By 2030, 50 percent less nitrogen must be emitted and so farmers will have to make them more sustainable, shrink or even stop. Opponents — furious farmers and much of the VVD supporters — use the main argument that nitrogen rates are based on calculation models and not on measurements. What about that?
First of all: Nitrogen contains nitrogen oxides and ammonia that are harmful to nature. Nitrogen oxides are mainly emitted by traffic and industry. Ammonia mainly comes from livestock farming.
To calculate where the most nitrogen amounts to, there is a calculation model. Nitrogen professor Jan Willem Erisman explains:
“Its a distribution model. This includes all sources of nitrogen: traffic, industry, Schiphol. farms, the number of cows, pigs and chickens, etc. The model then calculates the distribution of nitrogen and where that amounts to in the nature reserves. So the model provides insight into all individual sources and calculates how you can achieve the desired nitrogen reduction.”
The green areas have to do the most about nitrogen emissions:
Is the model never wrong?
“Its about the whole of the Netherlands. For all areas, you can accurately calculate the rainfall. The desired reduction is introduced and then you check for each area if the targets are met.”
Cant it be more accurate? Not with a model, but with real measurements?
“That would be ideal. But it involves a lot of resources. That cannot be done with measurements. However, measurements are used to check the model. There have been many measurements to calibrate the calculation model. But it is not possible to measure alone. We can make a first blow with the use of satellites, but with that you only measure ammonia concentration, but not where it comes down.”
Could farmers measure at farm level?
“It is calculated how much reduction has to take place per area. A farmer can measure whether his measures lead to a reduction. That is possible in the long run But such a measurement now costs a few tons per farm. We must first develop these measurements further.”
Will measurements lead to different policies?
“Models will not change with more measurements. Measuring more does not result in other outcomes. Were going to have to do with this. Farmers also have to see what they can do to contribute to the nitrogen reduction.”
Farmers dont want to sell their land to reduce nitrogen emissions. What if you have to?