Brazil's Amazon wilderness at risk from organised crime
We are flying low in helicopter formation over the Brazilian Amazon with agents from Ibama - the state-funded institute responsible for environmental protection.
No country has done more than Brazil in recent years to tackle the previously rampant levels of deforestation but there is a good reason the agents have their guns drawn - we have seen statistics which show that rates of Amazon destruction are again on the rise.
There are big profits to be made from illegal logging and the fraudulent clearing of rainforest for valuable cash crops and these helicopter patrols are often shot at.
Trying to locate illegal logging operations in the midst of this dense jungle from the air is like looking for the proverbial needle in a haystack.
Destroyed on the spot
There are probably thousands of small illegal logging camps across the Amazon. Men armed with machetes and chainsaws, cutting down valuable Brazilian hardwoods are the foot soldiers in a highly profitable and dangerous trade.
On the ground, the Ibama agents show little sympathy to the loggers.
Those that are caught risk arrest, their camps are set alight and their machinery, including expensive tractors and other equipment, are destroyed on the spot.
All of this might appear harsh but, says Maria Luisa de Sousa, the Ibama official who has been co-ordinating this month-long operation in northern and eastern Mato Grosso, the fight to save the Amazon is increasingly a fight against organised crime.
"You can compare it to the struggle against drugs trafficking. The crime and the criminals keep on adapting."
As we wait for our helicopter to be refuelled before heading out on another mission she adds: "They're getting even more sophisticated, using even bigger tools to deforest, which makes it even more dangerous for us.".
We fly on, over virgin jungle, but also over immense fields of soya and corn, cash crops that have earned valuable export profits for Brazil in recent decades and also help to feed the growing population in the south of the country.
Some of the most recent deforestation sometimes seems blatant and egregious. Down below we spot two huge tractors - the "new beasts" of the jungle.
They are involved in one of the most destructive forms of deforestation in the Amazon.
In this case, several acres of trees have been felled in a couple of days or weeks. Dragging a huge, steel chain between them, the tractors have felled everything in their path.
New monthly figures show that deforestation rates in some parts of Brazil have almost doubled compared to last year.
Those statistics also show that increasing amounts of wood are illegally taken from protected indigenous reserves.
Three hours' drive from the town of Aripuana, I spent two days with members of the Cinta Larga tribe.
They may wear Western-style clothes and live in wooden shelters, rather than grass huts, but they mainly live in and off the forest.
This is a reserve being increasingly invaded by illegal loggers - unscrupulous and sometimes threatening gangs who cut down trees by day and spirit away truckloads of wood by night.
"The loggers come in here for the valuable hardwoods that have already been lost elsewhere," says Amadeus.
"That's why the pressure on our land and all the indigenous lands around here is so strong."
In some areas, its thought that as much as 80% of the timber felled is done so illegally - from state-owned or indigenous land.
Back in Aripuana, there seems to be as many timber mills as there are coffee shops in Rome.
It is in the sawmills that illegal or "dirty" wood with false certification gets mixed up with the legitimate industry.
"There's no way to tell which timber is legal and which is illegal after the chain is contaminated," says Greenpeace researcher Marina Lacorte.
"We're asking international companies and importers to stop buying timber from Brazil because there's no guarantee that official documents can guarantee the legal origin," she adds.
Such a move would surely be harsh on those legal timber companies who have nothing to hide about their operations.
SM Wood & Laminates only deals in certified timber and in its yard huge, decades-old logs await cutting up for export.
More than 50 people work at the plant in a region where 20 million Brazilians now live.
Manager Vanderlei Nunes is frank and honest in his view that only by placing a monetary value on the forest, allowing managed exploitation of the Amazon - including indigenous areas - can the rainforest survive.
"I think that people in the south of Brazil and in Europe and the US think the forest is untouchable, but they forget that there are people living and working here," says Mr Nunes, who like many of those who now call the Amazon home, initially came here in search of work from other parts of Brazil.
"So until we find a formula for them to live from the forest - get an income from it and give it a value - then the Amazon problem won't be resolved."
Last week in a highly publicised trip to Washington, Brazil's President Dilma Rousseff expressed her "deep concern" for the climate and in a joint press conference with US President Barack Obama, she made numerous pledges about the environment - promising among other things to stop all illegal deforestation.
But many environmentalists are sceptical about her ability to deliver on her promises.
Under tighter economic constraints her government has repeatedly cut environmental budgets, while the emphasis has often lent towards the right of Brazil to develop and exploit its resources over the need to protect biodiversity.
As long as that remains the case and if President Rousseff fails to match the rhetoric in Washington with the appropriate resources, the future of this unique wilderness remains in jeopardy.