This is the small print with technicalities on how your carbon performance for waste was calculated. The score is improved by sending your waste to outlets with good environmental performance such recycling and energy from waste facilities (EFW) that use ‘Combined Heat and Power’ (CHP). CHP means that both electricity and heat (for heating homes, businesses, industry etc.) is recovered from burning general waste in special power stations.
The biggest improvement in scoring can be made by recycling. This is because every tonne of material not recycled and just disposed of has to be replaced by virgin material. For some materials such as metals, especially aluminium, the carbon impact of doing so is significant.
The largest emissions of greenhouse gases attributable to waste management come from landfilling mixed general waste. A large part of commercial waste in the UK is still sent to landfill and another growing part is exported for EFW recovery on the mainland. Relatively little commercial waste is sent to UK based EFW facilities. This is largely due to economic factors.
An assessment done by a leading UK consultancy firm confirmed that the landfilling of 10,000 tonnes of waste in the UK creates 2,462,216 kilogrammes of carbon dioxide equivalent (CO2e) and as such gives the worst score. Commercial waste that is exported to EFW facilities abroad that just recover electricity from this waste give the second worst performing option at 1,774,093kg CO2e for every 10,000 tonnes of waste. This is closely followed, at 1,512,555 kg CO2e, by EFW facilities in the UK that only generate electricity from waste.
Facilities that have CHP perform the best however UK based CHP EFW, at -351,421 kg CO2e, outperforms similar facilities abroad which perform at -89,883 kg CO2e. This is partially due to, amongst others, the impact of transporting waste long distances.
All commercial waste collected by Westminster City Council (WCC) is send to a local EFW facility with CHP, the only one in London so far. Transport distances from the city to this facility are minimal and the facility recovers the maximum in energy from the waste it treats. This means that the CO2e score from using WCC services for general waste performs far better that services offered by others.
Recycling your waste still creates CO2 since all processes which recycle materials require energy and some other processes also require a lot of (treated) water. Recycling does however save a large volume of CO2e since it avoids the need for virgin materials to be used. Nearly all virgin materials have a higher CO2e than those materials made through recycling.
Every tonne of material suitable for recycling that is recycled can save on average 366 kg of CO2e. This score can be improved by ensuring materials such as paper/cardboard and glass are segregated as source and not put into mixed recycling. Segregating mixed recycling costs more energy (and hence creates more CO2e) than materials already segregated at source.
Keeping food waste separate for food waste recycling avoids large CO2e emissions from decaying organic materials in landfill. Old electronic appliances (WEEE) contain many metals some of which are rare and are mined with big CO2 emissions. Recycling WEEE significantly improves overall CO2e score of your waste management performance.