This is the seventh of nine lessons in the 'Visualizing and Understanding the Science of Climate Change' website. This lesson addresses climate feedback loops and how these loops help drive and regulate Earth's unique climate system.

This video explores the work of environmentalist John Hart, a Professor of Environmental Science at U.C. Berkley. In the Rocky Mountains of Colorado, Dr. Hart has established an experimental laboratory in which he has artificially created and maintained a 3-degree increase in surface temperature of a plot of land, and documented the impact on plant species occupying the plot.

In this activity for undergraduates, students explore the CLIMAP (Climate: Long-Range Investigation, Mapping and Prediction) model results for differences between the modern and the Last Glacial Maximum (LGM) and discover the how climate and vegetation may have changed in different regions of the Earth based on scientific data.

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 activity describes the flow of carbon in the environment and focuses on how much carbon is stored in trees. It goes on to have students analyze data and make calculations about the amount of carbon stored in a set of trees at three sites in a wooded area that were to be cut down to build a college dormitory.

This activity introduces students to stratigraphic correlation and the dating of geologic materials, using coastal sediment cores that preserve a record of past hurricane activity.

This teaching activity addresses regional variability as predicted in climate change models for the next century. Using real climatological data from climate models, students will obtain annual predictions for minimum temperature, maximum temperature, precipitation, and solar radiation for Minnesota and California to explore this regional variability. Students import the data into a spreadsheet application and analyze it to interpret regional differences. Finally, students download data for their state and compare them with other states to answer a series of questions about regional differences in climate change.

This video segment, adapted from Need to Know, discusses how the process of hydraulic fracturing (fracking) is used to extract natural gas and how the process may be polluting water resources with hazardous chemicals, leading to health concerns.

This NASA video reviews the role of the sun in driving the climate system. It uses colorful animations to illustrate Earth's energy balance and how increased greenhouse gases are creating an imbalance in the energy budget, leading to warming. The video also reviews how the NASA satellite program collects data on the sun.

In this activity, students analyze data maps of sea surface temperature anomalies for a 14-year interval and create an ENSO time line in a case study format. Based on their findings, students determine the recurrence interval of the ENSO system.