Most of this work is undertaken through the ICAO Council's Committee on Aviation Environmental Protection (CAEP), which consists of Members and Observers from States, intergovernmental and non-governmental organizations representing aviation industry and environmental interests.

ICAO Assembly Resolution 35-5 endorsed the further development of an open emissions trading system for international civil aviation and requested the Council of ICAO to provide further guidance for States in this matter focussing on establishing the structural and legal basis for aviation's participation in an open trading system, and including key elements such as reporting, monitoring, and compliance, while providing flexibility to the maximum extent possible, consistent with the UNFCCC process. Accordingly, ICAO had prepared draft guidance on this subject. In September 2007 the ICAO Assembly adopted Resolution A36-22 in which it requested the ICAO Council to form a new Group on International Aviation and Climate Change. This Group is to be tasked with developing and recommending to the Council an aggressive Programme of Action on International Aviation and Climate Change.

A Consolidated Statement of continuing policies and practices related to environmental protection is revised and updated by the Council every three years for adoption by the ICAO Assembly. The present version, Assembly Resolution A36-22, was adopted in September 2007.

ICAO maintains close relations with other UN policy-making bodies that have expressed an interest in civil aviation, notably with the Conference of the Parties to the United Nations Framework Convention on Climate Change, to which it provides regular statements on ICAO's emission-related activities.

ICAO has produced a number of publications and held some organized workshops in this field.