From Alaska to Australia, the world is changing in front of us

Europe

In Greenland the barley is growing for the first time since the Middle Ages. In Britain gardeners were warned this week that the English country garden will be a thing of the past within the next 20 years. In Italy skiers were told yesterday that melting glaciers will mean an end to their pastime unless they can get above 2,000 metres.

Even those enjoying the warmer temperatures in unpredictable bursts by venturing into the sea have been confronted by swarms of jellyfish, who have flourished in record numbers in Europe in the warmer waters. Those same waters are rising in Venice, prompting arguments over costly plans to seal off the lagoon from the sea.

The prospect of flooded squares on the scale of Venice's Piazza San Marco is driving plans to expand and reinforce the Thames flood barrier. In Holland the battle has been lost and 500,000 hectares, an area more than twice the size of greater London, will be strategically flooded instead and people will move to floating homes.

Last summer Spain and Portugal experienced cauldron-like temperatures and prolonged drought. This summer that drought has expanded into central and northern Europe.

Africa

The poorest continent has inevitably found itself on the frontline of climate change. Natural disasters, extreme weather floods and droughts have always been common in southern Africa but the severity of the wet and dry periods is intensifying with disastrous results.

A barrage of meteorological studies have found a pattern of increasing climatic variability and unpredictability. Throughout the Horn of Africa debilitating droughts this year have culled the region's wildlife and disrupted the migrations across the Masai Mara and the Serengeti.

Human populations have been devastated by the soaring temperatures and freak dry seasons. Herdsmen in the north of Kenya have been driven to war over the few cattle that have survived the drought.

The breaking of the drought has seen torrential flooding wreak havoc in Ethiopia's Omo Valley, home to numerous indigenous tribes. More than 800 people were killed last month and tens of thousands more made homeless after weeks of heavy rain following prolonged drought, which caused a number of rivers to burst their banks.

North America

In Alaska there has been millions of dollars of damage to buildings and roads caused by melting permafrost. The region has been blighted by the world's largest outbreak of spruce bark beetles, normally confined to warmer climes. Rising sea levels have forced the relocation of Inuit villages and polar bears have been drowning because of shrinking sea ice. The caribou population is in steep decline due to earlier spring and the west is suffering one of the worst droughts for 500 years.

In Louisiana about 1 million acres of wetlands have been lost to sea-level rise. In the north-west there has been dramatic shrinkage of glaciers in Glacier National Park and the South Cascade Glacier in Washington is at smallest size ever in the last 6,000 years. In the Rockies there has been a 16 per cent reduction in snowpack. Spring snow melt begins nine days earlier.

Hawaii has seen first large-scale coral bleaching. And scientists now believe that the strength of hurricanes that strike the south-east and the Caribbean is linked to climate change.

South America

Few images have offered such stark evidence of the advance of climate change as those of the dry bed of the Amazon river. Last year, the largest river in the world was reduced to a trickle by an unprecedented drought. This year sand banks have already appeared in the deltas of the Amazon and fears are rising that a drought cycle that was previously measured in multiples of decades may now be an annual event.

As the most important carbon sink in the world, the Amazon's impact on global patterns of rainfall is only now beginning to be fully understood and scientists warned in July that this extraordinary planetary air conditioner could be malfunctioning critically. The drying of the world's most biologically diverse forest has already been instrumental in a 1,000-fold increase in the extinction rate of plant and animal species, according to leading botanist Sir Ghillean Prance.

In the Peruvian Andes the alpacas that have for centuries provided indigenous farmers with a means of survival have died in cold snaps where temperatures plummeted to -30C. In the summer, melted glaciers revealed rock faces burnt red by their first contact with direct sunlight.

Australia

Al Gore's documentary, An Inconvenient Truth, twice singles out Australia for lagging behind the rest of the world on climate change. It has, along with the US, refused to ratify the Kyoto protocol. The Industry Minister, Ian Macfarlane, dismissed as "just entertainment" Mr Gore's film, which documents the scientific consensus that climate change in Australia has increased the duration and intensity of cyclones, and prompted a drop in rainfall in agricultural areas.

All around the region further evidence of climate change is to be found in the rising sea levels already starting to inundate Pacific islands, where the people, agricultural land, tourist resorts and infrastructure are concentrated on the coast. Temperature increases in the Pacific are killing off coral reefs. Some scientists say it is already too late to prevent their destruction.

Asia

Some of the most visible effects of climate change are in Asia. From the frozen wastes of Afghanistan, where the river bed in Kabul has become a dry rubbish tip, to south India, where thousands of farmers have killed themselves after successive years of drought wrecked their crops, global warming is a problem.

Most ominous of all, environmentalists are warning of disaster in the Himalayas, where glaciers are melting. Several glacier lakes have already burst in Nepal and Bhutan. The disappearance of the glaciers could dry up major rivers as far away as China, India and Vietnam.