Mark Whitby need not have wrestled with his conscience over burning tree prunings (NCE 9 November). If they had been shredded and spread on his garden, bacterial action would have caused them to decay, releasing their carbon in the form of CO 2just as surely as if they had been burned.
If any had decayed in the absence of oxygen, much of its carbon would have been released as methane, which is alleged to be 20 times worse than CO 2with regards to global warming. Keep the home fires burning!
Roger Evans. firstname.lastname@example.org