So in my lifetime the population of the planet has grown by factor 3, from 2 billion to 6.6 billion.
And in the same period the global energy used and greenhouse gas production have increased by a factor of about 8.
And the greenhouse gas in the atmosphere, the CO2 in the atmosphere has risen from 280 parts per million to 380 parts per million.
This is a very substantial amount over a short period of time,
in the inset it’s over a period of time of a couple of hundred years
and in the bigger picture it’s in a period of time of a thousand years.
To compare it with ice age timing which we see also a little bit, which are much, much slower.
So this is very, very different.
The temperature has risen by about point 8 degrees since the beginning of the industrial age
and the sea level has risen 20 centimetres.
These are measured quantities which some people question but I think are, it’s nearly impossible to question these.
And here this gives a picture of the, these things I have from the most consequent organisation studying these questions
which is the international panel on climate change.
This is the growth of energy over the last 50 years in different regions of our globe.
The first one is the United States of course, Europe is here, let me focus also on China which is there
and you can see that in the United States and in Europe the growth has been about 1% per year
and in China right now the growth is 3.6% per year.
And notice that China has overtaken in the total energy use, the United States.
And of course for me as best I know energy use and CO2 production and oil consumption, fossil fuel consumption are the same thing.
So this is to give you a little notion of the energy use by sector.
The electricity is about 40%, transport is about 20%, the industrial consumption is about 20% and building heating is about 20%.
And the present energy sources are fossil fuels 80%,
so fossil fuels are essentially all the energy on which our economy and our life depends.
And renewable combustible fuels are 11%, hydro power is 2.3% and nuclear is 7%.
This is the rest of the 20%.
So how long will this fossil fuel last?
One problem is that these fossil fuels will not last; another problem is that they contaminate our atmosphere.
Of course how long they last depends on how much there is and how fast we use them
and on this scenario which I’m using here to see how long they will last, I assume that the resources,
the ones which are known, of course there are others which are not known but I don’t know what they are.
So if I take the known oil, natural gas and coal resources
and I assume that the present population will grow 1% a year which is what it’s doing now.
And that the per capita energy use will grow by 2.5 % per year, which is what it is now on the average.
Then the oil will be gone in 25 years and after that time if you use natural gas for whatever we used oil,
in addition to what we use it now, it will last 10 years more.
So both oil and natural gas will be gone in 35 years.
And if after that we learn how to make fuel for transportation out of coal, which is,
Hitler knew how to do so I suppose we can also learn how to do it again, then the resources will be gone altogether in 60 years.
So it’s a very finite amount of time and your children and grandchildren will,
may be there and of course it will not happen like this because before all this is gone there will be some social changes.
And I hope they’ll be very much sooner.
The atmospheric CO2 level will be 700 parts per million, so almost 3 times what it was before all this happened.
And the temperature rise will be about 6 degrees centigrade and the sea level rise will be several metres.
And these changes will of course cause large problems in the societies
and there will be conflicts which will be as a result of that but I cannot comment on those things.
This is just a graph which I took from Llewellyn Smith who gave us a seminar on this
which gives an illustration of how fast all these things are happening,
this is the use of fossil fuel over time and the time scale is 10,000 years.
So this is since the time which we started learning how to write,
nothing happened and then all of a sudden we use all the fossil fuels but they’ll be gone in a very short time.
But humanity hopefully will survive a little bit longer.
Now what can be done to try to avoid this catastrophe?
And one important thing to remember is that all these responses take substantial amount of time
and the time scale which is there is only a few decades and any kind of response is also a few decades.
So it’s certainly very interesting to respond as quickly as possible
and over a shorter time as possible to try to mitigate the problem.
Of course one thing is to reduce the population, I think this would be a very important and good thing.
One would be of course a way to do this which would be effective would be a nuclear war,
it would also have the benefit of putting dust into the atmosphere which reduces the temperature.
And another important thing is to reduce consumption,
the trouble is that reduction of consumption of energy is very much in conflict with our expanding
and competitive economy which requires right now for success an ever increasing production.
So how to reduce consumption, I think we could live in a way which is not so much worse, consuming less.
But our economy, how to accommodate this is not obvious.
Another thing of course is increase the energy efficiency in buildings or in transportation and other things.
This is just to illustrate the, this is a graph which is produced by the Human, by the United Nations Human Development,
this is called the Human Development Index by some United Nations organisations.
And it shows the energy used per capita, this was done in about the year 2000, energy used per capita in different countries.
