d. Humans may be able to mitigate climate change or lessen its severity by reducing greenhouse gas concentrations through processes that move carbon out of the atmosphere or reduce greenhouse gas emissions.

This video segment examines ethanol, a cleaner-burning fuel alternative to gasoline, and the efforts to produce it more efficiently.

In this video from Young Voices for the Planet, four middle-school girls (The Green Team) talk about their efforts to work with their peers to reduce the carbon footprint of their school and how they made the school more energy efficient.

One of a suite of online climate interactive simulations, this Greenhouse Gas Simulator uses the bathtub model to demonstrate how atmospheric concentrations of CO2 will continue to rise unless they are lowered to match the amount of CO2 that can be removed through natural processes.

This PBS video shows how Klaus Lackner, a geophysicist at Columbia University, is trying to tackle the problem of rising atmospheric CO2 levels by using an idea inspired by his daughter's 8th-grade science fair project.

This Flash-based simulation explores the relationship between carbon emissions and atmospheric carbon dioxide using two main displays: (1) graphs that show the level of human-generated CO2 emissions, CO2 removals, and the level of CO2 in the atmosphere, and (2) a bathtub animation that shows the same information as the graphs. The bathtub simulation illustrates the challenges of reducing greenhouse gas concentrations in the atmosphere.

This short video reviews how nations and individuals can work together to reduce the emission of CO2. It discusses strategies to reduce greenhouse gas emissions (energy conservation, renewable energies, change in energy use) and the role that government can play in this process.

C-Learn is a simplified version of the C-ROADS simulator. Its primary purpose is to help users understand the long-term climate effects (CO2 concentrations, global temperature, sea level rise) of various customized actions to reduce fossil fuel CO2 emissions, reduce deforestation, and grow more trees. Students can ask multiple, customized what-if questions and understand why the system reacts as it does.

This is a series of 10 short videos, hosted by the National Science Foundation, each featuring scientists, research, and green technologies. The overall goal of this series is to encourage people to ask questions and look beyond fossil fuels for innovative solutions to our ever-growing energy needs.

This carbon calculator, developed by the EPA, guides students in calculating their carbon footprint and then using that information to make decisions about how to reduce their carbon emissions.