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.

In this video clip, Climate Central's Dr. Heidi Cullen explains that what we've known as "normals" for our climate, during the past decade, will very likely change soon. The new climate normal will provide key information for decisions we make in the future, ranging from what we plant, to what we pay for energy, and even to where we take a vacation.

This short cartoon video uses a simple baseball analogy (steroid use increases probability of hitting home runs) to explain how small increases in greenhouse gases can cause global temperature changes and increase the probability of extreme weather events.

This series of visualizations show the annual Arctic sea ice minimum from 1979 to 2010. The decrease in Arctic sea ice over time is shown in an animation and a graph plotted simultaneously, but can be parsed so that the change in sea ice area can be shown without the graph.

This video, from ClimateCentral, features a team of scientists from the Northern Greenland Eemian Ice Drilling Project (NEEM), who study atmospheric air bubbles trapped in an ice core from 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 - all aligned on the same time scale - reveal what happened with climate change over that period of time.

In this TED talk, Wall Street Journal science columnist Lee Hotz describes the research of the Western Antarctic Ice Sheet (WAIS) Divide project, in which scientists examine ice core records of climate change in the past to find clues to climate change in the future.

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.

In this activity, students study the relationship between changing climate conditions and the distribution of plants across North America, using a unique tool called the Pollen Viewer. This tool allows the user to animate the retreat of the North American glacier and the migration of plant species during the waning period of the most recent Ice Age.

This is an interactive website that provides descriptive information and data related to ten key climate indicators. These climate indicators and related resources show global patterns and data that are intuitive and compelling teaching tools.

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.

In this activity, students create graphs of real temperature data to analyze climate trends by analyzing the global temperature record from 1867 to the present. Long-term trends and shorter-term fluctuations are both evaluated. The data is examined for evidence of the impact of natural and anthropogenic climate forcing mechanisms on the global surface temperature variability. Students are prompted to determine the difficulties scientists face in using this data to make climate predictions.