore global temperature changes during a recent 50 - 58 year period. They also explore, analyze, and interpret climate patterns of 13 different cities, and analyze differences between weather and climate patterns.

In this audio slideshow, an ecologist from the University of Florida describes the radiocarbon dating technique that scientists use to determine the amount of carbon within the permafrost of the Arctic tundra. Understanding the rate of carbon released as permafrost thaws is necessary to understand how this positive feedback mechanism is contributing to climate change that may further increase global surface temperatures.

In this activity, students reconstruct past climates using lake varves as a proxy to interpret long-term climate patterns. Students use data from sediment cores to understand annual sediment deposition and how it relates to weather and climate patterns.

This video, from ClimateCentral, features a team of scientists from the Northern Greenland Eemian Ice Drilling Project who study atmospheric air bubbles trapped in an ice core. This work highlights a period in Greenland's ice sheet which began about 130,000 years ago and lasted about 10,000 years; a period known as the Eemian. The air bubbles from the ancient atmosphere reveal what happened with climate change over that period of time.

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