WHAT links Brazilian knickers, beach reads, B&Q and a cross-bench peer? Now don’t get carried away. This is not the plotline for Fifty Shades of Green. It’s the economy, stupid (as they say).

Okay, so, knickers first. One in three women buy theirs from M&S – and with Valentine’s Day fast approaching, there will be a lot of chaps heading optimistically for the lingerie department, too. Knickers sales are fundamental to the company’s performance: a couple of years ago, sales of M&S Brazilian knickers (low-cut lace-trimmed pants) on a three-for-two offer were even credited with ‘saving’ Marks and Spencer.

The fact that said knickers are also sustainable – they are produced in the company’s first ‘eco factory’ – is not something that would necessarily sway an ardent lover, but it’s important. The factory, in Sri Lanka, is powered by a massive installation of solar panels and other renewable energy sources. It’s designed to consume less water and electricity and to be carbon neutral.

It is unlikely that factory would have been built to anything like such an ambitious standard of sustainability if it hadn’t been for Sir Stuart Rose, the then Chief Executive M&S, who pioneered ‘Plan A’ in 2007.

This is M&S’s commitment to ‘doing the right thing’ and it originally gave itself 100 pledges to reach within five years. By 2010 it had achieved 72 of them; it has now extended the goal to 180 targets by 2015 and aims to be the world’s most sustainable major retailer.

It is also unlikely that Sir Stuart himself would have come up with Plan A if he hadn’t been rushing through the airport bookshop and grabbed Al Gore’s book, An Inconvenient Truth, as a beach read. He told us this when he came to the University of York on January 29 to give the Cantor Lecture, entitled ‘The Sustainability Challenge for Big Business’, admitting that the book made such an impact on him that when he got home he immediately invited 100 M&S top executives to a screening of Gore’s film.

The following morning, 70 of them emailed him saying, “We’ve got to do something about this.” Plan A was born. Within three years they had made an extra £10 million profit, proving that doing the right thing makes you money, too. That’s not karma, baby; it’s sound economic sense.

When will our politicians ‘get’ this? The coalition government’s attitude is risible.

There’s the Chancellor saying, “We won’t save the planet by going out of business” as if the two exist in different continua and we are not dependent on this one world with its finite resources (I have always suspected he’s on a different planet anyway).

Al Gore himself has called George Osborne ‘seriously misguided’ and accused David Cameron of backing off the green agenda, saying, “Sustainable business prosperity has to be based on a view of the future grounded in facts.” And it isn’t only climate change we have to face up to: population growth is equally important. There isn’t enough to go round, and that’s before it hits 9 billion in the next two decades or so.

It’s a message no one in government, which is obsessed with growth, seems to want to hear. At a time when environmental sustainability has gone right off the agenda, it’s inspiring to hear a business leader of Stuart Rose’s stature not only tackling it, but calling for other businesses to lead the way.

So where does the cross-bench peer fit into all this? Lord Stern wrote the government-commissioned economic review of climate change, published in 2006. He’s just spoken out at the World Economic Forum, saying, “I got it wrong”. This is not good news. He now says global temperature rises, and their impact, are likely to be “far, far worse”.

As Stuart Rose concluded in his lecture, “The storm is gathering for our children and our grandchildren. Doing nothing is not an option. Doing the right thing is.”

Perhaps this is starting to happen. I’ve written a couple of times in this column about the decline of our bees, and the threat that neonicotinoid pesticides pose to their survival (and to our economy – it’s all linked). While the Government continues to drag its heels, three retailers – Wickes, B&Q and Homebase – have gone ahead and are refusing to sell pesticide products containing the chemicals.

It’s great to report some good news, for a change.