Nairobi's motorists didn't know what hit them. The streets were being clogged by a new traffic obstacle, a stream of proud Maasai herders driving cattle before them. The spear-wielding pastoralists had come to the Kenyan capital out of sheer desperation.
The normally lush pastures of their homelands had been burned to a crisp, and grass remained in only one place, the suburban hedgerows and public parks of Nairobi.
"This is not a good place for us to be," one herder admitted one sunny afternoon as his cattle chewed up a city park. "But it's all that's left."
Drastic climate swings have devastated large swathes of Africa in the last five years. In the Horn of Africa the torrential El Nino rains of 1998 flooded neighbourhoods, tore up roads and destroyed property. No sooner had the waters subsided, than a drought set in and lasted two years, triggering famines in Kenya, Ethiopia and Somalia in 2000.
Meanwhile to the south the problem was too much rain. Mozambique was battered by storms that brought devastating floods in their wake.
Frustrated Africans began to wonder why God had visited such unpredictable calamities upon them.
But a growing body of Western opinion says man is responsible, and, in particular, the captains of Western industry.
Although Africa is responsible for only 3.2 per cent of world carbon-dioxide emissions, it is being hardest hit by temperature rises. "It is a very dramatic situation," said Mr Klaus Toepfer, executive director of the UN Environment Programme (UNEP).
The creeping onslaught of global warming is visible on top of Mount Kilimanjaro, Africa's highest peak. Its defining feature is a crown of ice and snow.
But the ice-cap is in danger of disappearing. The glacier will evaporate in less than 15 years, an American scientist, Dr Lonnie Thompson, warned earlier this year. The principal culprit, he said, was the harmful emissions from rich countries thousands of miles away.
"It matches so many other lines of evidence of warming," he told the New York Times.
"Whether you're talking about bore-hole temperatures, shrinking Arctic sea ice or glaciers, they're telling the same story. The rising temperatures will destroy the beauty of Africa." In May South African scientists warned that moderate global warming would trigger a large drop in agricultural production across sub-Saharan Africa.
Large swathes of savannah are being turned to desert in southern Somalia, where 10 years of war have allowed the destructive charcoal business to boom.
Most of the fuel is exported to Saudi Arabia and other Gulf states where, ironically, charcoal production is strictly controlled for environmental reasons.
In West Africa local and foreign logging companies are pulling down rainforests, threatening not only a valuable resource but also many species of rare animal. All of the world's great apes, which are found in these forests, will be destroyed within 10 years, according to the primatologist Mrs Jane Goodall.
"It's a very, very grim picture," she said recently in Nairobi. "There is an awakening everywhere, but I don't know if it's going to be on time."
Tomorrow: Climate change has claimed the lives of 50,000 people in Latin America over three years. Michael McCaughan reports