It was on Sunday afternoon that the alarm was raised and a search party sent out. Dom Phillips and Bruno Araujo Pereira had set off for the town of Atalaia do Norte at 6am - a journey through the Amazonian network of rivers that should have taken three hours at most. Their boat had plenty of fuel and a satellite phone. But after eight hours, there was no sign of them. Everyone feared the worst.

Phillips is a British journalist who has lived in Brazil for more than 15 years. He is an expert on environmental matters who has written for many media outlets including The Guardian. Bruno Araujo Pereira is a former government official with the job of protecting Brazil's uncontacted tribes from the loggers and miners who are invading their lands.

The two have been carrying out research in the Javari region of Amazonas stateA huge area of rainforests and rivers close to the border with Peru.. It is home to over 20 indigenous groups.

Tensions in the region have grown in recent years, particularly since the murder of another indigenous protection official in 2019. Conservationists lay much of the blame on President BolsonaroA former army officer, he was elected in 2019. He has been nicknamed "The Trump of the tropics"., who has weakened laws protecting the rainforest and dismissed evidence of increasing damage to it as lies. He has also sacked many top environmental officials21 out of 27 state superintendents were dismissed..

According to an indigenous leader, Beto Marubo, "Under the Bolsonaro government, the pressure has increased even more because the invaders felt empowered and became more aggressive." Criminal gangs, he says, are plundering the jungle with impunitySafety from punishment. It derives from a Latin word for penalty..

The gangs cut down the biggest trees in officially protected areas to sell as timber. They then burn the remaining vegetation so that the land can be turned over for cropsPlants that are grown on a large scale by farmers, such as vegetables, fruits and wheat.  or grazing for cattle. Over the past 40 years, around 170,000 square miles have been cleared - an area twice the size of Britain.

Experts warn that the rainforest is being pushed towards a tipping point beyond which it will never recover. Meanwhile, the people who traditionally inhabit it are being forced into an ever-smaller area.

The police do not have the resources to cover such a large region, so the indigenous people and environmental groups have set up networks to deter and report on the criminals. They have paid a heavy price: according to Human Rights WatchA charity based in New York. It was awarded the 1997 Nobel peace prize for its part in the International Campaign to Ban Landmines., over 300 activists have been killed in the past decade. Officials trying to enforce the law have been confronted by heavily armed mobs.

Corruption is a further problem, with some officials in the pay of the criminals. They supply false documents to allow the takeover of land and to pass off stolen trees as legally felled ones.

On Monday night Sian Phillips, the missing journalist's sister, made an appeal for help. "We knew it was a dangerous place, but Dom really believed it's possible to safeguard the nature and the livelihood of the indigenous people... We love our brother and want him and his Brazilian guide found... Every minute counts."

Yes: The majority of Brazilians believe that it should be protected, and Bolsonaro is more than likely to be defeated in October's presidential elections: the latest poll puts his support at just 27%.

No: It is so enormous that it can never be policed effectively. There is a huge amount of money to be made from exploiting it, and the criminal gangs are willing to murder whoever stands in their way.

Or... Saving it is hugely important, but not enough on its own to combat the challenge of climate change. We all need to reduce our carbon footprint and put pressure on politicians like Bolsonaro.