Peru's glaciers are melting. High in the Andes, freak hailstorms and cold snaps are freezing llamas to death. In the north of Kenya, unprecedented droughts have driven herdsmen into deadly battles for the few water holes. In the mountains of Tajikistan, near the border with Afghan-istan, flooding and landslides are washing away the crops.
Across the developing world, man-made climate change is an indisputable reality and it is already hitting hardest against the poorest nations.
Historically, the warming of the atmosphere has been the product of CO2 emissions from industrialised nations, but as scientists now agree global warming is upon us, the countries that have polluted the least are already the most hard-hit.
In addition to immediate steps to reduce emissions, £50bn is needed annually to help developing countries meet the immense costs of adapting to a climate change they have done least to cause, according to a report by Oxfam. "Developing countries cannot and should not be expected to foot the bill for rich countries' emissions," said Kate Raworth, Oxfam senior researcher and report author.
The latest opportunity for the developed world to take action on the greenhouse-gas emissions which are driving the changing climate comes in a fortnight in Germany at a meeting of the G8 group of the richest nations. Germany, backed by Britain and Japan, wants a pledge from members to cut their CO2 emissions in half by the middle of the century, and a commitment to limit global warming to 2C.
But these efforts look like hitting a wall in the shape of entrenched US opposition. A leaked draft of a communique ahead of the G8 meeting, from 6-8 June in Heiligendamm on Germany's Baltic coast, appeared to show that the US was set to reject any real progress on climate change.
Unattributed comments on a draft summit communique, which Greenpeace said were written by US officials and leaked to them through a third party, appeared to show there was no shift in the Bush administration's intransigence on global warming.
"The US still has serious, fundamental concerns about this draft statement," the notes read. "The treatment of climate change runs counter to our overall position and crosses multiple 'red lines' in terms of what we simply cannot agree to."
The US, with under 5 percent of the world's population, pours out nearly a quarter of global emissions. It is followedby China, then Indonesia and Brazil - whose emissions are driven by deforestation - then Russia and India. The US has refused to ratify the international agreement on reductions, the Kyoto protocol, saying it could not endanger its own economy.
That agreement, calling for more modest cut, expires in 2012, and the German Chancellor, Angela Merkel, had been determined to use the G8 as a first step towards negotiating a new "son of Kyoto" agreement at the UN climate summit in Bali this year.
Tony Blair, who will leave office next month, has been desperate to get a breakthrough on climate change from the White House to seal his legacy but so far he has received nothing but rhetorical concessions from his closest ally. America has tended to cite China and India's absence from Kyoto as a reason for staying outside international agreements, while Delhi and Beijing have pointed to the West's historical responsibility for emissions as a reason to reject cuts. But sources close to negotiations say this has been a convenient stand-off for both sides.
A dramatic shift by Japan, which joined the EU countries in calling for a 50 percent cut in emissions by 2050, appeared to breathe new life into the negotiations but diplomats have since been dampening expectations.
While the first two points of the five-point summit communiqué - the need for a commitment to limiting average temperature rises and the establishment of a global carbon trading scheme - are the most problematic, there may be scope for progress on the remaining points. Those include combating deforestation, the development of new green technologies and adaptation funds for developing nations.
Oxfam has said the estimate of £50bn every year to meet poorer nations' costs in fighting climate change is conservative. So far, G8 nations have pledged a total of £182m in adaptation aid to developing nations, less than the money to upgrade the Underground's cooling systems.
The report, Adapting to Climate Change, ranks countries based on their responsibility for carbon emissions from 1992 up to 2003, and on their capability to pay, based on their position in the UN's Human Development Index: the US, responsible for meeting nearly 44 per cent of developing country adaptation costs; Japan, nearly 13 per cent; Germany, more than 7 per cent and the UK, more than 5 per cent.
"Justice demands rich countries pay for the harm already being caused to those who are least responsible for the problem," said Ms Raworth. "This is not about aid; it is about the world's biggest and richest polluters covering the costs forced on those who are most vulnerable, an entirely separate and added responsibility."
