Apple has published a new series of videos in celebration of Earth Day that both highlight the company’s green energy efforts and explain some of the science behind clean energy today. The video series includes comical illustrations and narrations from Apple execs including VP Lisa Jackson.

Each video poses a question and features an Apple employee explaining the company’s environmental strategy:

Do solar farms feed yaks?

Lisa Jackson, Apple’s lead on Environment work, gives a crash course on how our 40-megawatt solar farms in China produce enough electricity for all of Apple’s offices and retail stores in the country—and grass to feed yaks.

Can we produce zero waste?

None of Apple’s 14 final assembly facilities in China send any waste to landfills. As in zero. And that all started when John Reynolds in iPhone Product Operations visited a factory in Guanlan, China.

Why does Apple make its own sweat?

Apple’s toxicology experts Rob Guzzo and Art Fong will grossly tell you how we make about 30 gallons worth of sweat every year, and how it keeps you safe.

Can a building breathe?

Apple Park uses outside air to cool the building naturally, reducing the campus’ cooling load by 35 percent a year. Apple’s VP of Real Estate, Dan Whisenhunt, breaks down why this is well…cool.

In addition to the new video series, Apple has shared a lofty goal of making all of its products from recycled material at some point in the future. Apple is also hosting an Apple Watch Activity Challenge for Earth Day on Saturday that encourages customers to go outside and exercise for 30 minutes to unlock special Earth Day iMessage stickers.

Check out the full video series below: