<p>Way above us in the Himalayan cloud are jagged, snowbound peaks – Annapurna, Damodar, Gangapurna, Dhalguri. Below us is the Thulagi glacier, a river of ancient ice snaking steeply down the Marshyangdi valley from near the top of Mount Manasulu.<br />Thulagi is one of 20 steadily growing glacial lakes in Nepal which mountain communities and scientists fear will inevitably rupture if the growth in greenhouse gas emissions is not stemmed. Average temperatures across Nepal have risen 1.6C in 50 years – twice the global average. But here on the roof of the world, in what is called the “third pole”, they are already nearly 4C above normal and on track to rise by as much as 8C by 2050. <br /><br />Lives of one-in-four affected<br />Temperature rises like this in the Himalayas would be a catastrophe. It is not just the future of a few mountain communities at stake, but the lives of nearly one in four people in the world, all of whom rely on the Himalayas for water. Nepalese rivers alone provide water for 700 million people in India and Bangladesh. <br /><br />On a 1,000-mile journey from the world’s greatest water source in the Himalayas, down rivers and then by train through Nepal, India and Bangladesh to the Bay of Bengal, we saw evidence of profound changes in weather patterns right across south Asia. The starting point was Jomsom, a small town in the Kali Gandaki valley, 2,300 metres high and at the heart of the Annapurna range. This remote town, which saw its first ever car last year, has experienced no snowfall this winter. The temperature soared way above normal to 27C, and only fell to 13C, against a usual -4C, while the snowline has risen above 5,000 metres. The Gandaki river, fed by 1,200 glaciers, flows to the Ganges and on to Bangladesh. <br /><br />Nepal’s story<br />It’s the same story even in the Everest valley region, 400 miles to the east of Jomsom, where the snowfall is becoming increasingly unpredictable. Two hundred miles away in Nepal’s capital, Kathmandu, Simon Lucas, a climate change officer at the UK Department for International Development, confirmed that river flows in winter have seriously declined. “The trends are clearer in Nepal than in other countries,” he said. “People cannot plant their crops in the spring because the winter snows are not so heavy. They have always relied on snow and glacier melt.”<br />Britain earmarked £50m for Nepal to adapt to climate change, mainly through investing in its forests, but climate scientists say it faces ever more erratic, intense and unpredictable rainfall. We found the evidence for that when we headed south towards Nepal’s border with Bihar in India. Here the problem is not too little water but far too much; last year, following torrential monsoon rains, Nepal’s greatest river, the Khosi, broke though two kilometres of embankment and flooded hundreds of square kilometres of farmland. Nearly 1,500 people died and three million people were displaced. Fifty thousand people in Nepal and many more in India lost their homes, and the river changed its course by more than 150km. <br /><br />From severe flood to deep drought<br />We crossed the Indian border and went straight from severe flood to deep drought. Bihar, one of India’s poorest states, is experiencing one of its worst droughts in a generation. This year it has had only 15-30 per cent of its usual rains. “Climate change is definitely happening,” said Vyas Ji, principal secretary in the department of disaster management in Patna. We headed to Kolkata, one of India’s great cities, which was warned again by scientists that it was acutely vulnerable to sea level rises. <br /><br />“Climate change is not the future. It is now. Tens of thousands of Indians are already in a critical situation,” said Sugata Hazra, director of Jadavpur University's school of oceanography in Kolkata. His researchers have recorded sea levels in the Bay of Bengal rising far faster than the global average, and more cyclones hammering the coast. The result is the inundation of islands from higher tides and surges.<br /><br />To the Bangladeshi border<br />From Kolkata, we headed to the Bangladeshi border. Bangladesh is by far the most densely populated large country in the world and, being entirely on a low-lying delta, it is one of the most vulnerable. It stands to lose 20 per cent of its land to sea level rise in the next 80 years and is already experiencing more frequent and more intense cyclones. In the last seven years, four of the most powerful storms ever recorded have slammed its coasts.<br /><br />Our south Asian climate odyssey from source to sea ended south of Chittagong, on the Bay of Bengal. <br /><br />There, where the waters of the Kali Gandaki, the Ganges and Nepal’s many other rivers reach the ocean, communities are experiencing higher tides and more flooding, as well as the loss of farmland and fishing.<br /><br />“The sea water now comes right into our houses. We would all like to move, but there is nowhere to go,” said Geeta Das, a teacher in Bolihut village, near Chittagong. Her home has been partly washed away and her bed is now just a foot from where the waters reached a few weeks ago. "We panic when it is cloudy and it is about to rain. We fear we will lose our children."</p>
