Travel agencies run maple-leaf tours and maple-leaf weekend breaks. The Buddhist temples are crammed with amateur cameramen photographing the most elegant specimens. The leaves are celebrated as much for their transience as their beauty - by the end of November, the trees are bare, the paths are swept and the leaves float up in the smoke of countless bonfires.But not this year. As the UN's conference on global warming rolls towards its uncertain conclusion, Kyoto is obliging environmentalists by experiencing unprecedentedly warm weather. Since delegates arrived a week ago, there has been one brief snowfall: for the rest of the time conditions have been almost spring-like, with sunshine, clear skies and temperatures as high as 21C. The autumn colours are still blazing, and the hills around the city have wide patches of green.Between 1986 and 1996, according to statistics gathered by Friends of the Earth, the average December temperature of Kyoto was 5.3C to 8.4C, with an average maximum of 12.9C. This year they have gone as high as 21C: activists have little doubt about the cause. "It's another side of global warming," says Tony Juniper, of Friends of the Earth.

"When Al Gore arrives tomorrow in his air-conditioned limousine, and drives up to his air-conditioned hotel for his carefully controlled meeting, I hope he'll consider the uncontrolled things that are happening in the outside world."Whether Kyoto's winter warmth is really a result of global warming or just a random weather variation is difficult to prove. But the autumn colours are not the only Japanese symbol to suffer from rising temperatures. This year the mantle of snow on the volcanic cone of Mt Fuji is thinner than ever and a creeper known as pioneer plant is crawling higher up the mountain, in areas which used to be skiing grounds. "I started caring for this mountain around 1947," said Tei Takagi, a former forestry officer who lives near it. "At that time, come October and November, the mountain would be covered with about two metres of snow."Recently, it has been sparse even on the 3,776m summit, where the average temperature has risen to -8.3C, compared with -10.7C in the 1940s.. The Government says Britain will cut its carbon dioxide pollution by 20 per cent by 2010. In the first of a two-part series, Nicholas Schoon asks if ministers are serious about this target - and, if so, how can it be reached? It was there in black and white in the party's manifesto, and has been repeated since the election by Tony Blair.

Britain will cut its annual emissions of the main greenhouse gas to 80 per cent of its 1990 level over the next dozen years. It remains to be seen if this target survives very long after the rest of the developed world signs up in Kyoto to far more modest cuts on Wednesday. But the fact is that Britain could do it, and lead the world in tackling climate change. It would change the life of every family and the workings of most businesses over the next 10 years. Wind turbines would become as common as high- tension pylons.We would have a cleaner country, since other kinds of pollution would reduce sharply, and a more efficient one. Our cities might be a little more densely packed, and our economy would continue to grow. In fact, it might make Britain rather more like Japan.UK emissions have fallen by 5 per cent since 1990, due mainly to changes in the way we generate electricity. The proportion which comes from burning coal has fallen drastically.