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NASA's World of Change
Completion requirements
Earth is constantly changing. Some changes are a natural part of the climate system, such as the seasonal expansion and contraction of the Arctic sea ice pack. The responsibility for other changes, such as the Antarctic ozone hole, falls squarely on humanity’s shoulders. Our World of Change series documents how our planet’s land, oceans, atmosphere, and Sun are changing over time.
Click https://earthobservatory.nasa.gov/Features/WorldOfChange/ link to open resource.