Onbekend nitrogeen bedreigt aarde (en)

As the overwhelmingly dominant element in the atmosphere around us, and one of the four most common elements in living organisms, it gets surprisingly little attention. Especially when its impact on humans and the planet has been described, by a recent expert report, as "one of the biggest challenges of the 21th century".

Nitrogen makes up 78 % of the air we breathe. It is an essential building block in all living things. But its story demonstrates that it is possible to have too much of a good thing. Despite its life- giving benefits, nitrogen also poses a growing threat to humans.

That threat has now reached such proportions that "business as usual" is no longer a viable response. It was to address this issue that an EU-funded, five year project called "NitroEurope" was set up in 2006, bringing together 62 partner organisations from 24 countries.

Nitrogen in the air is harmless. To be used, it needs to be changed into "reactive nitrogen" (Nr). This transformation occurs mainly as a result of natural bacterial activity, or by human intervention in the form of chemical engineering. Perhaps the most familiar form of reactive nitrogen is in fertilisers.

Here, the beneficial effect of Nr is clearest. It is estimated that, if humans had not started using it in fertiliser in the early 1900s, half of today's population would not be alive.

But excess quantities of reactive nitrogen cause a range of problems. It damages soil and water quality, pollutes the air and contributes to the greenhouse effect. Nitrates in water affect human health, increasing the risk of bowel cancer. In the air, reactive nitrogen creates pollutants which can lead to respiratory and heart disease.

All of which explains why the recently published European Nitrogen Assessment, to which NitroEurope made a major contribution, described the issue as one of the biggest challenges of the 21st century.

In order to tackle the problem, it is important to understand it. This was the primary aim of the NitroEurope project - studying the Nr issue in unprecedented detail, in order to understand exactly how Nr behaves and impacts the environment.

One achievement of the € 27 million project was the establishment of a "European Nitrogen Budget". This showed that Europe produces 15.6 million tons of Nr per year, with almost three quarters coming from fertilisers. The remainder is produced by combustion from transport or industrial processes.

The researchers were able to put an economic value on the effects of nitrogen pollution, estimating the total cost of the impact on human health, biodiversity and climate change at as much as € 320 billion per year. Meanwhile, air particles based on Nr are reckoned to reduce average European life expectancy by six months.

The project also revealed that, of the reactive nitrogen present in crops in Europe, only 15 % is used to feed humans directly, with 85 % used to feed animals.

From this, a key conclusion was clear. Reducing meat and dairy consumption would provide a major part of the solution to the world's nitrogen problem.

The Nr threat is clear. But so, too, is the way forward. As a result of the understanding created by the work of NitroEurope, there is no reason why humanity cannot now start to tackle this major 21st century challenge.

Project details

Participants: Poland, Hungary, Netherlands, Germany, Italy, Estonia, Denmark, Switzerland, Spain, Sweden, Norway, France, Russian Federation, China, Zimbabwe, Belgium, Ukraine, Ireland, United Kingdom (Coordinator), Slovakia, Croatia, Finland, Austria, Portugal

FP6 Project N° 17841

Total costs: € 26 970 000

EU contribution: € 16 600 000

Duration: February 2006 - April 2011