'According to the Federation of British Cremation Authorities, there were 424,956 cremations held in the UK in 2004. This figure represents 70.8% of all deaths. Consider that a cremator needs to operate at 760-1150C for 75 minutes per cremation and it's easy to see how much energy is required. In fact, a cremator uses about 285 kiloWatt hours of gas and 15kWh of electricity on average per cremation - roughly the same domestic energy demands as a single person for an entire month.
Aside from the considerable amount of greenhouse gas emissions this creates, cremation is also responsible for 16% of the UK's mercury pollution (via our dental fillings), according to the Environment Agency. The industry has been told that all 650 crematoria must halve mercury emissions by 2012, but, ironically, one way to do this is to cremate at a higher temperature, thereby leading to more emissions.
Then there are the materials used to make a coffin. Wooden coffins are either made from solid oak or pine, or more likely (89%, in fact) from veneered chipboard, which is bonded with a formaldehyde resin. All of which, of course, will end up being burnt and entering the atmosphere.
But these materials also enter the ground if burial is the preferred option, as do embalming chemicals - also formaldehyde-based - which can, over time, enter the watercourse. So even in death we're not let off the hook when it comes to considering our environmental impact.,
From the Guardian 2005.