Paris climate plans: international aviation and shipping

What are NDCs?

Nationally determined contributions (NDCs) are the plans states submit to the UNFCCC to show how they will reduce their greenhouse gas (GHG) emissions in line with the Paris Agreement. The deadline to submit the third round of NDCs was postponed from February to September 2025 since only 10 out of 195 states that are party to the Paris Agreement submitted their NDCs on time.

Are international shipping and aviation in NDCs?

While countries do generally account for domestic aviation and shipping in their NDCs, they largely ignore international aviation and shipping.

A common reason given is that states deal with international aviation and shipping emissions through other UN agencies, the International Maritime Organization (IMO) and International Civil Aviation Organization (ICAO). They think that they are therefore not obliged to include international aviation and shipping emissions in their NDCs.

However, the IMO and ICAO’s regulations have been slow to come into force and are not aligned with Paris Agreement climate targets. The net result is IAS emissions are ignored at the national level and not properly addressed at the international level, so fall through a regulatory gap – leading to international shipping being aligned with 3.4ºC of global heating and international aviation aligned with over 4ºC.

This is not just a failure of climate action: States are not meeting their legal obligations. States are compelled under international law to go take all necessary action to reduce emissions across their economies. This includes international aviation and shipping and means going beyond IMO and ICAO measures, insofar as those measures remain not good enough.

Opportunity Green uses the law to push for the inclusion of IAS emissions in States’ climate targets and NDCs. We have:

• Made a legal submission to the Aotearoa New Zealand Climate Change Commission outlining the legal obligation to include IAS in the country’s climate targets – we were pleased to see the Commission has now advised the government to update its target to include IAS;

• Submitted a written statement to the International Court of Justice’s advisory proceedings on climate change, outlining states’ legal obligations in respect of IAS emissions; and

• Submitted a written statement to the International Tribunal for the Law of the Sea’s advisory proceedings on climate change, outlining states’ legal obligations under the Law of the Sea to address shipping’s GHG emissions.