Background：

 The 21st session of the Conference of the Parties (COP21) to the United Nations Framework Convention on Climate Change (UNFCCC) held in 2015 adopted the Paris Agreement as the main international climate policy agreement for the post-2020 period (UNCCC, 2015).

Parties to the Paris Agreement communicate Nationally Determined Contributions (NDCs), which are pledges containing their contribution to the challenge of reducing global emissions and keeping end-of-century warming below 1.5 °C. There is no yardstick to measure the adequacy of NDCs or the actual progress towards them. Therefore, to measure progress on the implementation of countries’ policies and targets is essential to make the Paris Agreement work.

Most countries have updated their NDCs and adopted additional policies since the Paris Agreement came into force. The latest submitted targets are an improvement in comparison to the original ones but remain globally insufficient to curb global emissions (den Elzen et al., 2022a). Policies have also improved since 2015 but projections under currently adopted policies suggest emissions are still expected to increase up to 2030 (Nascimento et al., 2022). Despite these improvements, a global ambition gap exists between countries’ target and policies and the collective mitigation goals of the Paris Agreement. It is, therefore, crucial to continually track countries’ progress towards their NDCs and inform policymakers with up-to-date knowledge to ensure effective implementation of the ratcheting mechanism under the Paris Agreement.