There are two scenarios under which a country may need to update its NDC:
- Low ambition scenario. The emissions reductions considered in the NDC are too low or even including hot air, and the country goes well beyond its commitment. Emissions reductions would be considered as low integrity in a CAT agreement, and the NDC would need to be adjusted. This scenario should be avoided by not entering into CATs with countries whose NDC are seen as unambitious.
- High ambition scenario. The host country had considered emissions reductions in the NDC that are too costly or unachievable even after putting in place the policies and measures anticipated. Therefore, no mitigation units are generated for transfer to CAT partners. An upwards adjustment of the NDC may be contested by multiple stakeholders in the UN process, host and partner country citizens or environmental NGOs. Again, the CAT agreement must cover a risk sharing scenario under circumstances where the host country can show that it implemented all policies originally envisaged to fulfil its NDC target, and thus proves that the ITMO shortfall is not due to ‘negligence’.