And the energy, the Human Development Index is based on education level, on health level,
health, medical treatment level as they evaluated.
And the GDP, the production index per capita.
And you can see that you can achieve, according to them, an index, China has an index of .75
and uses 1.8 kilowatt hours per person and the US has an index of .93 and uses 12,000 kilowatt hours per person.
The human development index people think .8 should be adequate for people to get along on.
That may be 2,000 kilowatt hours per person is quite easily achievable.
Now how can you avoid using fossil fuels to produce energy?
And let me focus on electricity, solar energy is clearly there is plenty of it,
and I will then focus when I'm through with this on thermal solar power and what is being done to develop this technology.
This in my opinion is an absolutely clear way to go and I think we should do more to develop it.
Then there is nuclear power which you could use much more, it’s now at 20% or less than 20% of the electric power which is used.
There is big public opposition to it, it’s cheap and its pretty much ok in my opinion, but there are certain questions
which is the question of how to deal with the waste for long term storage and possible accidents
and the vulnerability to terror attacks.
And the fact that nuclear energy plants, energy technology is also useful for making nuclear weapon technology.
So the things are related.
So there are some hesitation about using nuclear energy.
But I think it’s much better than using fossil fuels.
There are hydro electric energies, of course an extremely fine way of making electric power.
But I think the extension of the present use of hydro electric power is not very easy.
There is wind energy and it’s being developed in many places now with good intensity,
I think it has a very serious problem with it, namely the wind power is very unsteady with time.
And storing electric energy which is produced by wind power is a technological challenge which I don’t know how to meet.
So I don’t think wind power is as good a possibility by far as solar power in the deserts.
There is geothermal which is not accessible everywhere, it’s now a very small amount
and I don’t know how big its possibilities are but I think they’re limited.
And there’s another thing which I want to say just a sentence about which is carbon sequestration and storage,
the notion has been put forward that you, this doesn’t avoid the use of fossil fuels but if you use fossil fuels
then you capture the CO2 which is produced and you put it under pressure into the ground,
somewhere deep into the ocean or into some hole in the ground.
And it would, as best I can tell, increase the price of electricity production by about a factor 2.
It’s not impossible to imagine that it could be done on a large scale but the technology has not been explored,
almost nothing is known about the reliability of storing CO2 under high pressure deep in the ground or deep in the sea.
And so before anybody can really propose this, development work has to be done in order to check this.
And of course it has the disadvantage for me that it doesn’t save the use of fossil fuels.
It would be nice if a future generation could still have some fossil fuels which it could use.
And so we’re worried about the problem of trying to do something and one thing
which one has to keep in mind is that whatever solution you propose
has to be equitable in the relationship between the effect on developing countries,
compared to those which are already developed so this must always be taken into account.
And well the problem of reducing the use is I’ve already commented on, it conflicts with our market economy.
One absolutely, I mean to illustrate this a little bit also,
one very clear way to try to reduce the use is to make a CO2 tax, a tax for carbon consumption,
everybody who uses it has to pay that tax.
It would encourage you to finding other ways and would discourage the use of carbon.
But our economy being what it is and our governments having to worry about that,
it has not been adopted by any country, it would have to be adopted in a global way.
And clearly from a political point of view the biggest problem is that if you do it in your own country
you have to pay a certain price but your benefit is not in your own country,
it’s globally and unless the rest of the world does the same thing or does it comparably you won’t benefit from it.
So it requires a global collaboration, global political cooperation which we certainly have never achieved,
it would be a fantastic achievement, but I am very pessimistic about it.
Ok now I will finish what I can tell you about by giving you a little bit of an idea
of what is happening to exploit the possibility of getting thermal solar energy from deserts.
And my pictures I take it just for Europe but for the rest of the world similar.
That essentially the bulk of electricity for Europe would be produced by captors of solar energy in the desert region,
it would require about, a few percent of the deserts of the world to supply all the electric power of the world.
The captor would convert the solar energy into heat of some liquid,
some thermal vector liquid which now they use some oil which can go to temperature of about 350 degrees centigrade.
And that you could, then one big advantage of this technology
is that the heat which you produce is really relatively easy to store in masses of material
which have enough thermal capacity, the material which is used now in present development projects is a gas,
a salt mixture of sodium nitrate and potassium nitrate which can go to temperatures of the order of,
I think something like 500 degrees.
And you can keep this, of course you are limited in the volume, it costs you money to make the volume of this storage systems.
But you can quite easily do it at prices which are not too much, so that you can store overnight.
And so you can make electricity for day and night in the desert, which is with a fairly good efficiency over the whole year.
