Aarhus Convention

The Aarhus Convention is a treaty between states that guarantees people certain rights in environmental matters. It was signed in 1998 in the Danish city of Aarhus, hence the name. The treaty rests on three pillars. First, anyone may request environmental data from authorities, such as air quality measurements. Second, citizens may have a say before an agency decides on a factory or a road. Third, one can go to court if an authority disregards these rights or breaks environmental rules.

Why environmental data should belong to everyone

Before the Convention, environmental protection was mainly a matter for authorities. Anyone who wanted to know how much pollutant a plant emitted often received no answer. The justification was usually that it was a trade secret or none of the public’s business. The Aarhus Convention reverses this logic. Disclosure is the default, and a refusal must be justified by the authority.

The idea behind this is simple. Environmental damage affects people on the ground, not the agencies in the capital. Those who are affected should therefore also be able to exert influence. To do so, they first need information, otherwise they cannot argue meaningfully at all. Experts call this principle environmental democracy.

For companies and investors, this is no side issue. Environmental organizations have already had permits for power plants, highways, and open-pit mines overturned on the basis of these rights. A project can fail legally even though the authority has long since approved it. That is why the Convention regularly appears in risk analyses for major construction projects.

The three pillars in detail

The first pillar is access to information. One submits an informal request to the responsible authority, usually an email is enough. No reason needs to be given, and that is the decisive point. In Germany, the Environmental Information Act implements this requirement. The authority must generally respond within one month.

The second pillar is participation. For larger projects, plans are made publicly available, and anyone can submit objections. Timing is important: participation must take place while all options are still open. A hearing held once the excavator is already rolling does not satisfy the Convention.

The third pillar is legal protection. It is the sharpest of the three, because it is what gives the other two their effect. Recognized environmental organizations may sue without being personally affected. This was long different under German law and had to be changed after several rulings by the European Court of Justice. A common misconception, by the way, is that the Convention prescribes specific limit values. It only regulates procedure, not content.

From wind farms to data centers

In everyday life, one encounters the Convention whenever something big is being built. Wind farms, power lines, chemical plants, and new railway lines all go through such participation procedures. Local residents also make use of them, for instance to review noise studies for a planned bypass road. Portals such as the Federal Environment Agency now put much of this data online on their own initiative.

New is the connection to the tech industry. Data centers for artificial intelligence consume large amounts of electricity and cooling water. Wherever one is to be built, the same rules apply as for a factory. Residents and organizations can request consumption figures and file objections. In Ireland and the Netherlands, such procedures have already delayed individual projects.

In the news, the Convention usually appears under keywords such as association lawsuit or right to environmental information. Related, but not the same, is the Freedom of Information Act. It applies to all administrative records, whereas the Aarhus rules cover only environmental topics, but are stricter there.