Carbon and climate change. The words have become irrevocably linked as we’ve learned that we must lower emissions to avoid catastrophic global warming. But transmuting words into action has proved rather difficult. Scientists are reporting unexpected, record rises in greenhouse gases (a six per cent jump in global emissions between 2009 and 2010); the UN climate talks again descended into a farce of ineptitude; and senior environmentalists including Jonathon Porritt and Caroline Lucas point out that the ‘greenest government ever’ ‘is on a path to becoming the most environmentally destructive government to hold power... since the environmental movement was born’.

And what, you may ask, does this have to do with waste? Well, quite a bit potentially, as efficient management of resources and waste could have a drastic impact on worldwide emissions. Indeed, before the ill-fated 2009 UN conference in Copenhagen, a Bureau of International Recycling (BIR) report claimed the global recycling industry delivers annual CO2 reductions of 500 million tonnes. This was a conservative estimate, it said, equal to almost two per cent of global fossil fuel emissions, which resulted from reprocessing 600 million tonnes of commodities to deliver nearly half of the raw materials needed for global manufacturing.

These savings result predominantly from avoiding the extraction and processing of raw materials (recycling a tonne of aluminium, for instance, releases only five per cent as much carbon as refining the virgin stuff), but waste is still responsible for emissions. According to the coalition’s 2011 ‘Carbon Plan’, the industry generates around three per cent of the UK’s carbon emissions – 89 per cent of waste emissions come from landfills where biodegradable wastes give off powerful methane. Because we’ve become more of a ‘recycling society’, these emissions dropped by 70 per cent between 1990 and 2009, and more recycling (and, crucially, more prevention) would keep moving the resource industry as a whole into carbon positivity.

‘Carbon’ is mentioned 40 times in Defra’s recent waste review and an impressive 60 in the accompanying 20-page action plan, so the rhetoric (as always) seems to be there, but what about the action?

Well, the main concretely carbon-related action is the development of a ‘carbon metric’ to sit alongside existing weight-based reporting. A spokesperson for Defra told Resource: “The aim of the carbon metric is to raise awareness of this way of measuring the impact of the different waste management options, and to build confidence in the tools to do this. We believe a carbon metric can more accurately reflect the environmental impact of different waste management options, and of prioritising different materials, than simply the weight of material.”

The spokesperson continued that the concept is similar to the Scottish Government’s carbon metric (of which more in a moment), and is based on the same underpinning work by WRAP. Defra plans to introduce the metric at some point in 2012, but has no plans to use it to set targets at this time, preferring instead to stick with the weight-based targets favoured by the EU.

Many in the recycling industry have long argued that weight-based targets are perverse, resulting in attention being paid to heavy waste, as opposed to waste that has the highest environmental impact. Materials such as plastic and textiles result in a great deal of carbon, but – plastics especially – have a poor volume-to-weight ratio, meaning they haven’t been targeted as effectively as possible.

Asked about the European Commission’s (EC) penchant for weight-based targets, an EC spokesperson reported: “Using a weight-based indicator is the most appropriate approach to measure the progress accomplished with ‘verifiable’ and solid methods. It is also a good proxy to derivate the possible impacts on greenhouse gas emissions.” Whilst acknowledging the potential of waste management to reduce greenhouse gas emissions, the spokesperson explained that there are no current plans to develop carbon-based targets as: “Proper waste management has multiple beneficial effects on resource use and on the environment (biodiversity, water, air, soil, preservation of resources, etc), climate change being one of these benefits – but not the only one; [and it] might be delicate to fix this kind of targets for practical reasons (more difficult to measure/verify).”

But the EU’s desire to continue prioritising weight hasn’t stopped one country from forging ahead into new territory and basing targets on carbon. Environmental Analyst Kimberley Pratt of Zero Waste Scotland explains the Scottish Government’s approach to this matter: “There was an overwhelming response to [the Zero Waste Plan consultation] that it would be better to measure something that was closer to environmental impact than tonnages... There’s a lot of information available on carbon, so it’s the most accurate indicator that we could use. And we can use it as a proxy for environmental impact in most cases.”

Scotland’s resulting carbon metric – which has been available since March and is now the basis of Scotland’s domestic targets – is based on a lifecycle approach and looks at the environmental/carbon benefit of sending one tonne of material to recycling rather than to landfill. We’ve often been advised to view lifecycle assessments with a bit of caution (see Resource 59's weighing in on LCAs), and carbon is a notoriously slippery molecule to measure (hence our scientists’ consternation in the picture there), but Pratt points to Scotland’s adherence to the ISO14040 and PAS2050, noting: “I think we can be confident that we got the numbers as accurate as possible from a scientific point of view.”

The calculations include CO2 equivalent emissions generated through extraction of raw material, manufacture, transportation, distribution and disposal. These calculations have resulted in weightings between 0 and 100, factors to be applied to each material type as it is collected and diverted; textiles, for example, have the highest weighting at 100.00, while aluminium cans and foil have the impressive weighting of 65.87 and food and drink the surprisingly low figure of 4.35.

Considering organic waste rotting in landfill is the waste industry’s biggest carbon culprit, you’d expect food waste to have the highest weighting; asked about this low figure, Pratt explains: “The carbon metric at the moment looks at the environmental benefit of sending one tonne of material to recycling rather than to landfill. Closed-loop recycling usually has a higher environmental benefit, but you can’t close-loop recycle food – you can’t eat compost – and that means that you don’t get the savings from avoided production emissions... The final calculation also takes into account the weight. Food is quite heavy, so that will automatically pump the food numbers up.”

What’s more, as is common with lifecycle assessments (but not the coalition’s ‘Carbon Plan’, evidently), the Scottish carbon metric excludes biogenic emissions (both carbon and methane) on the grounds that biogenic carbon is on a much shorter, natural cycle and not contributing to man-made climate change in the same way as fossil-fuel derived carbon. While this is a largely unquestioned approach, Dominic Hogg of Eunomia, for one, has called for a change, “unless we take the absurd assumption that the climate responds differently to biogenic and non-biogenic CO2 molecules.” (Pratt does insist, though, that including biogenic carbon in this instance wouldn’t make much of a difference.)

Pratt’s use of the phrase ‘at the moment’ earlier indicates that the carbon metric is a work in progress, though, which will be refined with time. “One of the gaps in the metric at the moment is there are some things that there isn’t any available data on, so we haven’t been able to include those materials”, Pratt points out. Automotive batteries, fluorescent tubes, paint, and incinerator residues have been left off the list, although those aren’t terribly common.

What’s more, due to a lack of Scotland-specific information on waste’s final recovery route, the metric assumes most materials go for closed-loop recycling rather than open-looped (apart from the aforementioned food and garden waste, as well as textiles, assumed to be reused, and glass, which has two weightings depending on how it’s reprocessed). The Carbon Trust’s peer review of the metric points to this as an area to be improved upon, noting it’s ‘important to distinguish between the two routes as best as possible’.

Pratt says the Scottish Government “might consider” revisiting the metric to take different end-of-life processes into account, but points out: “This is the first time anyone in the world has attempted to do something like this and we wanted to take the process in manageable steps rather than trying to do everything at once. But in the future, it’s hoped that we’ll start measuring things like reuse and prevention in terms of carbon, and that will become part of the same agenda as well.”

And, as reuse and prevention are surely the ultimate ways to avoid emissions, achieving that would certainly be a breath of (non-carbon-laden) fresh air! Watch this space.