Environmental Science

A natural resource is....

a renewable resource is ....

Choose ALL of the renewable resources

Choose ALL of the nonrenewable energy resources

A minor but very important component of the atmosphere (in terms of concentration). It is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. Humans have increased its atmospheric concentration by more than a third since the Industrial Revolution began. This is the most important long-lived "forcing" of climate change.

A hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as cattle digestion and manure management associated with domestic livestock. On a molecule-for-molecule basis, it is a far more active greenhouse gas than carbon dioxide, but also one which is much less abundant in the atmosphere.