I would think it's not an exaggeration to say initially that the combination of threats which are now being made to the planet earth, which is our home, are without precedent in human history, and they are all caused by us. Those forces are driven by over-exploitation of natural resources, over population of a finite planet, and over-warming of the global atmosphere by greenhouse gases.

Within no more than a decade or two, they will enforce a fundamental change in the world economy and in human societies on a scale which governments and particularly the U.S. have not even begun to come to terms with. Irrespective of who controls Iraq or Saudi Arabia, peak global production of oil will be reached within a decade. We didn't extract any oil until 1869 and in less than 150 years we have exhausted half of the total availability of 2 trillion barrels of oil.

Rapidly escalating demand for that oil from the developing world if they industrialise, from China and from India, will outstrip the supply of oil within 2 or 3 decades. Given the overwhelming dependence of this world on oil this will be a disaster. We use it for industry, for almost all transportation systems, certainly for cars and planes, for agriculture and the world's food, and for military capability. The dislocation which the shortfall in oil supply is going to cause will be without precedent. And it will be in the lifetime of all of you and possibly even of me.

Even more serious than the shortage of oil is the looming shortage of water. Half a billion people now live on this planet in a state of chronic drought. Within two decades that number is expected by the UN to increase fivefold, so a third and a half of our entire world population will live in areas which are water short. This will have implications for population displacement and refugee flows. We're already suffering in this country the political turbulence which is caused by refugees seeking asylum. Just think what will happen in the next two or three decades as a result of people being forced to move in order to have water.

Fish play a fundamental role in the human diet, they provide nearly a fifth of the animal protein for people in developing countries. Nearly 50 % of all fish stocks are fully exploited, 20% are over exploited and only 2% are now recovering. On land, degradation and pollution annually take an increasing toll.

Nearly half a billion people live in countries which no longer have enough croplands on which to feed themselves. More than five million people die in our world each year - including what I think is the worst indictment of all, 2 million children - simply from drinking contaminated water, and the diseases which it generates.

By destroying habitats on an increasing scale, we are bringing about an unparalleled loss of biodiversity. By that I mean animal and plant species, forests, the whole range of living things, on which in the end, as we shall realise to our cost, are the habitats on which the human race ultimately depends.

The whole process is driven by widening and deepening industrialisation, and ever more rapacious technologies of industrial extraction. It is also intensified by accelerating population pressures. Our ancestor, homo sapiens, probably moved out of Africa 150 thousand years ago. It took all of the time from then until 1800 for the population to reach a billion. In the last 75 years, which is a twinkling of an eye in human time let alone geological time, population increased another 4 billion. It is now probably just under 6.5 billion.

In addition globalisation has spread the expectation and demand for higher living standards. People don't just want the living standards of their parents; they want to emulate the West, both in our societal norms and our living standards.

The pressure on the earth's resources is simply unsustainable. The most effective measure of that non-sustainability is called ecological footprint. What it does is to relate the average biologically productive land which is available per person across the world, to the average land area required per person in order to sustain living standards.

At the present time we are overshooting by about 30%. We are using capital stock if you like, using the income when the sources producing that income are insufficient, and that 30% overshoot means that we are depleting the earth's natural capital stock. The best way of illustrating that comes I think from the WWF, in their brilliant report last year (2003) called Living Planet, which says that in 50 years time, if nothing changes, we will be exploiting the resources not of 1 earth, but of 2 earths. And as they wryly noted and some people will have observed, we only have one.

I wanted to show the context because on top of all of this is the steadily worsening phenomenon of climate change threatening to make parts of our planet uninhabitable perhaps within a century or two if the burning of fossil fuels continues. I sound very much like a pessimist, but the definition of a pessimist is someone who has to live with an optimist, and amongst listening to my political colleagues I'm afraid that it's very easy to be a pessimist.

