GETTY - NC Up to 20,000 orangutans are at risk of being burned out of their homes

The environmental catastrophe that is unfolding across Indonesian Borneo is threatening to engulf precious sanctuaries where a third of endangered great ape's entire population hangs on for survival. For two months, uncontrolled fires have been raging across the Borneo landscape, spewing up thick black clouds of smoke that have caused respiratory infections in 500,000 people. The financial cost for Indonesia is also immense, with the fires costing the economy as much as £30billion. Conservationists are warning the fires' impacts have taken a sinister twist by setting light to huge swathes of virgin peat swamp forest, a precious tropical wilderness where endangered clouded leopards and orangutans keep one step from extinction. For how long. "The situation is dire and deteriorating by the day," the Orangutan Tropical Peatland Project (OuTrop) warned today as it revealed the increasing fire threats. OuTrop reports fires are currently destroying orangutan strongholds at Tanjung Puting National Park, which is home to 6,000 orangutans, the Katingan Forest, where there are still 3,000 orangutans, and at the Mawas Reserve, home to an estimated 3,500 of the wild apes.

The situation is dire and deteriorating by the day Orangutan Tropical Peatland Project

But, says OuTrop, it is the Sabangau Forest, with the world's largest population of nearly 7,000 wild orangutans, which is facing the greatest threat. OuTrop's Founder and Director of Conservation, Simon Husson, appealed today: "People are choking in the smoke and one of the world's last, great rainforests is burning down. The only way to tackle this is with huge manpower on the ground, supported by intensive and sustained aerial water-bombing. "Mobilising these resources requires raising international awareness of the catastrophe unfolding in Sabangau. Eventually the rains will come and only then we will see how bad the damage really is. But simply waiting for the rains is not a solution. We need the eyes of the world on Indonesia, we need more support and we need it now."

GETTY Uncontrolled fires in have been raging across Borneo for two months

Looking down from space, NASA satellites have detected 358 fire hotspots devouring the forests and burning both above and below ground, bringing down huge trees as theirs roots are incinerated. Forest clearance and draining the peat swamps as well as the drought effect of a strong El Niño weather system are allowing the fires to burn with greater intensity and spread from farmland, plantations and scrubland into the precious wilderness areas. OuTrop's managing director Dr Mark Harrison, said: "In their undisturbed, flooded state, peatland forests are naturally fire-resistant.. But decades of poor peatland management practices, including extensive forest clearance and canal construction, has drained the peat, putting the whole region at high fire risk when the inevitable droughts occur. "We've have been part of a huge effort since the mid 1990s, working together with hundreds of people from many local and international organisations, to conserve this special forest, stop illegal logging, prevent conversion into oil palm and protect it for future generations.

GETTY A worker tends to the orangutans at a rehabilitation centre