textLungs of the world ... a child walks through deforested land in Yasuni National Park. Photo: Bloomberg
In their first hour in Yasuni's Amazonian forest, many people will see more creatures than they have in their lives, including some that have yet to be documented by science. To paddle up the Ayango creek, which leads from the traffic and pollution of the Napo River into the most biodiverse region on earth, is to encounter a wall of noise, bursts of colour and unimaginable combinations of life.

A tiger heron flaps lazily past our canoe, electric blue Morpho butterflies jolt the eye, spiders the size of a man's hand sit on branches and kingfishers flash past. On a mud bank, a lizard suns itself, while high up in the tree canopy, flying monkeys dart amid the grunting of hoatzin ''stinky turkeys''
 prehistoric survivors with claws that grow into wings that could have inspired the flying creatures of Avatar.

The thick vines, exotic plants, stunningly colourful birds and huge reptiles of the forests and water systems here far outstrip the wildest imaginings of any film director, but they are at risk from the worldwide trend of rising extinction rates and from local economic pressures to exploit underground oilfields.

textHome to a dizzying diversity of wildlife ... the squirrel monkey. Photo: Bloomberg
Yasuni, home to two of the world's remaining uncontacted tribes, has moved to the front line of a global battle between living systems and fossil fuels. Animal populations across the planet are 30 per cent smaller now than in 1970, according to the UN Environment Program. In tropical regions such as Ecuador the rate of decline is almost double that.

Just as the species must innovate to survive, Yasuni has inspired the planet's most creative and ambitious approach to biodiversity conservation, social development and climate change. Ecuador is the only country to have recognised the rights of nature in its constitution. After the discovery of a $7.2 billion oil reserve inside a pristine corner of the Yasuni National Park, the government has proposed leaving the fossil fuel in the ground if other countries will give them half that amount.

It has been hailed as an alternative to the ineffectual efforts of the United Nations to deal with climate change and biodiversity loss. The ITT Initiative, as the project is known, promises to the keep carbon in the ground in a 200,000-hectare corner of the park and, in the process, help to redistribute wealth from rich nations to the developing world and wildlife.

textNative to Ecuador ... Morpho butterflies. Photo: Melissa Fyfe
But, a little more than a year after it was launched, this bold project is as much at risk as the wildlife. Ecuador's President, Rafael Correa, said the results had been disappointing.

''This was a revolutionary idea. With a logic that I would call perfect: it implied a substantial change in the management of natural resources in the fight against climate change. It meant a transfer of resources from the richest countries - which are the biggest polluters - to poorer countries,'' he said.
 ''But what has happened since has been the opposite: because the US, UK and others can consume the assets generated by the Amazon jungle for free, they have committed absolutely nothing. The Yasuni ITT Initiative has raised a lot less than expected.''

With enthusiasm for the project cooling, oil companies are moving closer. A road is being built in a neighbouring oil exploration block inside the Yasuni park. Huge ecological wealth is at risk. One Yasuni hectare is home to a wider variety of trees, birds, reptiles and amphibians than in the US and Canada combined.

This ecological wealth is not just of interest to scientists, animal lovers and tourists. The UNEP estimates 40 per cent of the global economy is based on biological products and processes.
Biodiversity loss, it says, is becoming a greater concern for businesses than international terrorism. Pharmaceutical companies have based countless patents on results from the forest, where the chemical mix and match is immeasurably more dynamic than that of any science lab.

Recent research shows that biodiversity makes forests more resilient to drought. Other studies have shown they are less vulnerable to disease. This is crucial because the Amazon is also the world's greatest oxygen supplier and carbon sink, with more than half the world's above-ground carbon in its trees.

In international bodies, biodiversity loss was long treated as a poor cousin to climate change. But this is changing amid growing awareness that both are approaching dangerous tipping points as a result of human pressures. Earlier this year, a group of leading scientists warned that biodiversity loss could result in a ''global-scale state shift''.