The prospect is exacerbated by new evidence which has recently come to light. Greenhouse gases form a blanket in the lower atmosphere. The suns rays are caught by this blanket and trapped in the atmosphere, and that is gradually increasing the global temperature of the earth.

What is worrying is that the rate at which that is happening has, over the last half century, doubled. According to the latest evidence over the last two or three years the rate of increase of greenhouse gas concentrations has increased from roughly 1.5 parts per million increase per year to 3 parts per million.

The other evidence, which is even more worrying, concerns runaway feedback effects. Under runaway feedback a process can reach a certain level of momentum at which point it unleashes major quantum increases, and the whole process can escalate out of control. The risk as a result of certain clear causes is there for all to see: the die back of the Amazon; the collapse of continental ice sheets – we've already seen ice bergs the size of Wales or Luxembourg breaking off from the Antarctic ice sheet and Greenland; the release of billions of tonnes of methane hydrates which are trapped at the bottom of the ocean; or the loss of ocean sinks.

That's about as bleak as I'm going to be, and I'm now going to try and be a bit more positive. There are those who believe that this is not inevitable, but we do have to fundamentally change if we're going to address climate change.

The Russians have finally brought the Kyoto Protocol into being because they had decided according to their own calculations - nothing to do with the world environment, but all to do with the Russian economic self interest- that they are going to sign up to the treaty. That will take us over the threshold point, which means that it comes into force early next year, and it will become enforceable.

That is probably the most complex and wide-ranging international treaty ever negotiated. I agree it doesn't amount to all that much. The most that can be achieved is to reduce the level of greenhouse gases in the atmosphere for the thirty industrialised countries which are participating by two to three percent by 2010 compared to 1990. Not much. But if the Kyoto protocol had not been signed in 1997 that would not have been a reduction of two to three percent but - other things being equal - an increase of twenty to thirty percent.

It is a significant change of direction, but nowhere near enough. No-one believes the politicians any more, but what the scientists say - and they are united on this virtually across the whole world - is that we need a reduction not of two or three percent but of sixty percent if we are going to arrest the increase in global warming and ultimately to reverse it.

Now that is mind-blowing. Its easy to come up with a figure like that, but actually realising the implications of that for our economy, our society and our lifestyles is absolutely mind blowing. Perhaps the greatest importance of Kyoto is that it has set a successful precedent of how the world can tackle the gravest ecological threat to our survival. It is not hopeless. Kyoto is a very important milestone. What is now needed in my view is a series of further international treaties which are aimed at preserving the biosphere, the world in which we live, our habitat, within the limits of the carrying capacity of the planet. That's the central concept in my view – the carrying capacity of the planet.

The scientists are perfectly capable of telling us roughly where those limits are. However that is not the way in which it is going politically. The dominant real-politik within the world economy which started with the sweep to the right of Reagan and Thatcher in the 1980s, is a powerfully de-regulatory one which is designed to give ever-greater freedom of action to transnational companies. In an open globalised economy we are always hearing about the great merits of globalisation. Well there may be some, but there are some huge drawbacks as well. It is all based on the premise that there are little or no limits to the potential for exploitation of the world's resources.

The necessary global agenda is to recognise those limitations and to act within enforceable international law to keep within those limits. If the new US presidency is unwilling to accept this, and if the rest of the word supinely fails to take the lead, then the earth will exact its own price in securing those limits. The ineluctable and relentless pressures exerted by the earth itself will be painful.

Because I am a pessimist I believe that that is going to happen. If some of you think that this is too fatalistic a view - and I hope you're right - what factors might bring the human race and its governments to their senses before disaster strikes? I'm going to suggest three, which are powerful drivers in the direction I think we all want to go, and then I'm going to close by proposing the three fundamental policies that I think we need to pursue.

What are the pressures which are there and which are operating in a positive direction?

