This is the transcript of a video interview produced and directed by Michael O'Callaghan at the U.N. World Summit on Sustainable Development, in Johannesburg, in 2002.
Full transcript (1,697 words, slightly edited for clarity).
© 2002-2019 Global Vision Foundation.
At the time of this interview, Dr. Ernst Ulrich von Weizsäcker was the Director of the Wuppertal Institute for Climate, Environment and Energy (
He was also a member of the German Parliament, and Chairman of the Enquète Commission "Economic Globalisation - Challenge and Responses" (
Prof. Ernst Ulrich von Weizsäcker was Co-President of the Club of Rome between 2012 and 2018. At the beginning of his career, he served as professor and director of several universities and institutes, such as the UN Centre for Science and Technology for Development. In 1991, he became founding President of the Wuppertal Institute, which developed into a leading think tank on energy efficiency, material flows and climate policy. From 1998 to 2005 he was Member of the German Bundestag, chairing the Committees on Globalization and the Environment. He then served as Dean of the graduate School of Environmental Science and Management at the University of California. In 2007, he was appointed Co-Chair (with Ashok Khosla) of UNEP’s International Resource Panel.

Ernst is lead author of three Reports to the Club of Rome: Factor Four (1995), Limits to Privatization (2005),  Factor Five (2009) and Co-author of Come On! (2017)
Now you would not expect in this situation for people to be too much concerned with the environment, because this is a more of a long-term concern, while economic questions are short-term. So what we have also been missing is long-term thinking, which can in the long-term be absolutely disastrous!

How significant is the untapped potential for resource efficiency?

 We realise that people can no longer afford idealistic environmental policy. You have to ask yourself, is there not perhaps an avenue available for something that is good for the environment and good for the economy? I believe the chief answer is eco-efficiency or the systematic, strategic increase of resource productivity. So far, people have been thinking of increasing energy productivity by perhaps a percent, or two, or three in certain operations, and were very proud of it. But this is not enough: if we assume that this world is going to double its expectations for human wealth, welfare, economic output etc - and at the same time, just to stabilise carbon dioxide concentrations we have to go down by at least a factor of two in annual CO2 emissions - we see a factor of four looming large before us which has to be closed again. And the question is now, can we increase energy productivity - or carbon productivity for that matter, or other resource productivities - by something like a factor of four?

Now comes the good news: at the Wuppertal Institute for Climate, Environment and Energy, we have been working on this question. So has my friend Amory Lovins from the United States. And together we have published a book called "Factor Four: Doubling Wealth, Halving Resource Use" and we feature 50 examples of how that can be done. [Factor Four: Doubling Wealth - Halving Resource Use. By Amory Lovins, Hunter Lovins, and Ernst Ulrich Von Weizsäker. Earthscan publications, London, 1997. ISBN 1 85383 407 6.] For instance, air-conditioners that need just 25% of the electricity typically used today, or cars that do 150 miles a gallon (or a litre and a half of petrol per 100km), or buildings with essentially no heating needs any longer, or you can go into food: the transport intensity of manufacturing strawberry yoghurt, to give just one example, can be reduced by a factor of 10 or more without any compromise on quality!

Now, these 50 examples seem to demonstrate that it is possible to increase resource productivity by a huge amount, and that is really a great hope for the world. If certain countries - I suspect it will first be Japan and perhaps certain countries of Western Europe - go ahead with these factor four technologies, you are likely to see other countries that so far are hesitant - including in particular the United States or Canada or Australia - following suit, perhaps with a time lag of 10 or 20 years, but nevertheless, they will see this is the new generation of technologies and the only one compatible with climate protection or anyway environmental protection.

When I read your book Factor Four I thought it was so amazing, I gave copies to all my friends.

It has been translated into 12 languages, including Chinese!

What is your view of the prospect for the transition to the hydrogen economy?

Many progressive people today speak about hydrogen - the hydrogen economy. Hydrogen is a wonderful energy carrier, an intermediate energy carrier. But it's no, not a primary energy source. It has first to be manufactured. But then it's fantastically clean. The exhaust gases are essentially water, water vapour. And this is lovely: it doesn't stink, it doesn't pollute, it's wonderful!

But, the question is of course, where do you get the hydrogen from? If you get it from dirty coal-fired plants, or from nuclear reactors or so, it is not an improvement: it is only a shifting the problem from perhaps the densely populated areas to remote areas in Siberia or Canada, but in the end, regarding the greenhouse effect, there is no gain at all. And for nuclear waste problems and other troubles you face with nuclear energy, the improvement is also very little.

