A recently published article in www.sciencefocus.com reads:-

It takes 285kWh of gas and 15 kWh of electricity to cremate a single person.  The CO2 this generates is roughly the same as an 800km car journey. Cremation also accounts for 16% of the mercury pollution in the air, from dental fillings.

But burial pollutes too.  Formaldehyde used in embalming, and in the chipboard veneer used in 89% of coffins, eventually leaches into the groundwater.  Concrete vaults also take a lot of energy to manufacture.  The greenest option is currently to forego embalming of the corpse and opt for a woodland burial in a biodegradable cardboard or wicker coffin.  See my next tab on natural burials.

‘We Need to Talk About Death‘ is a series of three radio programmes available on podcast from BBC Radio 4.  In December 2016 Joan Bakewell produced these interesting 20 minute episode that discuss the process of death itself, pain and other matters surrounding the end of life.  Worth a listen if you want to know more.