And then you require a normal steam turbine, whatever heat vector you have produced has to drive a normal steam power turbine.
And then what you also need is something which doesn’t exist, is the network of transmission lines,
electric transmission over distances which are much larger than those which are presently used,
presently they may be hundreds of kilometres but you need now thousands of kilometres.
And AC doesn’t work but DC works and you can do it at a price which is acceptable but it’s something you have to worry about.
And the technology is known.
So I show you some pictures of some developments in the United States,
federally nothing is going on but California with Schwarzenegger
has a very strong program of having solar concentrators in the Mojave desert
and there are also projects in Nevada, in Spain and this has been going on since the early 1980’s,
in Spain there are now some projects, one of them is just coming in to operation in southern Spain.
And there they are focusing very much also on storage, over night storage which is not yet happening very much in America.
And there are 2 projects which, or 3 projects in Spain which I’ll call attention to.
Then there’s a project in Italy where a different thermal vector is proposed.
And then there are 2 new projects or 3 new projects in America, in California which I just heard about in the last weeks,
and which I find quite interesting.
So this is in the Mojave desert and the concentrating devices are hyperbolic or parabolic mirrors
which you see there in long rows and they focus the light, they are about 5 metres across
and they focus a light on a tube which is about 8 centimetres in diameter, which contains oil,
which can go up to a temperature of about 350 degrees centigrade, Carlo you can correct me, you know better.
And there are now of the order of 400 or 500 megawatts of these systems in place.
And they’ve been functioning for 20 years and it’s not trivial to keep them in operation
and there are problems, but they’ve been managing to keep them with a substantial efficiency.
So it’s some demonstration that the technique can work.
I should, for those who are not familiar, the 450 megawatts
which they can produce corresponds to about 1 normal coal or gas electric plant except that this one doesn’t work at night.
Here is a project in Spain, it's called Andasol, which has been now in construction for a few years,
just this month it's supposed to come into operation, I don’t know whether its really come into operation yet or not
but it uses also storage, it uses the same parabolic troughs and the same liquid.
Here this shows you the location in southern Spain and this shows you one of these tanks,
one of these tanks is if I remember now right, is 35 metres in diameter and 13 metres high and contains the salt.
And they have 2 of these tanks for the storage.
This is, show another kind of method which is, has very great advantages
and has also some disadvantages is solar tower where you reflect the solar light.
You focus the solar light from a field of reflectors on the ground on to a cylinder on top of a tower
which contains the thermal vector fluid.
And this is a plant in southern Spain which is under construction, which is going to make 17 megawatts,
it will have storage, bigger storage than the Andasol plants.
And it uses the same salt for the thermal vector.
This is clearly an interesting technology.
Here is some proposed project in Italy, in Sicily, which is proposing to,
which is exploring the possibility of using together with these parabolic reflectors,
using molten salt, it’s technically a challenge to use this molten salt, this project has been going for a while.
And some troughs have been tested but the whole project doesn’t exist yet.
And so to end with a few words about new larger projects in California.
For me the interesting thing was that they use different technologies,
so it’s not so easy to convince yourself just what the best technology is and we should really pursue more,
much stronger development effort in exploring these technologies.
The 3 new projects, I’ve listed 2, since then I found out about a third and so let me talk about these 2.
There’s a solar tower project which, but now uses water for the thermal fluid at a very high pressure
and a very substantial temperature.
A temperature over 300 degrees centigrade and a pressure of the order of, if I remember, 200 bars or 280 bars.
And there’s a comparable project and these are now, they have just been approved by the,
or accepted by the power companies in California, uses a different kind of mirror than the parabolic trough.
A mirror which is called Fresnel, I won’t describe it, doesn’t matter, it's very simple physics and optics,
it has some advantages and to me it makes sense.
But I’m not competent to really make a judgement.
Which they think they can make more cheap than the current parabolic ones.
So let me stop with that, let me just say renewable energy at acceptable cost.
By the way, I should have said that for the Spanish plants the government has agreed to give the companies
which are building these, a price for electricity which they deliver, which is 3 times the present price in Spain.
But the American new projects, they are being offered a price for their electricity
which is less than double the present price, so they think they can make it cheaper.
And I think there’s good reason to believe that you can make solar thermal electricity
at a price which is absolutely comparable to what you can expect in the next 10 years for fossil fuel electric power.
So the technology I think is available now.
The thing which is the challenge is to find some global political will and collaboration which can realise such a thing.
Thank you very much.
(applause).