Pelosi pushes Bush to act before G8 summit
The arrival in Berlin of a bipartisan delegation from the House of Representatives, headed by the Speaker, Nancy Pelosi, is proof of how the Democratic-controlled Congress, working with US states and business leaders, will try to prod a reluctant Bush administration to take stronger steps to tackle climate change. Ms Pelosi flies to London today on her first visit since her election as Speaker. The White House has already said it will have nothing to do with binding targets for reducing carbon emissions at the G8 summit in Germany.
But it is being bypassed, first by more than 12 states, led by California, which are introducing tighter regulations of their own, then by major corporations, including energy companies. In the House, Ms Pelosi has set up a Committee on Energy Independence and Global Warming, to offer advice. The Foreign Affairs Committee has backed a bill ordering the Bush administration to send diplomats to international meetings on climate change "to secure binding commitments for reform".
Already on the fringes of inhabitable environments, the Turkana people of northern Kenya have found themselves among 11 million people in east Africa affected by biblical-scale droughts. Many people have been displaced and huge numbers of cattle and camels, vital for survival, have died.
Anna Nangolol says: "My name means 'Born at a river', but the river has been dry since April four years ago. Past droughts in Turkana have been short. The rains would return. But this drought never seems to finish."
The Turkana give names to the increasingly frequent droughts they are facing. They called the 2005-06 drought Atiaktiak ng'awiyei, or "the one that divided homes" because so many families split up to survive, migrating in all directions to the borders, towns and relief camps.
Turkana people herd animals for a living. They move cattle, sheep and goats to follow meagre grazing fed by scarce rains. But droughts seem to be becoming far longer. A way of life that has survived for hundreds of years is under serious threat. Communities fear for their future.
Nature can be extreme and threatening to established order in the Sandia river basin of southern Peru, but many of the threats have been increased by climate change, including an intensifying El Niño cycle and ongoing Andean glacier melt.
During the rainy season, between November and February, people are vulnerable to flash floods. The surrounding mountains pose further dangers of rock falls and landslides. Sabina Soncco lives in the town of Sandia. She says: "When the water is high you can't even sleep. It's very frightening, especially when there's a lot of rain, like in February. I just want to run away. I just think, 'Where can I go?' But I don't, because my children and all my things are here.
"The last time it happened was last year. All the water came down with papaya trees and other things. After about an hour, the water went down; it always goes down, but it's very frightening when it's so high.
"Every year it varies. It depends on the amount of rain. Sometimes there's a lot and sometimes there's not so much. We just have to see what happens. I stay here because ... well, where else can I go? If I could, I would go somewhere else."
Laila Begum lives on a silt bank in Bangladesh's giant Jamuna river. The massive river delta is home to millions of people caught between the melting glaciers of the Himalayas and the warming, rising seas. She moved here in 1998 when she lost her first home in a flood. The silt bank keeps eroding so her family is forced to move their home around.
"Twenty or 30 years ago we could understand from the water temperature and the wind direction if the flood was going to come," says Ms Begum. "Before, it was mostly monsoon flooding in July or August, but now the rains continue into October. That causes problems because it's when we should be planting our crops. Oxfam gave us mobile phones so we can call for help."
Howard Fernández, is a Miskito, farming in San Andrés de Bocay community, Nicaragua. The Miskitos, indigenous people of central America, have been living and farming to natural rhythms for centuries.
But now something is going wrong. In the past few years, they say they have no longer been able to predict the seasons so they don't know when to plant. Their traditional signals of rain, such as eagles and lightning, have disappeared. "The summer now is winter. April used to be summer, but it rained all month. Now, in May [winter] it doesn't rain. We listen to the thunder, we see the lightning that should let us know the rain is coming, but it is not. Because of this climate change, we are suffering the decrease of our farm's production."
Tajikistan is a mountainous country which experienced significant retreat in its glaciers over the 20th century. Global warming is forecast to speed this, initially increasing the volume of water coming off the mountains in some places, but over the longer term causing a catastrophic decrease in water availability.
Mirzokhonova Munavara is an agronomist in the drought-hit region of Khatlon, near the border with Afghanistan. He says: "There has been a change in climate in the past 15 years. It gets extremely hot, then extremely cold. People are struggling here because we do not have the rain at times to water our land. We cannot leave this village because we have nowhere to go and no money. We need to learn how to adapt to grow food."