Food waste recycling key to reducing carbon emissions, says ZWS
The Carbon Metric is a tool designed by Zero Waste Scotland (ZWS), the Scottish Government-funded circular economy organisation, to measure the ‘whole-life carbon impacts of Scotland’s waste’, meaning the amount of carbon emissions that have been produced from resource extraction, through manufacturing to the waste management stage.
The official household waste and recycling statistics for 2017, published this week by the Scottish Environmental Protection Agency (SEPA), reveal that Scotland achieved a household waste recycling rate of 45.6 per cent, an increase of 0.6 per cent on the 2016 figure. The amount of household waste to landfill has dropped by 2.2 per cent and, for the first time, more waste was sent for recycling (1.12 million tonnes) than to landfill (1.11 million tonnes).
Applying the Carbon Metric to these figures shows that 5.86 million tonnes of carbon dioxide equivalent – an aggregate statistic incorporating various different types of greenhouse gas emissions, based on how much global warming each gas will cause – were produced from Scotland’s household waste in 2017, or 1.09 tonnes per person.
Integrating this metric into official waste statistics potentially allows for a more nuanced approach to the impacts of waste and recycling than simply measuring by weight, taking into account the wider environmental effects of different types waste.
Currently, official recycling rates in the UK come from the tonnage of material collected, meaning that local authorities can increase their recycling rates by focusing on collecting heavy materials like garden waste, thereby increasing their overall tonnage – something Simon Hann of Eunomia Research and Consulting referred to as ‘gaming’ the system. However, as ZWS explains, the waste that is the most carbon intensive (produces the most carbon emissions in relation to the amount of energy consumed over its life cycle) is not always the heaviest (and thus the most targeted by recycling schemes).
In its Carbon Metric Summary Report, using 2014 and 2015 data, ZWS shows that the five most carbon intensive materials make up only nine per cent of Scotland’s total waste by weight – but they contribute nearly half of total carbon impacts. Food waste is the most carbon intensive waste material, producing 22 per cent of waste carbon impacts despite only making up five per cent of Scotland’s total waste.
‘The fight against climate change begins at home’
Data from ZWS also shows that while household waste only makes up 25 per cent of Scotland’s total waste, it is responsible for 55 per cent of total waste carbon impacts, underlining the importance of reducing and recycling all household waste.
Iain Gulland, Chief Executive of ZWS, explained: “Our Carbon Metric, which for the first time now forms part of Scotland’s official reporting on waste, shows the crucial role householders can play in preventing waste and recycling more of their waste, particularly food waste, and how significant an impact that will have on reducing our climate changing emissions. This report gives extra resonance to our message during Recycle Week 2018, when we are urging Scots to recycle as much as they can from all around the home.”
SEPA’s Chief Executive, Terry A’Hearn, added: “Communities and businesses in Scotland are becoming increasingly aware of the impact of waste on carbon emissions and climate change, and today’s figures reflect this. But we can’t be complacent.
“We need a 21st century environment protection agency to ensure Scotland lives within its means – and to help society tackle sources of pollution, over-use of natural resources and major environmental challenges such as climate change. The Carbon Metric is a useful tool which will help us target our efforts”.
In August, the Environmental Services Association (ESA) gave its backing to a move away from national weight-based targets, calling for ‘smarter recycling measures’ including using carbon as a way to measure environmental performance.
Resource recently published Eunomia’s 2018 Carbon Index, which ranks UK local authorities by the reduction in carbon emissions achieved through recycling, as an alternative to measures based solely on tonnage. Simon Hann writes: ‘Consider an authority that collects a lot of green waste for composting, for example, but rather less dry recycling. In tonnage terms, it may have a high recycling rate, but recycling metals, plastics and paper brings about greater carbon savings than does composting green waste, so such a council may occupy a rather lower rank on the Carbon Index.’