But if humans, through carbon dioxide emissions, are affecting climate less than we think, would that mean we may have more time to reduce the harmful effects?
Yes, that could of course be a consequence. But I don’t know how to get to such a conclusion because right now everything is set up that CO2 is a major disaster in society.
Do you agree that carbon dioxide is having at least some impact on Earth’s current warming?
Yes, but you have to give the sun a role. If you include the sun in the right way, the effect of CO2 must be smaller. The question is, how much smaller? All we know about the effect of CO2 is really based on climate models that predict how climate should be in 50 to 100 years, and these climate models cannot actually model clouds at all, so they are really poor. When you look at them, the models are off by many hundreds percent. It’s a well-known fact that clouds are the major uncertainty in any climate model. So the tools that we are using to make these predictions are not actually very good.
What do you hope to do next in pursuit of your theory?
I’m extremely excited about our next experiment, which will happen in the next couple months. We are planning to go one kilometer below Earth’s surface because when we do an experiment in the basement we cannot get rid of the radiation. Cosmic rays are so penetrating that there’s always ionization in our chamber and we cannot get to zero ionization. I think it will be the first time that people are attempting an experiment where there is no ionization present. I think it will be quite fascinating because it will tell us something about the details in the mechanism.
Do you think then that individuals and societies as a whole need to try to conserve energy? Do you use compact fluorescent lightbulbs, for instance?
Yes, yes, we use those. And I ride a bicycle. There are good reasons to conserve our resources and find a more economical way of using energy, but the argumentation is not linked necessarily to climate.
At this stage in your work, how confident are you that your basic theories are correct?
I think it is almost certain that cosmic rays are responsible for changes in climate. I think now I have very good evidence, and I think I’ve come up with some very good evidence that it is clouds. Of course, we cannot discuss the exact mechanism, but I think we have some very important fragments of these ideas. One extrapolation we could make, for instance: Would this mechanism work in an ancient atmosphere? Would these processes still happen? That is something I don’t know.
You discuss your work as part of an emerging field that you call “cosmoclimatology.” What is that?
It is the idea that processes in space and what is happening here on Earth are connected. It is this idea that when Earth is in a certain spiral arm of the Milky Way, you can associate that with a certain geological period. Previously, the idea was of Earth as a sort of isolated system on which processes evolved. Now all of a sudden it seems as if our position in the galaxy is important for what has happened and is happening here on Earth. It is this connection between Earth and space that’s exciting and why I have given it this name. Most of this research has taken place just within the last 10 years, and it is truly multidisciplinary, ranging from solar physics and atmospheric chemistry to geology and meteorology—even high-particle physicists are involved. The people who are doing space-related observations are very happy that there could be a connection from space to Earth because it makes a good argumentation for understanding processes out there.
These connections, which combine such a variety of disciplines and create opportunities for many lines of work, are surprising and wonderful. It has been a real challenge for me, though, because I have to look at so many different fields in order to work.
You’ve faced more than a few hard knocks in pursuing your scientific career. What keeps you going?
From the beginning, I have found this to be a really interesting problem, and now, I think, it is the potential of it that draws me on. It is something which started as a simple idea and seems to be continually extending, or expanding. That has really been the most important thing. I mean, for instance, I would never have thought that we would find these correlations between the cosmic rays and the evolution of the Milky Way and life on Earth. I never expected that all of these things are connected in a beautiful way.
