Composting massively reduces greenhouse gas emissions compared to landfill

At a recent meeting with Local Government Mayors and CEO’s, a claim was made that transporting organics by truck to a distant compost facility (in this case 150km away) would emit more greenhouse gases than landfilling it locally. Thinking that the carbon forcing factor of methane from landfill (25 times CO2) would render that claim incorrect, I thought I should go back and check the maths.