So, let's go for the hydrogen economy but let us be very critical about the source that provides the energy in the first place. It could be offshore wind energy; it could be hydro-power in places where it is ecologically acceptable - that then could be Siberia or Canada; or it could be biomass in certain places, that is also absolutely responsible energy production.

From where you're looking and the people you're talking to, do you feel the petroleum age will end soon and the hydrogen age will begin, and if so, in what kind of time frame?

It's a good question. Some people say we are already entering the hydrogen age, and it may take only another 10 or 15 years to become the dominant feature. I for one am slightly hesitant about this time frame, because hydrogen is going to be very costly for a fairly long period of time. And anyway, energy efficiency is just as clean as hydrogen and is available now. So my guess is that the hydrogen economy may be the dominant feature in 2050.

How much energy which is already available, in Europe for example, gets wasted in the system?

The factor of four I've been referring to is a sign of a huge amount of wasting energy. I think there has been a calculation that only 1 per cent of the petrol - the energy contained in the petrol - is used to move and accelerate the passengers in a car. The 99 percent for heating up the air, heating up the street, for moving metals, for moving all kinds of things; because the car may weigh a ton and a half, but the people is only 70 kilograms. So anyway, it's a great waste of energy and that makes it possible to arrive at something like a factor of four. And in many regards it's even more. If you add also the losses from the natural gas in the pipelines in Russia, and the heat lost by poor insulation,. and the unnecessary transport density in many parts of the economy, you will see that there is a huge savings potential.

OK now on economics and...

You may have noticed that my factor four answer to the globalisation challenge is in a sense too euphemistic, it's incomplete. So perhaps it's better to also say a couple of words about globalisation.


Of course it is good to answer the globalisation challenges with new technologies. But there is another problem involved. This is the problem globalisation poses to democracy. Democracy has been invented and further developed for the nation state. Now with a global economy the capital forces are in a sense stronger than the nation states' democracy. Capital can give homework to democratic states, which is sort of turning reality upside down - the reality of good old democracy, where it's the people that gives the homework to the government, and not some anonymous international capital! The question is of course how can we deal with that? Should we go back into the cosy nation state? And here this road is not available, because we have global transportation, global information and all the rest. My suggestion is to establish and strengthen international democratic forces, from democratic states - who can join hands for instance on climate protection in the Kyoto Protocol etc, that's global governance - and joining hands with the civil society which is also considered part of, or an advocate of public goods, as opposed to private goods of capital accumulation.

What do you think is the most important thing that ordinary citizens in Europe and America need to understand now, in regard to the future?

There is a lovely caricature calculation done by William Rees from Canada and Mathis Wackernagel from Switzerland, the so-called ecological footprint, calculating or estimating the area needed to provide for our lifestyles. And the result is that an average American would need roughly 8 hectares continuously to provide for all his goods and services that he or she is consuming. In Europe it may be 4 hectares. In India it is so far less than one hectare. But, if we all go for the American way of life, we - that is 6.2 billion people on this Earth - are going to need three planets Earth, or four. And they are not available. We can't purchase new planets! So we just have to reduce the nature consumption at least in terms of space, but there are many other things including energy raw materials etc. And this is not something like a posterity plea, it's an invitation to re-direct technological progress from just increasing labour productivity - which is a good thing - to also increasing resource productivity, so that we can do with much smaller footprints at the same effect of welfare.
How do you see the past ten years since the first Earth Summt at Rio de Janeiro in 1992?
Rio de Janeiro has been the culmination of environmental thinking world-wide. It was just after the end of the Cold War: everyone was dreaming of this Peace Dividend now to come by the billions of dollars. But then after Rio de Janeiro, very soon after, we have seen a gliding down, a degradation of environmental consciousness world-wide. And a basic phenomenon to which we can attribute that is globalisation. Globalisation essentially means that now international capital has the capacity to allocate wherever on the globe, disregarding political questions altogether, and triggering an extremely intense competition for lowering costs for the private sector companies. The private sector companies then feel forced to put pressure on the state for reducing taxes on capital, on corporations, on high income, etc. Because they can now blackmail the state. In a globalised economy they say "if you in Belgium or you in New Zealand don't behave as we want, we go to another country!" And that has become so strong, this pressure, that you have seen the taxation for the corporate sector or for capital going down systematically during those last ten years since Rio de Janeiro.