First of all there is the possibility of trade sanctions against climate change offenders. That may sound exceedingly radical but I don't think it is actually all that fanciful. The US itself has said it won't take any action in respect of climate change or indeed in respect of any overarching environmental constraint. Why? Because it would cost the US economy too much. When they talk to you privately they say it's a European plot to do down the US economy. But if you take seriously what they are saying the actual truth is that it would cost on the best estimate between 0.1 and 1 % of the level of increase of growth between 1990 and 2010. In other words it could easily be afforded. There is no question about that, so lets take it at face value.

What they are doing is free-riding, which of course gives a subsidy to US producers, and this is why it appeals to them. But the WTO forbids subsidies, and countries which are discriminated against by competitors who use subsidies are permitted under the law to retaliate. I think that if the US remains intransigent the EU ought seriously to look carefully at the possibility of taking a case to the WTO disputes panel. That is one potential driver.

The second driver- and this is a more positive and less confrontational option – is that Kyoto and other multilateral environmental agreements will incentivise the drive towards a cleaner greener world economy. There are quite a lot of opportunities within Kyoto which are designed specifically to provide strong incentives, particularly to developing countries, to pursue a different path to industrialisation.

The route which was chosen, which I think was a very clever one, is called the Clean Development Mechanism. What this does is to say that the developed countries have an opportunity to invest in green machinery, equipment, and green processes in China and India and Africa. Then they can get carbon credits which will enable them to meet their requirements under the Kyoto Protocol. So developing countries get the investment, the developed countries companies get the profits from the investments, and the developed countries get the carbon credits to meet their Kyoto requirements. A win - win - win situation.

The significance and the beauty of this is of course that that is confined to countries which are participants in the Kyoto Protoco. As the market opens up from the beginning of next year I certainly believe that US industry, which isn't particularly ideological but is profit driven, will feel excluded from this enormous new thrust which is going to dominate economic activity in the 21st century. Whatever they say, people in industry and very high positions will be beating a path to Bush's door and saying 'we're going to have to think again on this'.

The third driver is the risk to the world capitalist system which I think may concentrate minds much more closely. The number of major natural catastrophes per year has tripled since the 1960s, and the global economic losses from these events have risen 10 fold. World GDP is rising at about 3% per year but the global re-insurance costs of protecting against these natural catastrophes has been rising at about 10-12% over the last 10 years. You don't have to be a mathematician to realise that at this rate somewhere around 2065 it will cost roughly the whole of world GDP to provide the re-insurance. What it means is that far before that there is going to have to be a complete rethink, because people will be exposed to increasing incidents and ferocity of natural catastrophes against which they cannot secure insurance.

Now I wish to talk about the three policies which I think we should be adopting. I've already mentioned the drivers which I think are edging it in our direction, but we still have to have a clear policy or programme if we're going to save the world from the worst kind of excesses I've been talking about. The first is to try and find a way of restricting the use of fossil fuels. The second is to find alternative sources of power. The third is to find ways to use the energy which those fuels supply a lot more efficiently.

So how do we reduce the use of fossil fuels? Such is the power of oil and coal and gas that even on the most optimistic estimate it will be at least half a century or even a full century before they are phased out. If it could be shorter it would be much better because action needs to be taken, and as soon as possible.

Kyoto was about rich countries - they were forced into the agreement because it's a global problem and requires a global solution. The developing countries said to the rich countries: "Don't come to us! Don't expect us to do anything about it. You caused it. You've got the standard of living out of it. You've got the prosperity, the wealth, and now we're the poor ones and we've got to take action. Until you take action, we're not going to come in on this enterprise even though we are the main victims." With Kyoto coming into place there is a very real possibility that China, India, Africa, Latin America, Asia will begin now to look to join within a reasonable period of time.

After all, it is in their long term interests to do so. The problem is that they want to industrialise.

There is no way that you can stop India, China and South Africa, Brazil, Indonesia, from expanding, unless America decides to invade every country in the world it doesn't like. We can try and make it down the greener route, but expand they will. They are going to increase carbon emissions and fossil fuels will still be in very high demand for a while to come yet.

