Few who watch the documentary Red Ape: Saving the Orangutan tonight on BBC2 could fail to feel some sense of responsibility for the desperate situation faced by Indonesia’s orangutans. These extraordinary creatures are our closest relatives, sharing 97% of our DNA. Their similarity to us is astonishing. They are intelligent, inquisitive, smile and show empathy. They even laugh when tickled, like us, when most other animals have evolved to be ticklish only in an itchy, irritating sort of way as a protective reflex. Encountering orangutans in the wild is like nothing else I’ve experienced.

They once thrived in Indonesia’s lush, green rainforests but over the last 50 years they have been forced from their home and killed. In the last 16 years alone, 100,000 Bornean orangutans have been lost. All three species – Bornean, Sumatran and the Tapanuli, a species discovered only last year – are now on the critically endangered list. The reason? It started in the 1960s as forests were logged for timber, but now it’s palm oil.

Global demand for palm oil has increased six-fold since 1990. It’s in half of all packaged products on supermarket shelves and to avoid it completely would be incredibly tricky. Although palm oil in food can no longer be described simply as vegetable oil and must be clearly labelled (thanks to an EU directive in 2014), there is no such law for products such as soap, shampoo and other cosmetics. The supermarket Iceland’s decision to ditch palm oil from all of its own-brand products was, it says, a response to the palm oil industry’s catastrophic failure to halt deforestation and deal with the problem.

Even the Roundtable on Sustainable Palm Oil (RSPO) – the industry body charged with ensuring registered companies trade only in oil that has not come from deforestation – is failing spectacularly. Just over a week ago, Greenpeace exposed massive rainforest destruction in Papua allegedly caused by palm oil companies that are subsidiaries of a current RSPO member. Buying from them were big multinationals including Unilever, Nestlé, Pepsico and Mars. The companies concerned have responded by saying they are taking Greenpeace’s claims seriously and taking appropriate action. But if Greenpeace’s assertions are correct, no company can claim the palm oil it uses is 100% “sustainable”.

Red Ape reveals the truly remarkable work that International Animal Rescue workers are doing on the ground to save these animals. At this crucial stage in their existence, every life saved is vital to their survival. But if we want to save orangutans in the long term, as John Sauven, Greenpeace UK’s executive director, says in the programme, we must save their home – the rainforest. You can sign Greenpeace UK’s petition to support this mission.

Orangutans spend 95% of their lives in the trees, but right now, Indonesia’s forests are disappearing at the rate of one football pitch every 25 seconds. In the absence of industry reform, multinationals such as those mentioned above must take responsibility. In fact, back in 2010 they actually promised to take responsibility. Then, members of the Consumer Goods Forum pledged that by 2020 they would no longer buy palm oil from any company that decreased the net amount of rainforest. But have they done anything about it? Not much, it seems. In fact, in January this year, when Greenpeace asked 16 companies to publish which palm oil traders they were buying from, many refused – although not those listed above.

With rainforest clearance continuing and the Indonesian government boasting a projected increase in palm oil production from 36.5m tonnes in 2017 to over 42m tonnes by 2020, the situation really is dire. And it’s not just orangutans that are threatened. More than 69% of Sumatran elephant habitat has been destroyed within one generation, and there are fewer than 100 Sumatran rhinos left in the wild. People are part of this conflict too. Land grabbing and exploitation of workers, including the use of child labour, is endemic. And decades of deforestation for palm oil have created conditions ideal for furious forest and peatland fires. These fires, often deliberately started by companies clearing the land, threaten the health of people across southeast Asia and drive climate change.

Indeed, if nothing is done, eventually we will all pay the price, since land-use change, mainly from tropical deforestation, accounts for 12% of global carbon emissions. Keeping these forests intact really is vital for all life on Earth. There can be no more delaying until the next decade. 2020 is less than two years away and the burden of responsibility lies firmly with the multinationals. Palm oil can be produced without destroying rainforests but only if big companies support it. I won’t let them forget their zero-deforestation promise. Will you?

• Chris Packham is a naturalist, nature photographer and author