There was a time when I walked down the street several paces behind my partner – not out of deference (though he has suggested it), but from the hope of dissociating myself from him.

The source of embarrassment was a litter-picker I rashly gave him after he'd lusted after one I bought for my father, who was having difficulty bending to collect junk blown into his garden. Within days – hours – this mechanical claw was being put to use on the playing fields opposite our flat. It was as if he were auditioning for a parkie's job, not realising such posts went out with Thatcher.

Needless to say, I rarely joined him. A few weeks ago, however, he coaxed me into a tidy-up mission in the local bird sanctuary, where plastic bags were blooming like daisies, turning a leafy oasis into a forest of tattered plastic flags. In the face of a wasteland of rubbish, caught in trees, grass and fences, my self-consciousness fled. I even wished I had my own litter-picker.

The news that the Scottish Government is this week beginning a consultation into making supermarkets charge a minimum of 5p for each plastic carrier bag shoppers use is thus a very cheering step. If adopted it won't solve all our litter problems, but it's a strong statement of intent in the battle to reduce the plastic tide that washes over our verges, gardens and parks each day. Since a similar project in the Republic of Ireland saw plastic-bag litter drop by 95%, and 90% of shoppers start to use long-life carriers, the idea augurs well for our environment, and our consciences. So too for charities, who'll be the beneficiaries of all those 5ps.

Inevitably, though, there are grumbles. Sceptics challenge the idea that consumers should be charged for bags, and ask why, if they absolutely must pay, they cost so much when they're so cheap to produce? Green MSP Alison Johnstone has a good answer: "I ask those who oppose this policy to question whether there is such a thing as a free plastic bag. And who picks up the bill for littered cities and polluted seas?"

Of course it's annoying having to fork out for a bag when we've been too forgetful, lazy or heedless to take along our own. And for those on low incomes, this might feel like an additional burden, a tax they do not deserve. But the problem of plastic waste is so serious and so widespread that tough measures are required. Not only is plastic an unsightly blight on our landscape, but it is a pollutant, poisoning rivers, lochs and seas. For wildlife, it is dangerous and often deadly, from the birds and animals that choke on it, to the toxic waste absorbed by creatures that then become part of our food chain.

In the face of this ever-growing threat, what's required is nothing less than a cultural volte-face. After a century of living as if we own the planet, we need to reverse our addiction to the quick and easy disposable life, and embrace the second-hand and hand-knitted, the shabby, crinkled and old.

I speak as one who is far from perfect. One reason I cringe at being seen picking up litter is the idea that I'm some kind of eco-saint. If only. There is, however, a phenomenon that has made me a bit less thoughtless, and gives the idea of reducing the mountain of plastic we use an added sense of urgency.

The Great Pacific Garbage Patch is a swirling island of debris, roughly twice the size of Hawaii, composed of plastic discharged into the sea from every part of the world. One of the worst culprits, apparently, are cruise liners, which dump around eight tons of solid waste every week, much of which eventually finds its way into this dead ocean mass.

A photo of a dead albatross found there, whose stomach was full of bottle lids, was enough to make me start rethinking my plastic habits. As yet I haven't gone so far as New Yorker writer Ian Frazier, who invented a specially-long implement for winkling bags out of trees, but that's only because for the moment there's more than enough to deal with at ground level.