Childhood obesity is increasing rapidly among America’s children. So are rates of diabetes and attention-deficit disorder, and overall academic scores are falling as a result.

So what’s the solution? According to the Sierra Club, we should tax those lazy twerps …

Er, um, well maybe not the kids, but the devices they use as excuses for not going outside and getting exercise, such as video games and consoles, TVs and computers.

The environmental preservation group believes such a tax could fund programs — even electronic ones — that teach children about the great outdoors and encourage them to get up off their duffs and go play, hike and run outside.

A 1 percent added tax on sales of electronic entertainment and games, the Sierra Club believes, could generate about $4 million toward such programs.

The idea is an extension of the “Leave No Child Inside” campaign going on the past few years around the country and sponsored by assorted community groups trying to battle “nature deficit disorder” among children.

The tax proposal wasn’t intended to stir controversy and ire. A Sierra Club-funded study conducted in California apparently found that children who spent a week outdoors learning about nature and the environment acquired as much knowledge as six weeks of time spent in a classroom.

But it’s difficult to take seriously a tax that, despite all good intentions, implies there should be a penalty levied against fat, lazy kids — as if those two qualifications weren’t liability enough. (Full disclosure: The Game Guy is a card-carrying member of the Sierra Club.)

Such penalties tend to overshoot their intended target and cast a bad light elsewhere. (Additional disclosure: The Game Guy spends a lot of time playing games but he’s not fat — at least he doesn’t look that way in the dark.)

Perhaps a better approach would be to target the real source of the problem: parents. They’re the ones better positioned to turn off the gadgets — or not buy them in the first place — and push their progeny into the outdoors.