SCOTS' current way of life is "deeply, deeply unsustainable" and has to change dramatically as part of global efforts to reduce greenhouse gases, according to the head of the Scottish Environment Protection Agency (SEPA).

In an interview with The Scotsman, Dr Campbell Gemmell, the chief executive of SEPA, called for a revolution in building standards and micro-renewable sources of energy, such as mini-windmills for houses and the development of "clean-burn" waste incinerators to provide power and heat for local communities.

Dr Gemmell said Scotland was making "a complete mess" of dealing with waste of all kinds and said current building regulations on insulation and energy conservation were equivalent to those used in Sweden in 1923.

He added that evidence for climate change is "overwhelming" and those who deny that it is a problem are like Creationists arguing against Darwin's theory of evolution.

"What we are doing is deeply, deeply unsustainable and it has to change," he said. "For us, that means, as soon as we possibly can, getting our resource use down to a fifth of the current level.

"We have got very dramatic changes to accomplish and we're not doing that well, but there are clear signs of things we could do to make things better. There's absolutely no room for any kind of complacency on this. We have got to do things and do things urgently in Scotland."

Dr Gemmell dismissed those people who deny that global warming is a real problem or claim that it is part of a natural planetary cycle, with man-made factors such as the increase in carbon dioxide playing only a small part. "It's a bit like the Creationist view at the moment trying to challenge Darwin," he said.

"My personal view is there is overwhelming evidence that climate change is a reality. And if we are where we are and it is natural, you don't want to sit around thinking 'We don't want to do anything because it won't make any difference'.

"If it was natural rather than man-made, the desperate need for action would still be there. In a sense, it's an interesting scientific seminar to worry about why it is happening, but we have got real problems now.

"This is about science to some extent but, I suppose, unpopularly, it is also a morality thing.

"We are putting this planet under huge strain ... the planet our children and grandchildren will live in will be dramatically different and I don't mean better."

The dramatic loss of ice from the Arctic and eastern Antarctic, melting glaciers in the Himalayas, Scandinavia and North America, changes to the Gulf Stream and the increasing frequency and intensity of hurricanes were all signs that climate change was happening, Dr Gemmell said. Closer to home, parts of Essex are disappearing at the rate of more than 30ft a year because of rising sea levels.

"If these issues seem to you to be tragic but distant, you are probably making at least one of two of the mistakes common to those of us who enjoy a western lifestyle," Dr Gemmell said.

"The first is thinking that things that happen in other parts of the world don't affect us directly.

"The second mistake is our post-industrial belief that technology has allowed us to 'conquer' nature, that we as a species are detached from it.

"Nothing could be further from the truth. We all have to do something."

And in Scotland people were using about five times the amount of resources they should be, if everyone on the planet was to live sustainably.

"I think we are perhaps not doing all of the things yet that we need to do," Dr Gemmell said.

"That doesn't mean the government isn't trying, [but] there's absolutely no room for any kind of complacency on this.

"We have got to do things and do things urgently in Scotland and we need to be doing them pretty quickly.

"Our houses desperately need to be better insulated, we need the means of using lower-carbon fuels, we need to travel by air less and use more sustainable forms of transport. "We're still making a complete mess of handling not just domestic waste, but commercial and industrial waste."

Dr Richard Dixon, of WWF Scotland, said he broadly agreed with Dr Gemmell, but added that SEPA was "toothless" in many areas relevant to climate change, such as transport and building regulations.

"I'm always pleased to see a government agency saying such strong things about climate change," Dr Dixon said. "SEPA regulates industry and that is important, but they do genuinely find it frustrating that they cannot do more because they do care."

He said the burning of waste was the main difference of opinion between them as Dr Dixon said this might detract from efforts to recycle it.

Duncan McLaren, the chief executive of Friends of the Earth Scotland, pointed out that an estimated 328,000 householders in Scotland were classed as being in fuel poverty because they could not afford to adequately heat their homes.

Greater energy efficiency would therefore not only help the planet, but also the poorest section of society.

"There is really something wrong with the way we are building our homes, the energy just goes out the walls and through the roof spaces," he said.

A Scottish Executive spokeswoman said "good progress" was being made on recycling municipal waste, with some 25 per cent either composted or recycled. The amount of commercial waste going into landfill sites had also fallen from nearly 14 million tonnes in 1997 to eight million in 2003.

And the spokeswoman added: "At the last check, Scotland was fourth in Europe in terms of energy efficiency standards in buildings. We are also committed to developing an energy efficiency strategy for Scotland by 2008.

"And by 2008 we will have funded micro-renewables to the tune of more than GBP 12 million and are fully committed to their development."

Building standards were also being reviewed.