The European Commission (EC) has urged local authorities to overhaul their procurement policies in the wake of a damning report.
Less than one in five public bodies across the EU consider the environment for more than half their buying decisions, according to the research.
Yet these administrations spend around £1.5 billion more than 16% of the unions GDP on goods and services.
So the EC last week published its Handbook on Green Public Procurement to encourage more sustainable purchasing.
European Commissioner for the Environment Margot Wallström said: Public authorities have enormous purchasing power. If, for example, all public authorities in the union switched to green electricity, it would save 60 million tonnes of CO2, or 18% of the EUs Kyoto commitment on cutting greenhouse gas emissions by 2012.
Internal Market Commissioner Frits Bolkestein added: This handbook provides clear and practical guidance to local, regional and other contracting authorities in the process of dealing with the possibilities created by the public procurement directives.
With this handbook we respond to the needs of all these authorities to take action to protect the environment by using public demand. I hope that the handbook will also encourage the sharing of best practices and experiences to further green procurement policies. In this respect, the Handbook already presents practical examples taken from a wide range of authorities across the EU.
The EU adopted the Public Procurement Directives in March, imposing competitive tendering for public contracts above a certain value, transparency and equal treatment for all tenderers.
The EC insists the directives make it clear that public authorities can adopt environmental considerations into their procurement procedures in many ways.
Major barriers to procurement are said to be the lack of knowledge to set the right environmental criteria in tender documents, budgetary constraints due to the higher price of some green products and services, and legal uncertainty.
The Handbook seeks to help overcome these barriers by explaining in non-technical terms how to introduce environmental considerations in the different stages of procurement.
It insists on the importance of taking into account the life cycle cost of the purchased products, services and works, and it refers to an online database.