Reducing food waste helps, but it's going to take systemic action to tackle climate change

© Stefan Redel – 123RF.com

The problem is that little actions typically only make a little difference. While there are rare examples of small gestures from individual people leading to big changes – think of Rosa Parks’ decision about where to sit on the bus – unfortunately for the do-gooders out there. Many people recycle, but it’s a lot more difficult to spark a recycling revolution.

And so, it’s understandable if the Tesco approach to greening the planet (“every little helps!”) doesn’t feel like it’ll achieve the deep cuts in greenhouses gases needed to avoid dangerous climate change – because it probably won’t. If, for example, you eat a Western diet, cutting down on meat can reduce your carbon footprint: vegetarian diets produce about 20-30% fewer greenhouse gases than their meat-eating equivalents. Problem solved? Unfortunately not.

For most people living in Europe, your diet makes up say 10% of your carbon footprint, so that 30% greenhouse gas saving sums to about a less impressive 3% cut in your total carbon emissions. While that may be an important and achievable 3% reduction, we’re going to have to do more than that – especially if these changes in our behaviour have unforeseen consequences.

The system fights back

Imagine if providing recycling bins actually increased waste. That’s what they found in the bathrooms at the University of Washington. Researchers measured how many paper hand towels people used and threw away under two scenarios, one where there was a recycling bin available, and one where there wasn’t. They found – perhaps surprisingly – that where people could recycle, they wasted more.

This is an example of a “rebound effect”, where a behavioural change (for example, encouraging recycling) has unforeseen side-effects which reduce the hoped-for benefits. In this case, where there were recycling bins, people felt it was OK to use more paper – it was, after all, being recycled. And this isn’t an isolated example. We recently analysed the impacts of efforts to reduce food waste in the UK, and found a worryingly similar pattern.

Food waste is a huge problem. UK households waste about a third of their food and this waste produces a lot of carbon – eliminating household food waste would be equivalent to taking one in four cars off the road. Recognising this, there are a growing number of initiatives to reduce food waste, by reducing confusion about best before dates, encouraging people to plan their meals, or by redistributing it to the hungry.

I wholeheartedly support these initiatives (we even served food waste at my wedding), but their benefits are tempered by rebound effects. When people waste less food, they also save money from the food they didn’t have to buy (and waste). This extra money doesn’t disappear. Instead, it’s spent on other things: be that travel, furniture, or Pokémon Go. And it turns out that when we take into account this rebound spending, it reduces the benefits in terms of greenhouse gases by as much as 60%.

What this tells us is that even the best intentions are constrained by the unsustainable socioeconomic system that we all live in. To dramatically reduce greenhouse gases we still need people to take the little actions, by wasting less or using public transport – but we also need to push for systemic change: we need to decarbonise the whole economy, so that when rebounds occur, they work with us, not against us.

Fix the system

So, what should we do? Our food waste example provides a few clues. We analysed the environmental impact of food waste across the whole supply chain and found that because the UK imports half of its food, the impacts in other parts of the world are disproportionately important – in fact, almost two-thirds of the UK’s food-related greenhouse gas emissions occur abroad.

To fix the UK’s food system, we first need to see it as a system – there are huge opportunities to reduce greenhouse gas emissions by fostering sustainable farming practices, not just in the UK, but also in the developing world. To make this happen, we need to work with the levers which move the system – petition to make government policy more outward looking, or boycott and shame companies whose products are associated with deforestation or other greenhouse gas-releasing practices.

Admittedly, trying to move the system is more daunting than behavioural change at home, and ultimately, we still need to do both. It’s important to organise political sit-ins and boycotts, and make politicians aware if you disagree with the disbanding of the Department of Climate Change or government support for fracking, for example – but also don’t forget to turn off the lights when you’re done.