The number of transboundary environmental impact assessment procedures is increasing

The Convention on Environmental Impact Assessment in a Transboundary Context (Espoo Convention) by the United Nations Economic Commission for Europe (UNECE) was adopted in Espoo on 25 February 1991. The convention promotes the rights of citizens and stakeholders to participate in environmental decision-making.

The Espoo Convention and its Protocol on Strategic Environmental Impact Assessment (The Protocol on SEA) oblige the parties to assess the potential transboundary environmental impacts of various projects and plans and programmes prepared by authorities, including land use plans, well before their implementation. The convention lays down the obligations of the parties to the convention to inform, consult and negotiate when the significant and likely environmental impacts of the activities may extend to the territory of other countries. The purpose of the environmental impact assessment (EIA) procedure is to investigate, mitigate or prevent the harmful environmental impacts of projects. The assessment of the effects of plans and programmes on the environment (SEA) refers to the assessment of the impacts of plans and programmes drawn up by authorities during their preparation phase.

The Finnish Environment Institute (Syke) has carried out information, negotiation and consultation tasks referred to in the Espoo Convention and the SEA Protocol in Finland since 2023. In this time, the number of transboundary EIA procedures has increased dramatically. A total of 77 procedures have been launched during Syke’s term of office in 2023–2025, which is around 40 per cent of all procedures initiated after 1996.

“EU countries’ investments in energy production projects related to the green transition, such as wind power, are increasing, and development is not expected to slow down in the coming years. This means that the number of international hearings will probably also increase,” says Jenni Juslén, Head of Services at the Finnish Environment Institute.

A total of 99 transboundary EIA procedures were ongoing at the end of 2025. A multi-stage process may take several years. During the process, the authorities and citizens of the relevant countries are consulted and issues related to environmental and health impacts are discussed.

Energy production is emphasised in project types

Most of the new transboundary EIA procedures are related to energy production projects, such as onshore and offshore wind power, nuclear power and hydrogen projects. Recently, completely new types of projects have also emerged.

“For example, last July, Sweden notified Finland of an EIA procedure for a project seeking a permit to extract polymetallic aggregates called manganese nodules from the bottom of the Bay of Bothnia in the Swedish EEZ. Finland has announced that it will participate in the EIA procedure of this project, allowing Finns to comment on the matter,” says Julianna Reunanen, Senior Officer at the Finnish Environment Institute.

Another recent new project type is nuclear power plants with small nuclear modular reactors. Transboundary EIA procedures concerning small modular reactors are under way for projects planned in the Nordic countries.

Sometimes a project has several countries of origin, and the impacts may also extend to several countries. Such multilateral EIA procedures are ongoing, for example for hydrogen pipeline routes related to energy independence and security of supply in Europe.

The Espoo Convention provides opportunities to exert influence

The Espoo Convention promotes citizens’ rights to participate in environmental decision-making. The aim is to ensure that residents and other parties in the affected area are informed about projects, plans and programmes that may affect their environment and can participate in the impact assessment and, consequently, in project planning. This way, Finns have the opportunity to give feedback and influence projects in other countries.

The Finnish Environment Institute announces all ongoing procedures on its website and publishes the referrals concerning them in lausuntopalvelu.fi. Syke also maintains the relevant websites in the environment.fi service.