As Cristiane Mazzetti flew over the Brazilian Amazon this month surveying wildfire damage, she couldn't help but feel frustrated.

Mazzetti is a forest campaigner for Greenpeace in Brazil. For years, the environmental group has been trying to curb the deforestation and climate change that makes the country so susceptible to wildfires.

And yet this summer, fires are breaking records in the country, ripping through the Amazon rainforest and Cerrado savanna, destroying huge swaths of biodiverse wetlands, razing sugarcane plantations, and even bringing thick smoke and smog to the country's usually unscathed capital city Brasilia.

"We've been, for so long, working to change things, and it's hard. It makes me sad — makes me think about the people who live near those areas that are being destroyed, the people who live in the cities nearby and get sick, the people that already suffer with respiratory diseases and they get very infected," Mazzetti told As It Happens host Nil Köksal.

"It feels frustrating. But at the same time, we cannot give up."

'People are setting fires'

Brazilian Environment Minister Marina Silva says the country is "at war" with fire. 

Fire alerts so far this month total almost 3,500 in southeastern São Paulo state, the most registered in any month since data collection began in 1998. Hot spots recorded in the Amazon this summer are up 98 per cent over last year, according to Greenpeace.

Two employees working at an industrial plant in São Paulo died Friday while trying to fight back a fire. In the Amazon, a federal brigade firefighter also died Monday while working in the Capoto Jarina Indigenous Territory.

Winds are carrying smoke to Brasilia, where the skies are so dark that drivers need headlights to navigate traffic in daylight hours, Mazzetti said. Smog has caused 48 cities in the state to declare a red alert, forcing schools and events to shutdown.

The government says these fires are far from natural.

"No fires caused by lightning were detected. This means that people are setting fires in the Amazon, the Pantanal, and especially in the state of São Paulo," President Luiz Inacio Lula da Silva said Sunday.

The day after the president made those comments, São Paulo's governor announced four men had been arrested on suspicion of setting fires that destroyed thousands of hectares of sugarcane plantations in the north.

State Agriculture Secretary Guilherme Piai said Tuesday that some of the arrested men told police they are linked to one of the country's largest criminal gangs, the Primeiro Comando da Capital.

WATCH | Fires raze farmland in Brazil: 

Brazil fires devour farmland over the weekend

Drone footage from São Paulo state on Aug. 24 shows fields consumed in flames and massive plumes of smoke lingering overhead

Mazzetti says the wildfires that burn every year in the rainforest are also, by and large, manmade.

Greenpeace and other environmental experts say the key driver behind Brazil's wildfires is deforestation — specifically, people and companies who deliberately, and often illegally, set fires in order to clear the land of vegetation so it can be repurposed for other uses, like agriculture.

Since the da Silva government took power last year, deforestation in the Amazon decreased 45.7 per cent between August 2023 and July 2024, Greenpeace said, citing data from the Brazilian National Institute for Space Research (BNISR).

By contrast, deforestation had surged to record levels under former president Jair Bolsonaro, who advocated clearing protected forests to make way for farming and mining.

But Greenpeace said 666 square kilometres of deforestation were recorded July of this year, a 33.2 per cent increase from the same time last year. That, it said, was accompanied by a surge in hot spots. 

To stop this from happening, Mazzetti says the government needs to enact stiffer penalties for environmental crimes, and enforce those laws more stringently. 

"People who commit those kind of crimes, they just bet that they will get away with it without having a proper punishment," she said.

Deforestation is a major driver of climate change in Brazil — and climate change, in turn, exacerbates the fires, Mazzetti said

Despite this vicious cycle, she hasn't given up hope.

"There is still time," she said. "We keep on fighting for making sure that actions and policies are put in place for dealing with the scenario, for dealing with adaptation to climate change, and for mitigating climate change to deal with deforestation.

"We cannot just give up."

With files from Reuters and The Associated Press. Interview with Cristiane Mazzetti produced by Owen Leitch