Almost anyone who went grocery shopping on Oahu over the past couple of days heard the cashier pipe up with a friendly reminder: “Do you want to purchase a bag?” they’d say, because July 1 signaled the start of a refinement to the existing plastic-bag ban.

That’s because of the enactment of Bill 59 the year before, which requires businesses to charge a fee on each one-time-use bag they issue to shoppers. This is Bag Ban 2.0; the original restriction, adopted by the Honolulu City Council in 2015, had a significant loophole.

The standard filmy “T-shirt bags” that had become ubiquitous in trash piles and scattered as litter were deemed single-use bags and banned. But customers could request a paper bag — or even a thicker plastic bag, considered “reusable.”

Some stores offered a refund to shoppers who brought their own reusables, but most did not have such an incentive and gave out the legal bags for free. So most people felt no great push to change their habits.

Now, any kind of single-use bag requires a 15-cent fee. This should work on two levels: as a reminder to those who customarily forget their bags in the trunk, and to cover the cost of the bags for the retailer who, up until the new law took effect, folded that expense into the price of merchandise for all.

This is much fairer: Those who depend on the store to issue bags will pay for them rather than passing the bill to others. It really should have been part of the original ban, but it’s good that the Council ultimately closed that gap.

In the interim, there’s been a fair amount of grumbling and eye-rolling at checkout stands. At this point, it might help for everyone to remember why Honolulu is bothering to do this.

The physical evidence of our collective wastefulness is on display in all its immense dimensions, but thousands of miles away from the view of virtually everyone. The so-called Great Pacific Garbage Patch, twice the size of Texas, floats between Hawaii and California, fed by plastics including much of the packaging cast-offs from our rampant consumerism.

And, according to a study published in March in Scientific Reports, the collection in the patch is “increasing exponentially and at a faster rate than in surrounding waters,” a poisonous element to marine life.

It’s unrealistic to expect there is any salvation from this mounting threat other than to cut off the plastic pollution at its source. There are limits to what the volunteer corps of beach-sweepers are willing or able to do.

For example, the local nonprofit Sustainable Coastlines Hawaii announced that it will not conduct the anti-litter project it has run for the past six Independence Day celebrations in Waikiki.

The annual Fourth of July “floatilla” of boats offshore brings revelers — with their soon-to-be discarded waste — to the beachfront. The educational efforts of the volunteers have successfully diverted about 500 pounds of debris that otherwise would have resulted from all the partying.

The costs of the cleanup approached $2,000 each year, and the group has reasonably concluded that this money could be better spent otherwise. Executive Director Kahi Pacarro has rightly said this work could be handled by the attendees themselves.

It’s time that they grow up and take responsibility for their own trash, as should we all.

Yes, it’s clear that American consumers everywhere have become lazy in the last 40 years or so that plastic shopping bags — and other packaging excesses — have been introduced. Nowhere more than in Hawaii, an island state with a disproportionately heavy impact on shoreline and marine pollution, should we get over that bad habit now.

Other states with a head-start on plastic bag bans have found it an easy adjustment. Bringing reusable bags to shop seems a small sacrifice to make, with a healthy environmental payoff.