Mayor Bill de Blasio is asking you to join him in changing your life for the betterment of this earth.

He, for example, recycles and composts. He tries not to use plastic bags. Just don’t ask him why he takes a city SUV most mornings on a 12-mile trip from Gracie Mansion to his old 9th Street YMCA gym in Park Slope.

Since the early days of his administration, de Blasio has regularly spent mornings, including weekdays, working out at the gym a borough away from his new home, necessitating police protection and an SUV escort. He has continued doing so despite criticism that the long gym detour sometimes cuts into his schedule.

He has kept riding a stationary bicycle in Brooklyn, even when police union protesters set up shop outside the gym during contract fights. And he says he’ll keep riding in his regular gym despite the current criticism after he suggested on “The Brian Lehrer Show” on WNYC radio last week that New Yorkers should “change their own habits” to combat President Donald Trump’s apathy on climate change, even while he himself continues the car trips.

Personal choices can help preserve the environment

The mayor’s certainly right that there’s plenty concerned citizens can do.

One could eat less red meat in favor of chicken or other proteins. Beef, for example, constitutes some 5 times as much in greenhouse gas contributions as compared to chicken.

If possible with time constraints, you could skip the flight for a train or bus, given that one round-trip Denver-NYC flight can amount to nearly a year’s worth of car emissions.

Right here at home, you might take the lead from GreeNYC, the city’s own public education program meant to increase city sustainability.

GreeNYC’s website includes tips for how to seal leaks, opt out of wasteful junk mail, or participate in the city’s growing composting program.

GreeNYC also advises the use of public transportation, as MTA riders “keep 700,000 cars out of the city’s central business district and 400 million pounds of pollution out of the air.” Some critics have suggested that de Blasio make his gym commute by subway for this reason — plus it might also give him a better sense of commuter woes and convince him to more forcefully advocate and negotiate for state solutions to fix the system.

The mayor says the ride to the gym allows him to work efficiently on the people’s business, and the ride itself takes place on examplars of the city’s hybrid car fleet.

He has also simply argued that it’s a way to stay “grounded” and in touch with his old community.

Those urging de Blasio to take a daily hour-long public transportation trip to the Y aren’t really being fair. No New Yorker should wish a commute that involves taking a bus to the Q train followed by another bus on a fellow New Yorker. And while the average straphanger can kill a half hour reading newsletters (like this one) and tweeting angrily at the MTA, the mayor has other things to do with his time, hence the speedier SUV.

Action doesn’t need to be complicated

But there’s a much simpler solution familiar to anyone who has hopped apartments: find a new gym.

Within a five block radius of the mayor’s digs at Gracie Mansion there are two Crossfit locations and a YMCA-like Asphalt Green campus with pools, bikes, treadmills and sports facilities galore.

Denizens of the Upper East Side would surely enjoy the strange experience of seeing the mayor’s giant frame folded on an exercise mat or sweatily traversing the locker rooms, an activity only granted to the Prospect Park Y’s members. He can still go back once in a while for a visit.

Mostly, such a switch would be just the kind of little sacrifice de Blasio is rightfully urging New Yorkers to consider for the good of the environment. Those actions aren’t “cheap symbolism,” as he said of the YMCA flap on Friday. Like any repetitions, gym-based or otherwise, they add up.