Houses with zero energy and the challenge to plan environmently-friendly cities for the future.

DW: You are a member of the Intergovernmental Panel on Climate Change IPCC - and shared the Nobel Peace Prize in 2007. Now you as a meteorologist - are used to forecasting the future.  So what do you think?  Let's say, 20 years from now, will we still be building houses that use energy?

Ulrich Cubasch: I assume not - at least, not in Europe. There are a lot of designs around which basically increase insulation or use solar panels, so, at the end, in 20 years, it should be possible to build houses with zero energy.

So you think insulating houses could actually keep us from climate change?  Save us from climate change? 

Well, in both directions. It first will save us from emitting more CO2. And the other direction is basically that the houses will not heat up so much in summer, which is very important in southern Europe. 

Now you are not involved in the part where architects actually construct the houses in environmentally friendly ways, but more on the city-planning side, so what is their part in the game? 

Well, in city planning we calculate the flow through towns and cities.  We can calculate where we have hot air accumulating or where we have cold pools, and we can estimate and design streets and houses, so that these bad things are not really there any more. 

And with climate change and rising temperatures, the challenge actually will increase for you, right? 

Well, the challenge will increase, but, of course, we can look in the south.  We know for northern Europe how people design houses in the south - in southern Europe -  and they have already adapted in some form. 

You were also involved in a project in Tehran, in Iran.  Which of your ideas can you actually implement there? 

Well, the idea in Tehran is to build a completely new city outside of Tehran.  And we can look at the whole city to see how to design the streets so that they are ventilated enough so that the warm air doesn't get stuck, also so that the air pollution is reduced.  We can also look at the impact of green areas like parks. 

Actually in former times, the city planners and architects actually knew how to build that way.  How come all these skills got lost? 

Well, it was trial and error, what they did, and now we try to do it on a scientific basis.  And we have the computer more or less to calculate it. 

Maybe it also was because fuel - oil - was very cheap, so you didn't have to take care of the local climate, but you could cool the houses down or heat them up, if you needed to. 

Well, that's one point.  The other point is, particularly in Tehran, it's also an increase of population, so you need to house more people on the same area as before.  So you have to build higher houses and more compact. It certainly has an impact.

And that's why all these buildings around the world actually look alike - these concrete bunkers.... 

Well, they don't have to look alike. That's a matter of the architect, but, of course, they grow higher, as you have to house more people. 

A word on your Nobel Prize: what actually happened to the money? 

Well, I didn't get it, I'm afraid. 

You had to share it with two and a half thousand others. 

No, what has been done is that it has been put in a trust fund, and we use it to support people from the Third World who visit to our conferences or to participate in the IPCC. 

(Interview: Ingolf Baur)