It's better to burn out than fade away. Kurt Cobain clearly thought so, quoting this famous Neil Young lyric in his suicide note, but then he obviously wasn't referring to the issue of greenhouse-gas emissions when it comes to the somewhat thorny cremation v burial debate.

For most environmentalists, it's actually better to fade away than burn out. Our lives, they say, already result in enough gratuitous combusting of fossil fuels. Much better, in death, to compost down as nature intended.

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.

So what to do? Burial at sea might seem a logical eco option, but the authorities generally frown on us choosing to become fishfood: just 50 or so non-navy sea burials are granted each year for the UK's three licenced locations (Newhaven, Sussex; The Needles, Isle of Wight; and Tynemouth, Northumberland). However, woodland burials are becoming an increasingly popular option, as is the use of fully biodegradable coffins. There are now about 200 woodland burial sites in the UK (see www.naturaldeath.org.uk) which offer families an alternative to cemeteries or crematoria. Managed either privately (often by a farmer) or by a local authority, these burial sites are left unmarked or are marked by the planting of a tree or wild flowers. Any coffin used must be made from a fully biodegradable material such as cardboard or wicker, or a cloth or drape can be used instead.

While many find much comfort in this naturally-minded option, there is a question about just how sustainable it can be to offer everyone who can afford it their own piece of pristine woodland in perpetuity. One of the reasons cremation superseded burials in the UK was because available space had greatly diminished over the decades. After all, the post-war drive to get more people to consider cremation included the slogan "Save the land for the living". Recognising the continuing pressure for space, a House of Commons select committee inquiry into cemeteries in 2001 urged for multi-burials to take place in the same site. It seems this taboo will have to be broken before a truly sustainable burial option is found in this country.

Eco alternatives to burial and cremation are still being sought. Just last week, a Swedish town made headlines when it announced it was set to try freeze-drying its dead into brittle, compostable remains using liquid nitrogen. And solar-powered crematoria have been proposed to help save the millions of tonnes of wood burnt each year cremating India's dead. But while we wait to learn whether these are viable options, it seems that being buried in a modest, fully biodegradable coffin remains the option that is least harmful to the environment.

You say ...

Jocelyn Rose, Kirkcudbright

I'm a bit worried about these new-ish "green" burial sites that farmers are setting up on land they don't use. What happens once the site is full and there's no more money coming in? Who's going to maintain the site?

Angela Latham, West Sussex

I don't want to choose between cremation and burial in the ground. I want an air burial - the birds can have me. But how to? What do the Parsee British do to have their traditional flight of passage?

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