Google on Wednesday plans to deliver an update to its Google Earth application that includes content from a number of premium sources. The features are overlaid atop areas in a map so users can learn about their significance.

Perhaps the most notable addition is before and after imagery provided by the United Nations Environmental Program, which shows 100 areas of extreme environmental degradation around the world. Users can click to see how the Earth has changed in the past 30 years, primarily for the worse, and learn about crisis zones.

Content from the National Parks Service will overlay information on over 10,000 trails and 58 national parks atop satellite images, offering detailed park descriptions and visitor information. The Jane Goodall Institute will let users track Fifi and the other Gombe preserve chimpanzees from within Google Earth.

A Turn Here feature includes city video guides told from an insider's perspective, Google says, connecting users to hidden gems in cities around the world from New York to Stockholm.

Google says the initial list of content providers will be expanded and updated automatically over time. Users can recognize the content features through special icons, and is located in Google Earth's "Layers" section. Existing users will see the new content show up without having to update their software.