<p>Way above us in the Himalayan cloud are jagged, snowbound peaks – Annapurna, Damodar, Gangapurna, Dhalguri. Below us is the Thulagi glacier, a river of ancient ice snaking steeply down the Marshyangdi valley from near the top of Mount Manasulu.<br />Thulagi is one of 20 steadily growing glacial lakes in Nepal which mountain communities and scientists fear will inevitably rupture if the growth in greenhouse gas emissions is not stemmed. Average temperatures across Nepal have risen 1.6C in 50 years – twice the global average. But here on the roof of the world, in what is called the “third pole”, they are already nearly 4C above normal and on track to rise by as much as 8C by 2050. <br /><br />Lives of one-in-four affected<br />Temperature rises like this in the Himalayas would be a catastrophe. It is not just the future of a few mountain communities at stake, but the lives of nearly one in four people in the world, all of whom rely on the Himalayas for water. Nepalese rivers alone provide water for 700 million people in India and Bangladesh. <br /><br />On a 1,000-mile journey from the world’s greatest water source in the Himalayas, down rivers and then by train through Nepal, India and Bangladesh to the Bay of Bengal, we saw evidence of profound changes in weather patterns right across south Asia. The starting point was Jomsom, a small town in the Kali Gandaki valley, 2,300 metres high and at the heart of the Annapurna range. This remote town, which saw its first ever car last year, has experienced no snowfall this winter. The temperature soared way above normal to 27C, and only fell to 13C, against a usual -4C, while the snowline has risen above 5,000 metres. The Gandaki river, fed by 1,200 glaciers, flows to the Ganges and on to Bangladesh. <br /><br />Nepal’s story<br />It’s the same story even in the Everest valley region, 400 miles to the east of Jomsom, where the snowfall is becoming increasingly unpredictable. Two hundred miles away in Nepal’s capital, Kathmandu, Simon Lucas, a climate change officer at the UK Department for International Development, confirmed that river flows in winter have seriously declined. “The trends are clearer in Nepal than in other countries,” he said. “People cannot plant their crops in the spring because the winter snows are not so heavy. They have always relied on snow and glacier melt.”<br />Britain earmarked £50m for Nepal to adapt to climate change, mainly through investing in its forests, but climate scientists say it faces ever more erratic, intense and unpredictable rainfall. We found the evidence for that when we headed south towards Nepal’s border with Bihar in India. Here the problem is not too little water but far too much; last year, following torrential monsoon rains, Nepal’s greatest river, the Khosi, broke though two kilometres of embankment and flooded hundreds of square kilometres of farmland. Nearly 1,500 people died and three million people were displaced. Fifty thousand people in Nepal and many more in India lost their homes, and the river changed its course by more than 150km. <br /><br />From severe flood to deep drought<br />We crossed the Indian border and went straight from severe flood to deep drought. Bihar, one of India’s poorest states, is experiencing one of its worst droughts in a generation. This year it has had only 15-30 per cent of its usual rains. “Climate change is definitely happening,” said Vyas Ji, principal secretary in the department of disaster management in Patna. We headed to Kolkata, one of India’s great cities, which was warned again by scientists that it was acutely vulnerable to sea level rises. <br /><br />“Climate change is not the future. It is now. Tens of thousands of Indians are already in a critical situation,” said Sugata Hazra, director of Jadavpur University's school of oceanography in Kolkata. His researchers have recorded sea levels in the Bay of Bengal rising far faster than the global average, and more cyclones hammering the coast. The result is the inundation of islands from higher tides and surges.<br /><br />To the Bangladeshi border<br />From Kolkata, we headed to the Bangladeshi border. Bangladesh is by far the most densely populated large country in the world and, being entirely on a low-lying delta, it is one of the most vulnerable. It stands to lose 20 per cent of its land to sea level rise in the next 80 years and is already experiencing more frequent and more intense cyclones. In the last seven years, four of the most powerful storms ever recorded have slammed its coasts.<br /><br />Our south Asian climate odyssey from source to sea ended south of Chittagong, on the Bay of Bengal. <br /><br />There, where the waters of the Kali Gandaki, the Ganges and Nepal’s many other rivers reach the ocean, communities are experiencing higher tides and more flooding, as well as the loss of farmland and fishing.<br /><br />“The sea water now comes right into our houses. We would all like to move, but there is nowhere to go,” said Geeta Das, a teacher in Bolihut village, near Chittagong. Her home has been partly washed away and her bed is now just a foot from where the waters reached a few weeks ago. "We panic when it is cloudy and it is about to rain. We fear we will lose our children."</p>