Why carbon could be a more beneficial metric than recycling rates

Posted by Chris Hoy on 4 January 2017

Why do we recycle? I believe fundamentally it’s to improve the environment by saving resources and reducing emissions. As such, tracking of performance is equally vital, especially as I think we should be constantly trying to improve / lessen the impact we have on the planet.

Recycling rates were ideal for monitoring performance in the early years of waste data as recycling developed in the UK but they are now little more than a blunt tool. We now have greater information and understanding of the materials collected, what process it goes to and through, and the impact these have on the environment. So why not develop a smarter method of assessing overall waste management performance?

Changing metrics?

There is a growing swell of opinion on the matter, with LARAC recently suggesting that a tonnage-based measure is not ideal and that other metrics should be considered. Personally, I think carbon would be the best alternative metric, given it’s typically used as a proxy for environmental performance and the science and understanding is already well in place. Carbon and climate change are well known to the public, and other tools already use carbon as a key indicator of wider environmental impact, so I see the future being one where an ‘appraisal system’ for current services, planned changes and future strategies is based on these well understood concepts.

Recent Defra data for England has shown a drop in recycling rates, with various reasons put forward for this such as, seasonal impacts on green waste, austerity impacts on service provision, tighter recycling materials standards, increasing contamination levels and the introduction of chargeable garden waste schemes. All these have an impact but I believe the ever reducing budgets available to local authorities and the challenge this places is their waste management service is the most fundamental of the underlying issues.

If we moved to a carbon-based approach it would allow authorities to use their limited budgets to target material that have the greatest environmental impact and as such achieve a greater positive environmental impact per pound spent. Surely that is where our focus should be, and not on heavy materials that give us a few recycling percentage points?

Making it happen

Moving to a carbon-based approach would also allow a more holistic approach to decision-making to be taken, considering not only the recycling, food waste and garden waste but also how residual waste is managed. Ricardo Energy & Environment’s innovative carbon league table, which, for the first time, ranked local authorities according to the carbon impacts of their complete waste management service, including the fate of residual waste, showed that weight-based performance and carbon-based performance do not always align. For example, authorities that were able to avoid landfill and generate energy from the residual waste were in some cases able to achieve significantly higher carbon rankings than authorities with higher recycling rates.

Local Authority Carbon League Table

Ricardo Energy & Environment has worked with a wide range of authorities, private sector companies and government organisations to assess the carbon performance of their waste services, and of their planned changes. Many of our clients are clearly committed to reducing their carbon impacts and have set ambitious reduction targets, so moving to a carbon-based metric would seem a logical progression and one that would reward these efforts, rather than limiting their view to what will protect or enhance our recycling rate, potentially to the detriment of the environment!

To support our clients, Ricardo Energy & Environment have developed a simple Excel tool to estimate the carbon impact of an authority’s waste service (contact us for a demo), including direct and indirect emissions and carbon benefits, associated with a Council’s collection, recycling, transport, processing and disposal operations. The tool is based on publically available carbon ‘factors’ and designed to allow the client to quickly model their own scenarios without any complicated or expensive lifecycle tools. Our experience from developing such a tool leads us to think that developing a whole waste service carbon based metric is certainly possible and probably sensible as the complexity of the solutions and the pressure on services increases.

Who will drive this shift?

Our project experience has shown that using a carbon-based metric and making service change decisions on environmental grounds also leads to additional benefits, such reduction in costs or other factors such as vehicles on the road or improved recycling rates. So it really is a no-brainer that we need to embrace a new tool, enabling better comparisons of services and authorities, one based on carbon. But who will make this happen? Some authorities are already helping to inform their decisions by using such assessments, but it is far from the norm, and we have no policy direction from Defra (or WRAP) suggesting this will happen. But given the increasing attention being placed on extended frequency collections, concerns about recycling contamination, and the ongoing debates about the role of energy recovery in sustainable waste management shouldn’t a carbon-based system of assessment be promoted centrally, and soon?

I believe developing a new metric to assess waste that shows the impact on the Earth, such as carbon, could be a stronger message for the public to get behind and thus drive further improvement in their engagement, their commitment and their appreciation of the services on offer. And if the public like it, then perhaps the politicians will too? Watch this space......

If you would like to know more about carbon impacts and your waste service or see a demonstration of our carbon model please get in touch.


Chris Hoy is a senior consultant within Ricardo Energy & Environment’s Resource
Efficiency and Waste Management team. He specialises in conducting
environmental and carbon analysis to support strategy development, business
cases and option appraisals. Chris has developed carbon models for the Welsh
Government and run training workshops for Zero Waste Scotland on producing
carbon management plans and utilising the Carbon Metric.

Chris Hoy 
Senior Consultant
01235 75 3408



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