While many are acquainted with the problems caused by CO­­2 emissions, the harmful effects of the release of nitrous oxide into the atmosphere have been far less well known. Only in recent years has the international scientific community begun to understand the scope of the threat posed by N2O emissions.

Biological fuel among the culprits

Emissions of nitrous oxide have evolved into a big problem following the boom in the production of biological fuels – considered an effective measure against global warming.

“Biological fuels are produced as an alternative fuel, intended to replace the burning of oil and gas and thereby reduce global warming. However, since the plants used in the production of biological fuels require fertiliser we cannot eliminate the emission of nitrous oxide; it is a by-product of the process,” explains Professor Lars Bakken, a group leader with the Nitrogen Group at the University of Life Sciences (UMB) in Ås, Norway.

“The end result is more or less zero gain,” he adds. “Nitrous oxide actually tips the balance in the direction of greater warming, undermining the promise of biological fuels as a means to effect cooling.”

Part of a large international environment

Thanks to the projects being carried out at UMB, Norway has become a key player in international research on nitrous oxide.

“Emissions of nitrous oxide represent a global problem, one that may become especially acute in rapidly developing countries like China. We need to pool our resources to come up with the best solutions,” says researcher Peter Dörsch, another of the Nitrogen Group’s three group leaders.

“Dynamic nitrogen research groups in the Nordic region and the rest of Europe are at the forefront of this area. Norway is working in close cooperation with Canada and the US – longtime leaders of this effort. We expect our colleagues in China to overtake us for good in about ten years,” Mr Dörsh adds.

The UMB Nitrogen Group has already established fruitful collaborative efforts with many leading universities in China.

A widespread problem in China

The Chinese authorities are very focused on securing their country’s food supply, and therefore provide subsidies for nitrogen-based fertilisers. This increases the use of nitrogen in farming and results in acidification of the soil. Cultivated fields are a direct source of nitrous oxide emissions. Moreover, a considerable amount of the nitrogen from fertiliser evaporates into ammonia, which later spills down onto surrounding forests as acid rain.

“The amount of nitrous oxide emissions from China is going to escalate in coming years,” states Lars Bakken.

The research group in Ås is currently engaged in a bilateral collaboration project with China. The project is funded under the Sustainable Innovation in Food and Bio-based Industries (BIONAER) programme of the Research Council of Norway.

Norway in the lead

“The Chinese have wonderfully talented researchers currently using the robotised incubation systems we developed here in Norway,” explains the third group leader, Åsa Frostegård.

YARA, the Norwegian world leading fertiliser producer, is also involved in the cooperation with the Chinese universities. YARA seeks to gain greater insight into how nitrous oxide is formed with an eye towards future product development.

“The sheer scale of the collaboration increases the likelihood of our success,” says Dr Joachim Lammel, Head of Product and Application R & D at YARA.

“The UMB Nitrogen Group is a first-rate example of how a small country can be perfectly capable of performing cutting-edge research at the global level. Their research also clearly illustrates how relatively basic research can lead to solutions that are targeted towards specific challenges,” said Kirsti Anker Nilssen, Senior Adviser of the BIONÆR programme.

Working with pH

The Nitrogen Group is about to publish a study of soil-acidification and the release of nitrous oxide from fields in Nepal and China. They have shown that the enzyme used by bacteria to process nitrous oxide into “harmless” nitrogen gas does not work at a low pH.

“In developing nations such as China, intensive cultivation of the soil can lead pH levels to fall. We are fairly certain that this will bump up emissions of nitrous oxide. Our study adds to the body of evidence attesting to the significance of the Earth’s acidity level on the environment, says Professor Frostegård.

“We have carried out extended tests as part of our research, experimenting with agricultural lime in China to see what the result would be,” Professor Bakken eagerly relates. At the same time, he stresses that there are even better alternatives to agricultural lime for decreasing the Earth’s pH value.