g. Natural processes that remove carbon dioxide from the atmosphere operate slowly when compared to the processes that are now adding it to the atmosphere. Thus, carbon dioxide introduced into the atmosphere today may remain there for a century or more. Other greenhouse gases, including some created by humans, may remain in the atmosphere for thousands of years.

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.

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.

This short video discusses where carbon dioxide, the gas that is mainly responsible for warming up our planet and changing the climate, comes from. It discusses how the rise in atmospheric carbon dioxide comes directly from the burning of fossil fuels and indirectly from the human need for energy.

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.

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