What's wrong with burning our waste (NCE, 4 May)? How about up to 2.8 tonnes of CO 2, NOX, SOX and ash for each tonne of waste processed, just for a start?
Energy arguments favour anaerobic digestion with methane recovery for wet putrescible waste, and materials recovery for incombustibles such as glass and metals.
Paper and wood can be burned - with suitable emissions controls - for electricity generation and heat recovery.
Plastics are more difcult: they have a high caloric value and energy recovery is easier than materials recovery, but they are essentially a fossil fuel.
All of this requires separation of waste, preferably at source.
Yes this is a challenge, but one that we as engineers must help society to address rather than advocating an easy but flawed quick fix.
William Powrie (F), Chair, Defra New Technologies Demonstrator Programme Advisory Committee, wp@soton. ac. uk