The past 12 months have been the hottest on record, according to the National Oceanic and Atmospheric Administration. Throughout the nation, drought, wildfires, floods and other extreme weather have made global warming a visible reality.

So it was tragic that both presidential candidates spent significant time during Tuesday’s debate trying to one-up each other on how much more fossil fuels they plan to extract, burn and allow into the atmosphere. In three debates so far, climate change hasn’t been mentioned once.

Moderator Candy Crowley said that one of the “undecided” voters at the debate had prepared a climate-change question, but she didn’t call on that person: “We just, you know, again, we knew that the economy was still the main thing.”

Yeah, we know. But if the nation, and the world, doesn’t get serious about climate change — like, right now — the jobs of the future are at serious risk. Unfortunately, as MSNBC’s Chris Hayes pointed out, future farmers of America whose crops will be destroyed by climate change are too young to vote in this election. Then again, if climate change isn’t halted, jobs won’t be the worst worry for future farmers — or nurses, or teachers, or factory workers. Survival will.

Yet there was Mitt Romney challenging President Obama: “This has not been Mr. Oil, or Mr. Gas, or Mr. Coal,” as if that were a bad thing. The president went right back at Romney, challenging his assertion that he “is a big coal guy,” as if that were a good thing, and furthering the myth there is such a thing as “clean coal.”

The bragging came after a question that also reflected a myth: that the president or the government has power over gas prices.

But the political necessity to frame renewable energy as part of a jobs program, rather than a necessary response to the most pressing issue of our time, does the country a disservice.

An organization called Climate Silence (climatesilence.org) is offering graphics to use on social media as part of a campaign to demand that the climate-change question be asked. It’s surely an appropriate question for Monday’s debate on foreign policy: Climate change is a national security threat greater than any we ever have faced.