A Nobel prize is the ultimate accolade. At a time when the cash-for-honours scandal has so tainted peerages and knighthoods that Tony Blair did not submit an honours list to mark his departure as Prime Minister and the awarding of top literary prizes is routinely soured by public score-settling among members of the judging panel, Alfred Nobel's legacy remains cherished more than a century after the first prizes were awarded.

A Nobel prize is the ultimate accolade. At a time when the cash-for-honours scandal has so tainted peerages and knighthoods that Tony Blair did not submit an honours list to mark his departure as Prime Minister and the awarding of top literary prizes is routinely soured by public score-settling among members of the judging panel, Alfred Nobel's legacy remains cherished more than a century after the first prizes were awarded.

In large measure, this is due to the conditions he laid down: the scientific, literary and economic laureates are decided by specialist panels in Sweden, which draw up shortlists on the advice of academic advisers. Unlike the biggest literary prizes and the Oscars, where the shortlists are regarded as free advertising, the shortlists are kept secret, even after the winner has been announced.

There is no record in the minutes of any Nobel Committee meetings of discussions relating to choices of candidates for the various awards and members of the panels are not allowed to take part in public discussions following the announcements.

While the combination of secrecy and large amounts of money is normally a warning signal for corruption or self-interest, in this instance it has been a recipe for independence and immunity from lobbying.

This year the specialist awards recognise ground-breaking work in chemistry and biology and a lifetime of pushing back the literary frontier, continuing Alfred Nobel's intention to honour those who have "conferred the greatest benefit on mankind" in the preceding year in the fields of physics, chemistry or medicine, peace and literature.

The Peace Prize, which has the greatest public impact, is not decided in Sweden, but in Norway, by a committee of five people elected by the Norwegian Parliament. Yesterday they awarded the prize to Al Gore and the UN's Intergovernmental Panel on Climate Change "for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change". That will not pass without controversy: it is a broad interpretation of Nobel's direction that the peace prize should go to the person who has done most "for the abolition or reduction of standing armies and for the holding and promotion of peace congresses". Over the years, however, the debate around the peace prize has served its wider aim; the resulting international stature of the laureates has aided the cause of individuals trying to bring about reconciliation in their own backyards. Closest to home are John Hume and David Trimble in 1998 and to Betty Williams and Mairead Corrigan, founders of the Northern Ireland Peace Movement, in 1976.

It can be argued that the extra clout which the prize confers provided another nudge towards the present power-sharing agreement at Stormont. Nobel, the inventor of dynamite, hoped, in vain, that the destructive power of his invention would bring an end to war: a prize for promoting peace was his posthumous way of realising that dream.

Against the odds, he has succeeded in handing on the baton.