The suggestions are part of the fourth review of Portugal's environmental performance released by the Organisation for Economic Cooperation and Development (OECD), in which the organization of 38 countries analyses the country's environmental performance over the last decade and makes 26 recommendations.

To improve this performance, it is necessary "to transfer investment from building new roads to improving the rail network".

And Portugal, suggests the organization, should consider introducing taxes based on the number and type of animals and the use of fertilizers, and divert public support from activities with high-intensity emissions in the agricultural sector.

It is necessary, reinforces the OECD document, to increase the rates of water abstraction for agriculture, reinforce the monitoring of abstractions and limit new licenses in certain regions, and "accelerate the transfer of the costs of managing urban waste to families through identifiable specific charges, dissociated from the water bill".

Green tax reform

Portugal must also complete the assessment of the green tax reform, "with a view to a more consistent application of the polluter pays principle", closing the tax difference between diesel and gasoline, promoting less polluting vehicles, varying toll prices "in function of vehicle emissions" and develop low-emission zones in cities.

It is necessary, says the document, to continue to support the acquisition of vehicles with low carbon emissions and to accelerate the implementation of charging stations throughout the country.