How Did the Amazon Rainforest Fires Start?

Wildfires are currently burning across large tracts of the Amazon rainforest in Brazil, amid international outcry over inaction on the part of President Jair Bolsonaro's administration.

Brazil has experienced a record number of wildfires this year, more than half of which occurred in the Amazon region. That's according to data collected by the country's National Institute for Space Research (INPE).

The figures show an 83 percent increase in comparison to the same period in 2018, representing the highest number of blazes since the agency began collecting such data in 2013, Reuters reported.

In fact, INPE says it has identified more than 72,000 fires in Brazil between January and August this year, comfortably more than the roughly 40,000 recorded in the entirety of 2018. Many of the recent fires in the Amazon region have been centered on the Brazilian states of Rondônia, Pará, Amazonas and Mato Grosso, which saw a 39 percent increase over 2018 as of August 2.

So what exactly is causing these fires?

According to NASA, the Amazon rainforest has been relatively fire-resistant throughout its history due to its moist and humid conditions. But an increase in the frequency and intensity of droughts—a phenomenon that's linked to anthropogenic climate change—in combination with human activities in the forest has led to a spike in the number of fires.

While natural wildfires do sometimes occur in the Amazon during the dry season—which runs roughly between August and November—these tend to be relatively low in frequency and intensity, with flames that only reach a few inches in height, Mongabay reported.

However, experts are warning the recent spike in wildfires is likely the result of human activities.

"This is without any question one of only two times that there have been fires like this [in the Amazon,]" ecologist Thomas Lovejoy told National Geographic. "There's no question that it's a consequence of the recent uptick in deforestation."

Recently released INPE data has shown that Amazon deforestation rates have risen to the point where around three soccer fields of tree cover are being lost every minute, The Guardian reported. In fact, the figures show that in July this year, deforestation had increased by nearly 300 percent in comparison to the same month in 2018.

Unlike previous years in which Amazon wildfires have been linked to unusually low rainfall—experts say that conditions this year have been relatively moist.

"There is nothing abnormal about the climate this year or the rainfall in the Amazon region, which is just a little below average," Alberto Setzer from INPE told Reuters. "The dry season creates the favorable conditions for the use and spread of fire, but starting a fire is the work of humans, either deliberately or by accident."

Fire is commonly used in the Amazon as a technique to clear land for cattle ranches, soy plantations or other uses, although the practice is not always legal.

Brazil Amazon fire
A fire burns trees next to grazing land in the Amazon basin on November 22, 2014 in Ze Doca, Brazil. Mario Tama/Getty Images