Recycling has become a way of life in the UK. We’ve grown used to diligently dividing up our rubbish into different bins, and doing our bit for the environment.

On average, the recycling rate is now at more than 44 per cent among UK households, but in some areas it’s far higher. Wales leads the way – in 2012 it crossed the 50 per cent mark, with the majority of household rubbish now being recycled.

But is it all worth it?

Carbon emission savings

Inevitably, recycling causes some carbon emissions in itself – from the fuel used by collection lorries, to the energy taken to process the rubbish.

So, recycling is only beneficial in tackling climate change if the process emits less greenhouse gas than would be emitted otherwise.

That means that the net emissions saving will be different for different types of rubbish. For instance, you’ll probably save more on emissions by recycling materials which would otherwise have to be mined and transported across the world. Whereas materials easily produced in the UK are likely to have a smaller carbon footprint to begin with, so the net emission saving will be less.

A landmark study last year by academics at Southampton University highlighted this variation with a detailed breakdown. The researchers tracked the carbon footprint and carbon savings of dozens of material types for the entire process.

This graph shows their findings for a number of common types of rubbish. The bars show the net amount of greenhouse gasses that are ultimately saved (or emitted) for each tonne of rubbish that’s recycled.

Recycling aluminium creates by far the biggest savings of greenhouse gas emissions. Aluminium cans include most soft drink cans, but a lot of food cans are made of steel.

Recycling card and glass has a much smaller impact on reducing emissions. That’s not to say it’s not worth it – there is still a net saving, after all. But if you were to only recycle one thing in order to save emissions, drink cans would be the best option.

It’s worth noting that recycling process varies in different areas, so this study will not be identical in everywhere. However, it’s likely to paint a reliable picture of recycling in the UK.

Of course, recycling is about more than just saving carbon emissions. Campaigners cite other benefits, including reducing the amount of landfill, saving resources and avoiding injustices that are sometimes associated with producing new materials.

But here we are focusing on global warming, and the benefits of recycling in saving carbon emissions.

Offsetting your carbon footprint

Recycling may save carbon emissions, but how much does it offset your overall carbon footprint? You might recycle everything, but does that counteract the emissions produced by your car?

The first thing to note is that, in real life, this is not an either/or game. People are not going to stop heating their houses or travelling, so we have to look at recycling in terms of reducing your overall carbon footprint – rather than it being a direct trade off.

Just because you get an occasional flight, that doesn’t mean your recycling doesn’t still have a positive effect on reducing emissions. But how big an effect does it have?

Using the findings from the Southampton research paper, we calculated the impact of recycling a few specific items. The emission savings were then compared against the emission created by four examples: a 100 mile car journey, a short-haul flight, a long-haul flight and the typical UK annual household energy consumption. (Sources and workings are included at the end of this article).

We found that you would need to recycle more than 20,000 cans of baked beans – or around 8,200 Coke cans – to offset your carbon footprint for a return flight from London to New York.

And a typical household consumption for gas and electricity would be offset by recycling nearly half a million sheets of A4 paper.

Professor Ian Williams, who was one of the authors of the Southampton University research paper, told FactCheck: “Context is important – billions of metal cans and glass bottles are recycled globally every year yet there still is considerable room for improvement. We must continue to improve our household recycling rates if we are to keep carbon emissions to a minimum.”

Offset emissions by recycling Coke cans

Offset emissions by recycling wine bottles

Offset emissions by recycling cans of baked beans 

Offset emissions by recycling sheets of A4 paper 

Do we really need to separate rubbish into all those different bins?

In the UK there are two main methods of recycling collections: commingled and source-segregated.

Popular thinking may suggest that sorting the recycling out yourself, before it is collected, helps the process and is therefore better for the environment. But the truth is more complicated than that.

If your council asks you to separate recycling yourself, then not doing so could potentially hamper the system. But do we need that system in the first place?

Professor Williams told us there has not been an awful lot of research into which collection system is better. But councils’ request for residents to separate their waste could be more about politics than the environment.

“I think the reality is there is no perfect answer, but the evidence suggests there is not a significant amount of difference,” he said. “Commingled collections tend to be slightly more contaminated, but it’s made up for by the fact that they usually collect more rubbish.”

The overall difference is negligible because allowing people to mix their recycling could encourage more people to do it in the first place.

(It’s also worth noting here that councils can make a lot of money from recycling. For instance, it was reported a few years ago that East Lancashire councils made almost half a million pounds a year by selling on the waste).

How we made our calculations

• Net greenhouse gas emissions for each material (aluminium, steel, glass and paper) were based on the 2016 study from Southampton University.
• Numbers of unit per tonne were calculated based on the following weights: standard-sized aluminium Coke can weight provided by to FactCheck by Coco-Cola; weight of a standard-sized steel can of beans provided by Kraft Heinz; weight of A4 paper is based on standard 80gsm office paper; weight used for a glass wine bottle is the cut-off weight for “lightweight” bottles, meaning that around 30 per cent of bottles are lighter.
• Equivalent carbon emissions of the examples were calculated with carbonfootprint.com. Car emissions based on 100 miles in an EU 2016 FORD All New Focus, Model Year Post 2016½ 1.0 EcoBoost (125PS) with stop/start – 5 Door, A6. Short-haul flight based on an economy class direct return flight, London to Barcelona. Long-haul flight based on an economy class direct return flight, London to New York. Household energy bills based on Ofgem figures for typical household oil and gas consumption per year.