The reluctant Laureate – University of Copenhagen

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25 November 2015

The reluctant Laureate

Nobel Prize

In 2007 the Nobel Peace Prize was awarded to the intergovernmental Panel on Climate Change: A body consisting of some 2.500 scientists from all over the world. One of those, an expert on atmospheric chemistry from Copenhagen, had already spent a good deal of his career trying to mitigate climate change using his skill as a chemist. And along the way he had practically helped save the planet.

By Jes Andersen

Wrong Nobel Prize still triggered Champagne

It really was the wrong Nobel Prize, but the students couldn’t help themselves. They were getting exited. Some even started giggling outside the professor’s door. Ole John Nielsen is a Professor of environmental chemistry at the University of Copenhagen. He had spent three decades studying the degradation of chemical compounds in the atmosphere of Earth, and in recent years he had put all that knowledge to use vetting papers on atmospheric chemistry for the Intergovernmental Panel on Climate Change IPCC: Now he was to become a laureate. Not in Stockholm, but in Oslo. Not for chemistry, but for peace. But the students didn’t care. It was a Nobel Prize.

The chemist who saved the world

A Professor at the University of Copenhagen, Nielsen himself is not the kind to exaggerate the importance of prizes and honours, but when students burst into his office on the top floor of the chemistry building in central Copenhagen he slowly got into the spirit of it.

"The students wanted us to have champagne. And as you discover how much that Nobel Prize means to other people, it takes on added significance!

Ole John Nielsen


Department of Chemistry

University of Copenhagen

“Right at first I felt it was silly to make so much of it. But the students wanted us to have champagne. And as you discover how much that Nobel Prize means to other people, it takes on added significance for yourself as well” explains Professor Nielsen. But even though his pride at the prize was rising, it still didn’t measure up to his proudest moment. Back when he helped save planet Earth.

Scientific paper predicted the end of the world

A seminal scientific paper was published when Ole John Nielsen had just started studying chemistry and physics at the University of Copenhagen in 1974: The theory that stratospheric ozone would be severely damaged by man made gasses used to propel paint from spray cans. By CFC gasses like Freon.

“They were saying that this stuff would eat away the ozone protecting the planet from ultraviolet radiation. The increase in radiation would cause cancers and… Well they were practically predicting the end of the world. And being a young and naïve student of chemistry, I just felt I had to take an interest in these compounds, and how they affected the atmosphere” relates Nielsen.

He wasn’t to know at the time. But he would come to play a pivotal role in preventing the disasters predicted in their Nature- article by Mario Molina and F. Sherwood Roland.

Prepared to battle ozone eaters

The idea that any kind of human activity could harm the Earth atmosphere may have been novel in 1974. But by the middle eighties it was becoming blindingly obvious that Freon was eating a hole in the stratospheric ozone layer above Antarctica. By this time Nielsen had been building a reputation of his own within atmospheric chemistry. With the research group he had created he was getting ready to tackle Freon.

Hundreds of thousands of tons released to atmosphere

Freon 12 is a DuPont brand name for Dichlorodifluoromethane: Besides building pressure in spray cans it was also used as a refrigerant in air-conditioning units in automobiles. Over the years hundreds of thousands of tons was released into the atmosphere.

“Back then you just didn’t think about what might happen with these compounds. You’d just use tons and tons of something where you had no idea what the effect might be”, remembers Ole John Nielsen. But the United Nations were thinking hard about CFC’s. In fact they were getting ready to put a cork in every nozzle emitting the stuff.

The obvious choice to investigate replacement compounds

The Montreal Protocol on Substances That Deplete the Ozone Layer was opened for signatures on September 16th 1987. What this international treaty said in essence, was that all compounds likely to eat up the ozone layer were becoming illegal. Freon was going down.

By this time Ole John Nielsen had a considerable experimental acumen in figuring out the atmospheric fates of different chemicals. In one year he and his group published 25 articles on the subject. So when he was approached by chemical producers DuPont with a compound they imagined might replace Freon 12, he wasn’t all that surprised.

“We were the right people at the right time with the right competencies to test this new compound HFC 134a” opines Nielsen.

Thought his mission was at an end

As it turned out the new compound really was less likely to eat ozone. Much less likely. Tests made by Nielsen and his group showed that the new compound had an ozone depletion potential of absolutely nothing at all. A big round zero.

In 1994 HFC 134a replaced Freon in almost all applications. And for a while Professor Nielsen thought that he might have to hang up his gloves and find himself a new scientific field. He had shouldered his responsibility as a chemist.

"When you have knowledge you have a responsibility to use that knowledge wisely!

Ole John Nielsen


Dept of Chemistry

University of Copenhagen

“Each and every time we need a new chemical compound we need a chemist to synthesise it, and a chemist to analyse the fate of that compound in nature. And that gives a great responsibility to chemists. Because when you have knowledge you have a responsibility to use that knowledge wisely”, feels Ole John Nielsen.

But the Danish professor didn’t get to hang up his atmospheric gloves. The product that professor Nielsen had pronounced safe for ozone turned out to carry a different threat.

Replacement posed new and unpredicted threat

Though HFC 134a does not deplete stratospheric ozone it does prevent infrared radiation from escaping from the planet. In fact it turned out to have a global warming potential some 1.400 times larger than the baseline CO2. But this time the industry seemed prepared to come up with a better refrigerant and have it tested.

"I have seen a gigantic shift in attitude in my time... As I see it: Industries, especially big corporations, are acting much more responsibly today!

Ole John Nielsen


Dept of Chemistry

University of Copenhagen

“I have seen a gigantic shift in attitude in my time. Anyone wanting to produce a compound in quantity these days will ask someone like me to figure out what will happen to it in the atmosphere if it is released. Of course we also se legislation making it easier to prosecute anyone harming the environment, but as I see it: Industries, especially big corporations, are acting much more responsibly today”, says Nielsen.

Same fate as Freon

Nielsen was so proud of his work on HFC 134a that for years he was calling it “His compound”. But a global warming potential of 1.400 meant it had to go the way of Freon.

The compound slated to replace HFC 134a has also been tested by Nielsen. And it has a global warming potential of just four.

Next up, says Nielsen, are bio-fuels such as ethanol and bio butane.

“If they are to replace diesel and gasoline, we’d better be sure what they might get up to in the upper atmosphere”, says Ole John Nielsen.

No expectations for more Nobel laurels

Despite the fact that he has a framed Nobel Peace Prize certificate hanging on his office wall, the professor harbours no illusions about his chances of getting a Nobel Prize for his atmospheric chemistry work.

“There were 2.500 of us sharing that Nobel Peace Prize. So I had to watch the award ceremony on my laptop. And you know what? It was a great experience. And to be realistic, I never would have gotten the prize for chemistry. So I’ve got to appreciate the peace-prize. And who knows. Maybe it’s a more important one?” Smiles the reluctant laureate shyly.