Amanda Clement and Whitney Masters giggled as they used straws to blow bubbles in beakers containing a pink solution.

A minute later, the water was clear.

There’s some complex chemistry at work, but the lesson from the Glendale Community College students was simple: Carbon dioxide in breath creates carbonic acid in the solution, the same way carbon-dioxide emissions from cars acidify sea water, harming coral reefs and other marine life.

Students around Arizona saw green this week as colleges and universities participate in a nationwide teach-in about climate change. More than 1,000 schools overall were said to be participating in Focus the Nation: Global Warming Solutions for America.

As they looked at a hydrogen-powered car and displays about endangered wildlife, public transportation and other topics Wednesday, students and administrators at GCC said college-age people are the key to reducing the effects of global warming.

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