At the weekend the Guardian was running a climate special. In one article, they asked climate experts what they were doing personally to cut their own footprint. This is always a question that makes me feel guilty.

I like to think I live a (relatively) low carbon lifestyle: I work from home and Mrs K commutes via cycle and train, we usually holiday in the UK, my main hobby is cycling, we’re on green tariffs for electricity and gas, we’ve massively boosted the insulation of our draughty Victorian house, and we’re big believers in second hand books, clothes and toys.

However, there are many ‘minuses’ in eco-terms: we’re omnivorous, we have 3 kids, we own a diesel car and we are known to fly off to far flung parts every few years.

As regular readers will know, I believe in pragmatic environmentalism rather than green puritanism, but I am also very aware that I can’t simply hide behind the ‘good’ I do professionally and politically to offset a profligate lifestyle.  But charting a middle course can be difficult, it’s all too easy to drift back to a high carbon lifestyle – or not start on it in the first place.

I’ve stumbled on a rather effective life hack which I call ‘Just One’.

In the aftermath of Blue Planet II, I pledged to pick up one piece of someone else’s plastic litter every day – on the grounds that this material is the most likely to end up in the oceans. Over time, I found that most days I pick up 6-12 pieces and am much more likely to go on major litter picks. I organised a litter pick yesterday and we filled 17 rubbish sacks with litter, much of it plastic. But it is that ‘one every day’ that keeps the process turning over, week in week out.

Likewise, a few months ago I started ‘Meat-free Monday’ in the house (I’m head chef). This has kindled a culinary interest in what to do with vegetables and I’ve now found that I’m preparing 2 or 3 veggie main meals a week and it doesn’t feel like a sacrifice. As we largely eat fish and chicken the other days, our red meat consumption has plummeted – but I can still have a dirty burger or a steak ciabatta when I feel like spoiling myself. But it’s that bottom line of ‘one day every week is vegetarian’ that got me started and keeps the whole thing going.

This ‘just one’ approach can be used to initiate behaviour change in the corporate environment too. I often conclude employee engagement sessions with a pledge card where each delegate chooses just one eco-idea to take away and run with. If you want to be a Sustainability Ambassador at Interface, you have to choose, develop and deliver one sustainability project in your area of work. The CEO of another client instructed board members that they each need to take one Sustainability/CSR issue to champion – their choice of issue, but they will be held to delivering on it.

This ‘just one’ approach is very powerful in Sustainability. It brings simplicity and focus in a world where complexity, scale and scope reign supreme. It takes away that feeling of hopelessness, lowers mental inertia and creates momentum. Try it – on just one thing first!