In 2016, the government committed to achieve carbon neutrality by 2050, outlining a clear vision of decarbonisation of the national economy and contributing to the most ambitious objectives under the Paris Agreement. To support this commitment, the government decided to draw up a 2050 Carbon Neutrality Roadmap (RNC2050) with the aim of exploring the feasibility of trajectories that lead to carbon neutrality, identifying the main decarbonisation vectors and estimating the carbon reduction potential of various sectors of the national economy, such as energy and industry, mobility and transport, agriculture, forests and other land uses, and waste and waste water. This National Energy and Climate Plan is based on a strategic vision for the 2030 horizon of "Promoting the decarbonisation of the economy and the energy transition towards carbon neutrality in 2050 as an opportunity for the country, based on a democratic and fair model of territorial cohesion that enhances wealth generation and the efficient use of resources", being its decisive contribution to the definition of This report constitutes the 4th Biennial Report of Portugal, as required under Decision 2/CP.17 of the Conference of the Parties under the United Nations Framework Convention on Climate Change (UNFCCC) and Article 18(1) of the Regulation (EU) No 525/2013 of the European Parliament and the Council of 21 May 2013 on a mechanism for monitoring and reporting greenhouse gas emissions and for reporting other information at national and Union level relevant to climate change and repealing Decision No 280/2004/EC.