Question: What could a climate scientist bring to the debate among physicists over the interaction of cosmic rays with the Earth’s atmosphere?
Answer: the coffee.
Physicists have long maintained that the question of climate change was properly within the realm of physics rather than that of those glorified weathermen who call themselves “climatologists.” Last week we got confirmation of that. It came in the form of a study by physicists in Switzerland.
The study, which was published in the prestigious peer-reviewed science publication Nature, gave support to an alternative theory of climate change first proposed in the late 1990s by a Danish physicist named Henrik Svensmark.
Svensmark proposed that the wild swings in climate over the eons could not be attributed to a cause as minor as slight increases in gases such as carbon dioxide. Instead, he theorized, those swings could be caused by solar activity. Cosmic rays from the sun might play a key role in cloud formation in the Earth’s atmosphere. Clouds can trap heat.
That was the theory. But like all theories, it had to be tested in the lab. The lab in question was the CERN particle accelerator in Geneva. And sure enough, the study showed that ionization increases the nucleation rate of condensation nuclei.
In other words, cosmic rays can have an effect on climate. Meanwhile, atmospheric gases don’t seem to play that big a role in cloud formation, the study concluded.
Physicists have suspected this is the case ever since Svensmark advanced the theory. One such physicist with whom I’ve discussed it at length is William Happer, who runs a physics lab that is named after him at Princeton University. The primary source of confusion for the layman, said Happer, is the supposed consensus among scientists that greenhouse gases such as carbon dioxide raise the temperature of the planet.
There is indeed such a consensus, he said, but it goes only as far as the effect of the CO2 itself. And the recent rise in CO2 could account for an increase of, at most, a 10th of degree, he believes.
To get to the massive temperature spikes predicted by Al Gore et al., you need what’s known as “forcing.” That’s the theory that a relatively small increase in man-made greenhouse gases, such as CO2, will have a large effect on water vapor, which is by far the most prevalent greenhouse gas.
When I e-mailed Happer asking if we could chat about this, he informed me he was about to take a trip on the Trans-Siberian Railway and would be out of touch for a week. That’s why physicists are fun to talk to, by the way. They do lots of cool stuff. If you doubt that, read “Surely You’re Joking, Mr. Feynmann,” in which the late Richard Feynmann describes applying his talents to safe-cracking and gambling.
Anyway, I called another scientist skeptical of the climatology crowd, Don Easterbrook. Easterbrook is a professor of geology at Western Washington University who is an expert on the Pacific Decadal Oscillation, a wind-flow system over the Pacific Ocean that has a huge influence on the Earth’s climate.
It’s back to the drawing board for the climatologists, he told me. Their models need to change to incorporate the new data.
“They couldn’t even predict 10 years ahead,” said Easterbrook. “The bottom line is their modeling results have been a dismal failure.”
The reason is not far to seek, he said. When it comes to the sun, those models took into account only the amount of heat being directed toward the Earth. They didn’t take into account the effect solar activity has on cloud formation. That’s where the physics comes in.
“Unfortunately, you do have to be a rocket scientist to understand this,” said Easterbrook. “But those climate scientists are virtually all computer modelers.”
They’ve now got something new to put into their models, he said. The CERN study doesn’t necessarily show, as some have claimed, that we’ll soon be entering an ice age or that greenhouse gases have no influence whatsoever. But it does show that computer models are only as good as the data they’re based on.
And when it comes to what could be the key piece of data needed to model the climate, the climatologists are now at the mercy of the physicists. That area of research is far above the climatologists’ heads — literally and figuratively.
ALSO: Who's in denial now? In this piece, Svensmark makes a compelling argument that climate scientists need to rework their models to include the effect of solar activity:
Ever since we put forward our theory in 1996, it has been subjected to very sharp criticism, which is normal in science.
First it was said that a link between clouds and solar activity could not be correct, because no physical mechanism was known. But in 2006, after many years of work, we completed experiments at DTU Space that demonstrated the existence of a physical mechanism. The cosmic rays help to form aerosols, which are the seeds for cloud formation.
Then came the criticism that the mechanism we found in the laboratory could not work in the real atmosphere, and therefore had no practical significance. We have just rejected that criticism emphatically.
It turns out that the Sun itself performs what might be called natural experiments. Giant solar eruptions can cause the cosmic ray intensity on earth to dive suddenly over a few days. In the days following an eruption, cloud cover can fall by about 4 per cent. And the amount of liquid water in cloud droplets is reduced by almost 7 per cent. Here is a very large effect – indeed so great that in popular terms the Earth’s clouds originate in space.