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The Convention and its achievements

A common framework for transboundary cooperation on air pollution

When scientists in the 1960s investigated the causes of the “acid rain” that was destroying forests, causing fish loss in lakes and putting entire ecosystems at risks in the Northern Hemisphere, they found that air pollutants, a significant part of which were emitted thousands of kilometres away, were the culprit.

In order to solve this problem, 32 countries in the pan-European region decided to cooperate to reduce air pollution. In 1979, they  signed the UNECE Convention on Long-range Transboundary Air Pollution, creating the first international treaty to deal with air pollution on a broad regional basis. The Convention entered into force in 1983, laying down the general principles of international cooperation for air pollution abatement and setting up an institutional framework which has since brought together research and policy. Over the years, the number of substances covered by the Convention and its protocols has been gradually extended, notably to ground-level ozone, persistent organic pollutants, heavy metals and particulate matter.

The Convention has substantially contributed to the development of international environmental law and has created the essential framework for controlling and reducing the damage to human health and the environment caused by transboundary air pollution. It is a successful example of what can be achieved through intergovernmental cooperation.





Text of the Convention 




Status of Ratification

Emission reductions

The result of this collective effort has been remarkable: emissions of a series of harmful substances have been reduced by 40 to 80% since 1990 in Europe. In particular, the decrease in sulphur emissions has led to healthier and forest soils. The drop in emissions has reduced the deposition of acidifying compounds to levels below critical loads of acidity in large parts of Europe.

Nitrogen emissions have also been reduced, although to a lesser extent than sulphur emissions. Hence, in areas in Europe where acidification of forest soils is still a problem, these exceedances are mainly due to deposition of nitrogen compounds.

The efforts to reduce nitrogen oxides emissions led to a  decrease in lead pollution. Lead pollution levels in the UNECE countries were reduced by almost 80% between 1990 and 2012. The highest reduction rates took place in the beginning of the period, reaching 15-18% per year in a number of countries (e.g., Finland, Denmark, Germany, Spain, Norway etc.). 

Air pollution emissions in the ECE-region between 1990 and 2012 (excluding Canada and the United States of America). Sulphur has the steepest decline (Source: EMEP-Centre for Emission Inventories and Projections) 

A common scientific understanding 

Important for the success of the Convention in air pollution abatement was its solid scientific underpinning. This was established through the development of a common knowledge base including a scientific infrastructure aimed at joint monitoring and modelling programmes, including an extensive international network of scientists of various disciplines. In addition, the Convention has provided a platform for scientists and policymakers to exchange informationwhich has led to innovative approaches.creating mutual trust and learning. 

While the first protocols developed under the Convention focused on technologies to reduce emissions, protocols negotiated in the 1990s used an effects-oriented approach, aiming at the most cost-effective way to reach reduction targets. At the same, it was also recognized that various air pollutants interact in the atmosphere, that they lead to combined impacts and that they often are caused by the same sources. This made a substance-by-substance approach less efficient and was the reason to develop a so-called multi-pollutant-multi-effect approach. The first protocol that used this new approach was the 1999 Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone (Gothenburg Protocol).

Looking ahead

Air pollutants know no borders, which is why international coordination of air pollution policy remains indispensable. 

Ratification and implementation of the Convention and its protocols will, for many Parties, reduce health and environmental impacts in a more cost-effective way than with unilateral action. It will also create economic benefits as harmonized legislation and standards across borders will introduce a level playing field for industry across countries and prevent Parties to compete with each other at the expense of environment and health. 

One of the priorities for the Convention in recent years has been the strengthened implementation of the Convention and its protocols, targeting more specifically Parties from Eastern, South-Eastern Europe, the Caucasus and Central Asia. In this regard, an assistance programme is being undertaken to raise the political profile of the Convention in the region and to encourage ratification of the Convention’s protocols. Recent amendments to the Convention’s key protocols offer flexibilities to facilitate accession by new Parties. For example, a Party to the Convention that joins the Gothenburg Protocol before the end of 2019 has flexibility to postpone the application of emission limit values by up to 15 years after the entry into force of the amended Protocol.

Air pollution affects all of us: it harms human health, affects food security, hinders economic development, contributes to climate change and degrades the environment upon which our very livelihoods depend. The Convention provides a platform to discuss these interconnections and take actions to prevent negative impacts (link to cross-sectoral pages).