Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between NOAA and NSTA, is the third of four Science Objects in the Resources and Human Impact SciPack. It explores how human activities, such as reducing the amount of forest cover, increasing the amount and variety of chemicals that enter the atmosphere, intensive farming and fishing, and consuming fossil fuels have changed Earth’s land, oceans, and atmosphere. Although the land, atmosphere, and the oceans have a limited capacity to absorb wastes and recycle materials naturally, humans have disrupted these natural cycles. Fresh water, limited in supply, is essential for life and most industrial processes. Overuse and pollution of rivers, lakes, oceans, and groundwater reduces the availability and suitability of these resources for all organisms. Technology used in the extraction and consumption of fossil fuels needed to meet the growing human demand has increased the depletion of nonrenewable energy resources such as fossil fuels, and degraded or altered the environment, both locally and globally.