''Much as the consensus statements by doctors led to public warnings that tobacco use is harmful to your health, this is a consensus statement by experts who agree that loss of earth's wild species will be harmful to the world's ecosystems and may harm society by reducing ecosystem services that are essential to human health and prosperity,'' said Professor Bradley Cardinale, an associate professor at the University of Michigan who led the study, published in Nature. ''We need to take biodiversity loss far more seriously - from individuals to international governing bodies - and take greater action to prevent further losses of species.''

But the trend is the opposite. World Wide Fund for Nature says it now takes 1.5 years for the earth to regenerate what we use in a year. The UN says almost one-fifth of vertebrate species are close to extinction, with amphibians most at risk. Each year, 52 vertebrate species move one category closer to extinction on the International Union for the Conservation of Nature ''red list'' of endangered species.

The ITT Initiative, which covers the Ishpingo, Tambococha and Tiputini oilfields that make up less than one-fifth of Yasuni National Park, reached its target of raising $100 million last year thanks to creative accounting and public support. Ivonne Baki, who is spearheading the fund-raising effort, says $200 million has now been raised, but more is needed. ''The cost of not doing something now will be far higher than the economic crisis. If we are serious about reducing emissions of carbon dioxide and doing something - which is all they talk about at international meetings - then this is the place giving oxygen to the world.''

Yet, there are many challenges. Money is not yet filtering through to local communities, where it is supposed to be used to improve social capital as well as protect biodiversity. There are concerns Correa may have lost some enthusiasm for the project.

''I want to meet the president because he has lost focus,'' said a village chief Giovanni Rivadeneira of the Kichwa indigenous group. ''We are concerned about education in our community. There was a promise from the president to work on that. He left a promise here and we are still waiting to hear about that.''

The governments of wealthy nations have given tepid backing. Some accuse Ecuador of environmental extortion. Most of the government-level ''donations'' so far are from Italy, which wrote off $51 million of its external debt as a contribution, and Germany, which is giving technical aid.
Much of the hesitation is due to concerns Ecuador may change its mind after accepting the money.

To offset this, Correa's government has worked with the UN to establish a trust fund for the initiative. It promises to return donations of more than $50,000 if the oil is exploited under a clause that says it can be used in the case of a national emergency. This is the plan B dreaded by conservationists.

Carlos Andres Vera, the director of a documentary about the Taromenane uncontacted tribe in the park, says 40 per cent of Yasuni is already being exploited by oil companies and the ITT area is being prepared for the same treatment. ''The oil companies have already carried out exploratory studies there. Local people say they are already building tracks so they can push ahead with plan B. They say they are trying to save Yasuni, but that's bullshit.''

To the alarm of many, PetroEcuador is pushing ahead with development of extraction on the edge of the ITT. Two recent visitors say a road is under construction on the edge of an area famous for jaguar sightings.

This follows a destructive pattern seen in other parts of the park and surrounding areas, where oil companies have drilled wells and - most destructively - built roads. This opens the way for migrants, loggers, farmers, hunters, invasive species and disease.

The risks are obvious flying into Coco, the gateway to Yasuni. Seventy years ago, the forest stretched hundreds of kilometres to the west, but all you can see are palm oil and other cash crops.

Freshwater ecosystems are deteriorating. A discarded oil drum bobbing in the Napo highlights the pollution from the oil barges and river traffic. Locals blame oil for the demise of balsa trees and water-skier insects from the banks of the trunk rivers.

''My father said there used to be a lot in the Napo River, but they have disappeared because of the gasoline from the oil companies and many boats,'' said Remi Grefa, a guide from the Kichwa indigenous group.

Conservationists still hope Ecuador and Yasuni can set a model for conservation. ''It is absolutely worth it,'' said the Indian ecological activist and philosopher Vandana Shiva.

''What is not worth it is the old way of fossil fuels as the central resources rather than living waters, living streams, living trees, living forests, living cultures. And a fossilised mindset that should have disappeared 100 years ago.''