There is a level of greenhouse gas concentrations in the atmosphere which we shouldn't go above. In the mid eighteenth century, before the industrial revolution, that level was 280 ppm. It is now 380 ppm. There's no certainly about this, but scientist's marker in the sand beyond which we shouldn't go is double the level before the industrial revolution – say 550 ppm. We are already headed inexorably very close to that limit. There's a very long lag time and even if we made all the changes I'm talking about little would change for about the next 100 to 200 years because of the time it would take to dissipate the level of those gases in the atmosphere.

So, if we're going to keep below 550 ppm how are we going to do it? What's the game plan to try and ensure that the world - the global commons - doesn't get above this level whilst at the same time getting the consent of the developing countries as well as the rich countries to keep within the level? The only way you can do that is a programme which has been called Contraction and Convergence.

What this means is that the rich countries are going to have to contract, that's where we come into this minus 60%. The poor countries are certainly going to have to reduce carbon emissions as best as they can, but given the rate of industrialisation, there needs to be some headroom and leeway to allow them to achieve that whilst still playing their part within the whole world to keep below this level of 550ppm.

Now is that going to be agreed by everyone? Unfortunately, I would say that the chances of achieving that at the moment with the current American presidency is about zero. We've just had wars in Afghanistan and Iraq, both of which, in my view, are primarily about oil. As big oil comes to an end in our world America is trying to gain control of the major repositories which are left: the middle east, the Caspian - hence Afghanistan - and of course West Africa. The US has never shown much interest in Africa but now that 60-70 billion barrels of oil have now been discovered off West Africa and there are huge American interests in that area.

You can understand US resistance to Kyoto. US investment in hydrocarbons continues to rise, with US coal consumption expected to increase by a further 25% in the next 20 years. Nearly half of the power in America, the biggest economy in the world, will come from the coal fired sector. Just think of the jobs and votes which are involved in that in the Appalachians, the eastern sides of the states as we've seen again in the last elections. You can't go to the Americans and say 'hey lads what we've got to do is keep below 550, so we've got to contract and you're going to have to contract the most in order to allow the developing countries the opportunities to develop'. What sort of reply do you think you're going to get to that? So that's the problem- and it's a huge, huge political problem. There is no other way of doing it, but the political channels at the moment and the most important country is currently blocked.

The next question is what do you do if you rule out oil and coal and gas? Of course renewable sources of energy are an answer to that– wind power, biomass, solar power, tidal power, wave power etc. The eclipse of oil, which is inevitable, the gradual run down of coal, and the phase out of nuclear power were all heralded in the governments energy white paper of last year. They need to be followed through as the highest priority with a major and massive drive towards renewable sources of energy. Has this happened? Absolutely not.

At the moment solar energy and wind power have enormous potential. There is enough power in solar energy striking the earth to power the world economy forever. We utilise much less than 1% of it. But it is costly, the technology isn't there, and it is going to take some time down the track before we get there. At present solar power and wind energy provide less than half of one percent of world energy.

They still have enormous hurdles to overcome. The best solar PV cells still have the efficiency of less than 10%. The cost of manufacturing the silicon based solar PV cell remains prohibitively high, and the energy generated is intermittent. In the UK, where we like to see ourselves as a climate change leader, the switch to wind power is miniscule. Even the latest licensing round means that we will install enough capacity for about 5% of electricity demand. Pretty pathetic.

Anyone who has spent time like I have at the Labour party conference at Blackpool pier knows that we have one of the greatest capacities for tapping wind almost anywhere. Despite that, far too little is being done. There are obvious barriers that we are not really meeting: planning blockages, aviation issues, the fact that the MOD seems to think that aviation will collapse if we put wind turbines out in the channel or the north sea, grid network constraints both in distribution and transmission, and financing.

