Why the Amazon rainforest fires are such a challenge, from Nine's reporter in Brazil

The Amazon rainforest is huge, complex, and on fire.

The reasons for the blazes are also varied, and sadly this is tackling the flames so much harder.

For a week now, the world has watched as tens of thousands of fires have sent smoke from where we are in Porto Velho in the northwest all the way to Sao Paulo and the Southern Atlantic.

By now you've probably heard the statistic – 20 per cent of the planet's oxygen is produced here.

On face value, that makes this crisis a global crisis. But on the ground in Brazil, proud locals see this as a problem for Brazilians.

Global leaders meeting 9000 kilometres away for the G7 summit in France have agreed to offer more than $AUD29million to help.

Actor Leonardo DiCaprio's environmental group have chipped in $AUD7million more.

In Brazil the money is welcome, the intervention is not.

President Jair Bolsonaro tweeted that global leaders were treating Brazil "as if we were a colony or no man's land".

And still the Amazon burns.

Bolsonaro has made 40,000 troops available to help fight the fires.

We travelled to one of their makeshift bases at a logging station inside the rainforest.

There, a single armed guard stood watch while dozens of soldiers played pool on an old table in the outdoor covered area.

A map and troop rotation details were written on a white board, and the whole operation was being run out of a tent that has been set up with computers.

The commander told us through a translator the task is difficult because of nearby farmland.

Farmland here is private property and Bolsonaro's new laws have eliminated many of the rules in regards to land clearing.

The US-China trade war is escalating demand for Brazilian beef, soy beans and fruit.

It's a profitable business in an area that could use the profits.

But livestock and crops need land, so many farmers have used the dry season to set fire to their paddocks, clearing the way for agriculture.

On the way to the base we passed skinny cows picking at grass on properties that border rainforests.

When two monkeys scampered in front of the car, it was a surprise change from the dozens of chickens and pigs we'd already seen.

Here, locals don't care for the talk from France - an agricultural powerhouse - about global environmental responsibilities.

But clearing land has an undisputed environmental impact around here as well.

The rainforest is reliant on consistency of cover to maintain temperatures and water levels; remove too many trees and it impacts the rest.

Brazil's space agency says more than 85,000 fires have started this year.

The president points the finger at different groups, including non-government organizations and charities.

Many of these groups have questionable records with corruption and Bolsonaro says by lighting fires they guarantee more money and more donations flow into the country.

It would explain the increased interest in the fires this year.

While the number of individual fires is up more than 80% on last year, 2019 still sits well behind some previous years.

Australians will know the regenerative impact fire can have on the bush, but the rainforest is less hardy.

When we were about to leave the camp, a helicopter returned from surveillance; they'd spotted someone lighting fires deep in the equivalent of a national park.

It was a reminder that this battle has many fronts that are constantly evolving, and until the heavy rains fall in November victory will be difficult.

It is a challenge as diverse as the incredible landscape, and there's no obvious solution.

Political and economic posturing means plenty of oxygen is being wasted while the Amazon burns.

And if the Amazon burns, there'll be far less oxygen to go around.