Metro Parks and the Tacoma-Pierce County Health Department think they have an offer Tacoma’s leaders can’t refuse.

Want to give smokers a new incentive to quit? Tell them they can’t light up in a Tacoma park.

Want to prevent children from getting addicted? Make sure a trip to the neighborhood sprayground doesn’t include the sight of someone taking a drag.

Want parks to look nicer? Stop cigarette butts before they start.

The proposed smoke ban for Tacoma’s parks could accomplish all these things – in theory. Reality is another story.

There’s nothing wrong per se with using the law to encourage healthy behavior. The codes are full of attempts to establish or endorse societal norms. But laws should offer some reasonable hope of solving the problems they purport to address. An all-encompassing ban on smoking in parks falls short.

Smokers who have been kicked out of offices, restaurants and bars yet still puff away aren’t going to kick cigarettes just because the neighborhood park is now off limits.

Kids won’t take up smoking because they saw some shady character at the park smoking. They take up smoking because they see their friends, classmates and loved ones doing it.

Littering? That’s already against the law, yet parks are still strewn with bottles, cans and hamburger wrappers. Tacoma officials might as well tell people not to picnic in the park if they’re serious about cutting down on the amount of trash on the loose.

Trying to legislate smokers into a corner – quite literally – is an overreach. The people who would be disproportionately affected by a park smoking ban are the homeless, many of whom smoke and spend a good deal of their days in parks.

When Washington banned smoking from public buildings, it had solid public health reasons for doing so. Being trapped in a confined space with someone’s else toxic plume has proven health effects.

Absent proof that secondhand smoke wafting across the Point Defiance Park duck pond poses a similar threat, the case for a sweeping smoking ban is hard to make.

But there’s an exception.

Kids are an especially vulnerable population, and they aren’t likely to leave the monkey bars just because a group of smokers is congregating nearby.

The city should consider what Portland has done. That city bans smoking within 25 feet of play areas – the same perimeter Washington law sets for the entrances to public buildings.

The City Council could also outlaw smoking in pocket parks where escaping secondhand smoke would be nearly impossible. But it should stop short of an all-but-unenforceable all-out ban.