Respond to student
The textbook defines natural resources as a useful material that is obtained from the lithosphere, atmosphere, hydrosphere, or biosphere. Natural resources have not only been vital to our civilization but the depletion of natural resources has been a significant factor in the collapse of civilizations as well. The Rapa Nui civilization is an excellent example of how greatly a civilization is affected by loss of natural resources. As the islanders managed to cut down every last tree on the island, it is thought to have brought about their demise. With the land now susceptible to erosion and baron, famine and tribal wars was the result, ultimately ending in the loss of that civilization.
Alternative energy is any energy source that is an alternative to fossil fuel. These alternatives are intended to address concerns about fossil fuels, such as its high carbon dioxide emissions, an important factor in global warming. For thousands of years, humans have harnessed the wind to push sails, mill grain, and pump water. Today, windmills use turbines to convert rotational energy into electricity that can reliably flow into to a grid. On a larger scale, wind farms are projected to provide as much as 20% of global electricity production by 2020. .