On the strength of its expertise in handling national air emissions inventories in compliance with UN rules, CITEPA is authorised to carry out audits (or international reviews) of pollutant emission inventories produced by EU Member States or other countries to support the work of the United Nations Economic Commission for Europe (UNECE), and of greenhouse gas (GHG) emission inventories produced by the Parties to the United Nations Framework Convention on Climate Change (UNFCCC). Three CITEPA engineers have United Nations authorisation to conduct audits of GHG inventories.

CITEPA shares its expert knowledge on implementing systems for integrated inventories of pollutant and greenhouse gas emissions. It supports countries in building their capacities to implement efficient emissions inventory systems and in optimising the necessary resources. In 2013 and 2014, for example, CITEPA worked for Serbia under a France-Serbia twinning programme, and for Colombia after winning a call for tenders and has been involved in other specific projects in the country. Similarly, work on implementing a system for integrated emissions inventories in Mexico began in 2014.

Many non-Annex 1 countries are looking to make progress, on a voluntary basis, with GHG emission reductions and the implementation of nationally appropriate mitigation actions (NAMAs). CITEPA is well qualified to address such needs. For example, it recently completed a mission in Tunisia commissioned by Germany's international cooperation agency GIZ (Gesellschaft für Internationale Zusammenarbeit) to produce an exhaustive diagnosis of Tunisia's GHG inventory and MRV (Monitoring, Reporting, Verification) systems. It is now helping Tunisia to improve its inventory system as a whole and auditing several NAMAs.

CITEPA takes part in international consortiums and also launches others to respond to international calls for tenders from the European Commission, the World Bank or the United Nations Environment Programme (UNEP). It is thus in a position to share its expert knowledge on a range of topics with administrative bodies in other countries, but also with their industries. These topics include preparatory techno-economic studies for implementing new regulations, emission projections, etc.