Orang-utans are critically endangered (they only survive on Borneo and Sumatra) due to their rainforest habitat being systematically destroyed. At the current rate of destruction, there will be none left in the wild in 10 years.

Indonesia has already lost 75% of its rainforest and the orang-utan is just one of 140 species of mammal that is threatened with extinction here - let alone other animals, insects and plants.

The rainforest here is second only to Amazonia in terms of size and biodiversity, and climatologists say that the rainforest is the lungs of the Earth - one of our last defences against global warming, absorbing millions of tons of carbon emissions every year.

Not to mention the unexplored/unexploited plants - more species of animals and plants live in the rainforest than in the rest of the world combined.

The main reason for destroying the rainforest is to take out the timber. All you have to do is cut all the trees down and float them down the river - nice money. Unfortunately, the land will never recover. If you leave it alone, the thin topsoil gets washed away down the rivers and what you leave is desert - this is the Equator.

Once you have razed the forest, you can, however, grow palm oil, also profitable business. And if you can't get permission from the Indonesian government to clear the forest to grow the stuff... well, in 1997/8, vast fires in which the palm oil companies were heavily implicated, killed 20,000 orang-utans (one third of the population at the time), in 2002 these fires accounted for 40% of the world's carbon emissions for the year.

We have been battered by statistics like this for many years. But when you are surrounded by this stunning and serene habitat, getting up close and personal with a species that shares 95% of our genes, then what we are doing to the habitat and to the orang-utans just makes you weep.

What on earth is there in that different, flawed 5% of our genes that makes us think we can do this and get away with it? More astonishing, what is there in that 5% of our genes that allows us to carry on doing this when we know we won't get away with it?

We knew that the orang-utans would be a highlight of our trip, but neither of us knew quite how much it would affect us.

To our grandchildren, born and as yet unborn, we apologise on behalf of our generation and previous generations that unless the human race has a rapid and massive change of behaviour, then by the time you are old enough to experience what we have this experienced this week, it will be gone.

Check out..

www.orangutan.org