However, I give you one extremely important bit of research from the university of California. One mustn't forget that the American people are very different by and large from the American president. There are an awful lot of Americans who are just as committed as we are to doing something about this.

They did a bit of research which very revealingly measured the 'well to wheels' pollution accounted for by each gallon of petrol. From when the oil is extracted and refined to when it is burnt in the engine, the costs include the air pollution, the climate change effects, and - as the Americans are finding out to their cost in Iraq- the military expenditures to protect the oil supplies. Now if all those social, political, military and environmental externalities are all taken into account then the hydrogen fuel celled car, which is now priced far beyond commercial viability, actually dramatically becomes 25% cheaper than a petroleum driven car.

I think that's a staggering fact, and the politicians should leap on that. If they had the courage to encapsulate environmental costs fully into the political system then we could have a quite different kind of economy. But for the moment renewables are set to make only a very tiny contribution, and it requires a massive change in both transport and domestic sectors.

This is my third point. Is there any way in which we can use the energy more efficiently? The volume of energy which we squander is absolutely prodigious. Just let me give a few statements, which stagger me and I think they might you.

US power plants discard more energy in waste heat than is needed to run the entire Japanese economy.

Only 15% of the energy in a gallon of petrol ever reaches the wheels of the car.

Less than a quarter of the energy used in a standard oven reaches the food.

It had been calculated that a mere 2.75 mpg improvement in the fuel economy of American cars and light vehicles would be enough to forgo oil imports from the gulf entirely – a rather better solution one would have thought than launching a war in Iraq.

Energy efficiency gains could save more oil than could be found in the ground, and at a lower cost than the average market price for oil. The implications for this are absolutely stunning.

If we reduce energy intensity by just 3% a year, every year, then we could meet world demand by 2100 with only a quarter of the energy that we use today.

But as always there is a catch. The trouble is that the efficiency dividend which I've just spelt out, which is absolutely massive, it has been misspent. The fuel economy of cars has increased dramatically over the last decade, but how have consumers responded? By buying more and bigger cars. In terms of energy efficiency Sports Utility Vehicles are a disaster.

Today's lighting systems are dramatically more efficient but any potential energy savings are swallowed up by dozens more recessed or tracked lights. Other energy savings are spent on more air conditioning systems. Don't forget that half a century ago we didn't have air conditioning at all and now its virtually de riguer in parts of the US and increasingly so in parts of Europe. There are big screen home entertainment tv centres and additional refrigerators in the garage or the shed down the garden as well as two in the house.

It is extraordinary, and the lesson in all of this is very clear –the perversity of minimising cost which is the goal of technology, rather than maximising conservation, which is the goal of environment and sustainability. What this opens up is a real prospect of a very different energy future – not one that is based on carbon free energy sources alone, which as I said earlier is coming on stream very slowly, but based on energy saving technologies too. We cannot win against climate change unless we shift away from fossil fuels to carbon free renewable sources of energy, but we need the gains in efficiency to power cars, houses and industry with only a half or a quarter of the amount of energy.

So I conclude, climate change is the biggest challenge mankind has ever faced. No one policy is sufficient to confront it. It requires the combination of contraction and convergence to force down equitably but effectively the havoc caused by fossil fuels; a massive switch egged by government policies and fiscal incentives into renewable sources of energy; and a huge campaign to maximise conservation and relentlessly squeeze the colossal waste of energy which is endemic in today's society. The political question as always remains at the end – are we yet ready to do it?

Michael Meacher is a Labour Party member of parliament. He was UK Minister for the Environment between 1997-2003.

Climate Outreach Information Network is a charitable trust specialising in public education on climate change and its impacts. COIN works with individuals, households, small community organisations and progressive businesses to directly engage the public about climate change, and supply the means by which they can reduce their own emissions.

This paper was transcribed by Jo Hamilton and edited by George Marshall. It can be distributed and reproduced freely and without permission for non-profit purposes.