Bertha Vazquez has taught earth science for more than 25 years.

"For many years I covered the basic standard, probably like most people in the country do," she says.

Then one day, she says, she decided to throw that all out the window after seeing former Vice President Al Gore speak at the University of Miami at a screening of An Inconvenient Truth, his documentary about climate change.

"And it really ... hit me. This is 2007 and, I've got to tell you, I lost sleep," Vazquez says.

A study in the journal Science this spring found that half of U.S. science teachers spend less than two hours on climate change each year.

And teachers in Florida may be no exception. Florida is one state that has not adopted somewhat newly designed science standards that are gaining popularity and teach about human-induced climate change.

So, Vazquez says, the next day in class she resolved to do more. The school where she teaches, George Washington Carver Middle School, sits just eight feet above sea level; several of the surrounding neighborhoods are even lower.

She thought, by the time her students were adults with families of their own, storm surges could bring waves lapping at their front doors. "If we just despair, it leads to inactivity," she says. "So I thought, 'If they're doing positive things, it will be helpful.' "

And positive things they're doing.

Vazquez's students meet climate scientists in class and calculate how many desalination plants it would take to turn rising seas into a sustainable source of fresh water (too many).

There's the work they've done on the school itself. On a walk around campus, Vazquez points out improvements her students instigated over the years or installed themselves: smart thermostats, energy-efficient light bulbs, and reflective white paint on the roof to keep the building cooler.

Finally, there are students like Penny Richards. She says after a year in Vazquez's class, she reads climate news while she rides the bus to school.

In class, Bertha Vazquez says she tries to balance the fear that comes with taking climate science seriously, and measured optimism. She draws on examples of past environmental successes — like how the ozone layer is on the mend — to show what collective action can accomplish.

"In your lifetime, you're going to see a sea change," Vazquez explains to her students at the end of class. "I don't want you all to walk out of here like, 'Woe is me, it's going to be over!' "

Privately, though, she acknowledges a cognitive dissonance in teaching about the onset of a planet-sized crisis while smiling at sixth-graders.

"You can't depress the hell out of them ... if you want them to start looking for solutions," she says. "So I don't really go there. Do I feel that way personally? Yes ... but in class I put on my happy face."

A pivotal moment in Vazquez's class often comes when her students open an app called Eyes on the Rise, where they plug in their address and learn how far they live above sea level.

"One kid will say, 'I'm 10 feet above sea level. I'm going to be OK,' " Vazquez explains. "I'll say 'Yeah, you'll be on a little hill, but what about everybody else around you? We're all in this boat together.' "

For students like seventh-grader Penny Richards — the one who reads climate news on the bus — that's a sobering moment. "Miami's basically at sea level. I live next to a canal," she reasons. "Life as we know it, we're going to have to move to an entirely different setting soon if we don't do something about this, because my entire neighborhood will be underwater."

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