c. Human activities have affected the land, oceans, and atmosphere, and these changes have altered global climate patterns. Burning fossil fuels, releasing chemicals into the atmosphere, reducing the amount of forest cover, and the rapid expansion of farming, development, and industrial activities are releasing carbon dioxide into the atmosphere and changing the balance of the climate system.

This video describes what black carbon is, where is comes from, and how it contributes to sea ice melt and global warming.

In this interactive simulation, students can explore global CO2 emissions displayed by different continents/countries and plotted based on the GDP. A map view is also accessible.

This video is one of a seven, Climate Change: Lines of Evidence series, produced by the the National Research Council. It outlines and explains what evidence currently exists in support of humans playing a role in contributing to the rise in atmospheric carbon dioxide levels.

This beautifully filmed and produced video describes the changes that global warming is already bringing to Northern Canada and Greenland. Local people describe changes to ecosystems, impacts on culture and life styles, and the challenges of melting permafrost. Ship captains describe changes in navigational channels and fjords. Scientists describe changes in albedo and permafrost, as well as increased pollution transported from outside the Arctic (the Grasshopper effect).

This short video describes the Hestia project - a software tool and data model that provide visualizations of localized CO2 emissions from residential, commercial, and vehicle levels, as well as day versus night comparisons, in the city of Indianapolis.

This NASA animation on land cover change zooms into Rondonia, Brazil. It starts with a Landsat satellite image taken in 1975 and dissolves into a second image of the same region taken in 2009 that illustrates a significant amount of land use change.

This video segment from 'Earth: The Operators' Manual' explores how we know that today's increased levels of CO2 are caused by humans burning fossil fuels and not by some natural process, such as volcanic out-gassing. Climate scientist Richard Alley provides a detailed step-by-step explanation that examines the physics and chemistry of different "flavors," or isotopes, of carbon in Earth's atmosphere.

This video examines the thawing of permafrost due to changes in climate and shows examples of the impacts that warming temperatures have on permafrost in the Arctic, including the release of the greenhouse gas methane. Dramatic results are shown, including sink holes forming on the landscape and beneath buildings, roads, and other infrastructure, causing some communities to relocate.

In this lab activity, students use a chemical indicator (bromothymol blue) to detect the presence of carbon dioxide in animal and plant respiration and in the burning of fossil fuels and its absence in the products of plant photosynthesis. After completing the five parts of this activity, students compare the colors of the chemical indicator in each part and interpret the results in terms of the qualitative importance of carbon sinks and sources.