If European science is to prosper, the barriers that prevent seamless interactions between scientists in different nations need to come down. Last week, the European Commission published a 'green paper' on the future of the European Research Area, the entity it created to improve such interactions. Scientists must now engage in the consultation process that will follow from this document and so help resolve the problems that currently constrain 'cross-border' science.

The European Research Area is a somewhat nebulous concept, most readily described as the highly fragmented arena within which European Union scientists work, in both public and private sectors. But it is a concept that matters, in determining how easily a European researcher can operate across national borders.

Current deficiencies in the way the area works are most apparent when they are personal. One German biology professor, for example, was recently courted by a university in the Netherlands. Aware of the advantages the prestigious post held for his research ambitions, the professor was sufficiently enthusiastic to accept a small salary cut. But negotiations collapsed because Dutch regulations made it impossible for him to bring his German pension to the new position.

On a broader level, those seeking to create expensive items of scientific infrastructure to serve the whole continent, such as a biobank of gene or tissue samples, are often dismayed to find that there is no appropriate source of funding — no matter how useful the project. Scientists in Europe also find that the management of intellectual-property rights varies between the member states. Scores of issues such as these make it hard for researchers to properly exploit the scale of the European Research Area.

Overcoming such obstacles is rightly seen as important in the European Union's push to become more scientifically competitive with the United States, where scientists already enjoy the advantages of ready interaction with a vast array of colleagues in a nation of 300 million people.

It is important that the European Commission gains the explicit support of both industrial and academic scientists in its long march towards European research unity.

The green paper released by the European Commission on 4 April outlines the existing problems and asks for ideas from interested parties, including scientists, on what should be done to fix them. The consultation process will include a questionnaire that will appear on the commission's website (http://ec.europa.eu/research/era) from 1 May until August, and a conference in Portugal this autumn. Early next year, the commission will use this feedback to help it draw up decrees or legislation that it thinks will help strengthen the European Research Area.

But the commission does not have the clout to implement such reforms on its own. Its main political master, the Council of Ministers, committed itself in 2000 to improving competitivity in research and innovation by 2010 — by facilitating the mobility of researchers, for example. But the member states whose leaders make up the council have not yet implemented the changes in their home countries that are needed for the European Research Area to function effectively.

The European Commission, whose Framework research programmes still account for only about one-twentieth of the member states' total spending on research, can do little more than encourage national governments to realize that far more cooperation at the European level will benefit them all. Perhaps the most sensitive issue in this regard is to get more national tax revenue to be pooled for genuinely European projects.

None of these problems will be solved overnight. But it is important that the commission gains the explicit support of both industrial and academic scientists in its long march towards European research unity. The consultation will allow individual researchers to put on the record the cross-border issues that confront them in their working lives. As many as possible should fill in the questionnaire and make their voices heard.