This computer-based learning module engages students in questions that scientists around the world are exploring about Earth’s climate. They gain an appreciation for how much is not known about the Earth and climate change. The module contains 5 activities; 1) Earth’s Changing Climates, 2) Interactions Within the Atmosphere, 3) Sources, Sinks, and Feedbacks, 4) Feedbacks of Ice and Clouds, and 5) Using Models to Make Predictions. Each activity provides information in simulations, text, video, or graphic format and the students enter answers to both open-ended and closed questions within the program. Once the students have completed an activity, they can print a report showing all the questions and their answers. The authors estimate the entire module should take 225 minutes. A teacher’s guide with answers to the questions and a PDF with instructions for using the portal with students can be found at http://resources.has.concord.org/resources/teacher%20guides/ClimateTG2014.pdf. In Activity 1, students look at climate trends over different time scales. They evaluate the information the data provides and consider the limitations of conclusions that can be drawn from the data. In Activity 2, students study how solar radiation interacts with components of Earth's surface and atmosphere, and learn how greenhouse gases warm Earth's atmosphere. In Activity 3, they explore the relationships between levels of atmospheric carbon dioxide and water vapor and ocean and surface temperature. In Activity 4, they discover how light-colored surfaces, such as snow, ice, and some clouds, have a cooling effect on Earth's temperature. In Activity 5, students explore how solar radiation, Earth's surface and oceans, and greenhouse gases interact to cause global warming. They change variables to determine how much greenhouse gas emissions might need to fall to mitigate the projected temperature increase.