Al Gore, the former US vice-president and winner of the Nobel Peace Prize for his work on the dangers of climate change, called on the world yesterday to focus more on global warming and less on celebrities, in particular, O J Simpson, Paris Hilton and Anna Nicole Smith.

He named the jailed ex-All American football player, the attention-seeking hotel heiress and the late sex symbol to thousands of delegates at the UN climate conference at Poznan in Poland, as distractions from the greatest crisis the world had ever faced. Mr Gore appealed for people to be optimistic about the possibility of concluding a new climate treaty at the UN meeting in Copenhagen a year from now, saying the election of Barack Obama as President would mean that the United States would once more "engage vigorously" with the negotiating process, from which George W Bush withdrew.

He said: "We have to overcome the paralysis that has prevented us from acting and focus clearly and unblinkingly on this crisis, rather than on spending so much time on O J Simpson, and Paris Hilton and Anna Nicole Smith."

Download the new Independent Premium app Sharing the full story, not just the headlines

Mr Gore called for the world to aim for a new and much more stringent target for cutting the greenhouse gas emissions which are causing global warming; the present target, of 450 parts per million of carbon dioxide in the atmosphere, should be cut back to 350ppm, he said, a figure which the world has already passed (the present level is more than 380ppm).