Richard Sambrook, Director BBC Global News, offers an essential survival strategy for public broadcasters

There is an apocryphal Chinese curse: "May you live in interesting times." It is intended to condemn the subject to challenge and uncertainty. For anyone who is involved in the future of global journalism, we certainly live in interesting times - but sometimes the most challenging can also be the most rewarding.

Anyone seeking to determine the future of news has to contend with some difficult cross-currents.

First, the impact of globalisation.This has meant that world events can have a local impact and vice versa. Take, for example, global warming. Scientists are increasingly concerned that there may be an imminent shift in the world's climate and that this can be linked directly to energy policy in individual countries. If they are correct, ways of life in the north will change fundamentally and the balance between countries with and without natural resources will change, too.

Or the global economy, with the rise of Asia and rich Western countries "offshoring" manufacturing, and increasingly service jobs. This changes patterns of work and the quality of life around the world.

Or the Middle East, where political tensions have had a devastating impact on the streets of New York, London, Madrid, Istanbul and Bali; where the frustration and disillusion of the Arab world have found expression among young people across the UK and elsewhere.

Certainly as audiences confront a confusing and often frightening globalised world, they need information that they can rely upon and trust

The second cross-current is technology, which allows people to access news in a variety of different ways, providing additional sources of information and opinion, and undermining the traditional sources of news around the world.

News is now available not only on paper and via television and radio, but increasingly via the internet, mobile phones and other devices, with a wealth of competition. As I write, the Arab news channel al-Jazeera is about to launch in English; Russia is about to launch an English-language global news channel; there will be a "French CNN" by the end of 2006; a group of developing countries has joined forces to try to launch its own global channel; and on the internet a new blog is launched every minute.

A third cross-current is the impact of all of this change on major news organisations, calling into question their values and purpose. Journalism is not held in high regard in many parts of the world. From world leaders to the most humble consumer, there are those who question the motives and abilities of major consolidated media organisations to reflect properly their interests and world affairs.

However, in the swirl of these and other currents of change I believe there is a major opportunity for the BBC's global news services. We start with a number of advantages. BBC News is strong across all three media: radio, television and the internet. Each week, 190 million people around the world choose to get their news from the BBC - a larger number than tune in to any of our competitors. Crucially, repeated surveys show that they trust the BBC as an independent and reliable source of news - and that they usually trust us more than our international competitors.

That trust is built upon our editorial values, which have held good for nearly 75 years: truth and accuracy - facts based upon sound evidence and set in context; serving the public interest - reporting events of significance and striving to make them interesting and relevant; impartiality and diversity of opinion - testing a wide range of views; independence - from both state and commercial interests; and accountability - our first loyalty is to our audiences.

I believe those values will hold good through this period of enormous change. Certainly as audiences confront a confusing and often frightening globalised world, they need information that they can rely upon and trust. A news service that will explain the background and context of events without sensationalising them; programmes and services that put a premium on accurate information over opinion and comment.

As audiences adopt new technologies and devices, they will want a news service they can rely upon, whichever platform they choose to use. They will want to be able to find it easily and will expect it to be available whenever and wherever they choose to use it.

And as this new environment questions the standards of media throughout the world, news organisations that have a clear and public set of values and are open and accountable to the audience will earn their continued support and trust.

We do live in interesting times full of challenge and uncertainty. But I believe it's an environment in which the strengths of the BBC will be clearer and will provide better value than ever to our audiences around the world.