Fun and philosophy at the BA talkfest

Next week sees the start of one of the year's most important meetings for scientists. Martin Rees is looking forward to it

Next week, the British Association for the Advancement of Science (BA) starts its annual meeting. The event, to be held this year at the University of Newcastle, offers a week-long festival of science. Some of the best scientists and presenters of popular science in Britain today will discuss and demonstrate just about everything, from "weighing" elusive sub-nuclear particles called neutrinos through the environmental causes of cancer to "The lost rocks of northern England". There will also be plenty of opportunities for hands-on exploration of basic scientific concepts and ideas.

As this year's president of the BA, I expect to find it fun (as I am sure all the participants will) and exhausting, too. Amid the festivities, I hope there will also be time for reflection about the place of science in Britain today.

One key might lie in an older nickname for the meeting than "festival". It has also been called the Parliament of Science. And there is the issue: in this most scientific and technological of times, what role and influence do Britain's scientists have among civil servants, politicians, policy- makers and opinion formers in wider society?

In the immediate post-war years, after the atomic bombs at Hiroshima and Nagasaki, scientists played a prominent role on the national and international stage. The priority was to alert the world to the dangers of the nuclear arms race, and the urgency of arms control. These issues may now have slipped down the agenda - the world is on a less short nuclear fuse than before. But a daunting range of new threats demands a similar commitment from the present scientific community.

Even in the worst phases of the Cold War, scientists maintained a substantial East-West dialogue. Regular discussion on security issues took place, for instance, at the Pugwash conferences, which were especially influential in the Sixties.

Other informal channels opened up later. One of the most effective has been between the US National Academy of Sciences and its Russian counterpart - expert groups from these bodies have met regularly since the Seventies, reporting back informally to their governments. Many of the participants - those who were involved in the SDI or "Star Wars" debate - now hold official posts in the US or Russia.

In the US, the Los Alamos generation of physicists (those who actually built the bomb) is being replaced by an equally impressive cohort of younger scientists, people who've done a spell in government, or in high-tech industry, and who serve regularly as consultants to the Defense Department or on advisory committees.

The US system offers academic scientists other routes to intensive involvement in public policy. Several US universities run part-time programmes on international security, aimed primarily at scientists. There is also the Jason group - physicists of the highest academic repute who meet regularly for several weeks per year, bringing fresh minds to bear on issues relevant to the Defense Department.

The younger Americans with this expertise, my own post-war generation, have no real counterparts here. We depend precariously on distinguished figures from the war generation, including Professor Joseph Rotblat (a founder, and now president, of the Pugwash Movement who will give a public lecture at the British Association next week).

The reasons for this transatlantic asymmetry aren't hard to find. In the US, senior staff can shuttle between government jobs and universities (or organisations such as the Brookings Institute), whenever the administration changes. Over here, on the other hand, government service is generally a lifetime career, and the more pervasive secrecy inhibits contact and discussion. On a personal level, my academic research has brought contact with many scientists from Los Alamos and Livermore (who attend academic conferences, and contribute to the open literature), but with none of their UK counterparts.

The meagre input of scientists into our political process is often bemoaned. It precludes a broad and well-informed debate on technical issues where well-thought-out new ideas are needed - energy, environment, and transport policy, as well as defence. The Government could follow the American example, and set up "Jason-style" groups - leading scientists from academe or industry who would not merely sit on advisory committees of the great and the good, but would commit themselves to carry out serious cross-disciplinary studies. This is, perhaps, an innovation the Government's new chief scientific adviser might consider. Another unmet need is a forum or institution that could fulfil, in the scientific and technical arena, a role similar to (for instance) that of Chatham House in foreign policy.

In so far as their expertise offers them special insight, scientists have an obligation to warn and influence government and the public generally. In the Cold War era, many of the "atomic scientists" conspicuously fulfilled this obligation. Current concerns are much more diverse, and should draw in many more people. Defence issues still rank high, but now there are other global concerns - threats without enemies. These are the interlinked issues of environment, resources, and biodiversity, and how these can be safeguarded without jeopardising the developmental aspirations of the poorer nations.

The UK has impressive credentials and a high international profile in the broad range of expertise that these global problems entail - problems that should loom as large in the political perspective as did the East- West political divide in the Cold War era.

Sir Martin Rees, the Astronomer Royal, is this year's president of the British Association for the Advancement of Science. The BA's annual meeting is at Newcastle University, 9 to 15 September. Information: 0171-973 3500.