How to stop fires in the Amazon and protect our climate

How to stop fires in the Amazon and protect our climate
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An alarming rise in human-caused fires in Brazil captured the world’s attention over the summer, shining a renewed spotlight on the need to conserve the Amazon rainforest. As scientists who’ve dedicated our careers to Amazon conservation, we would like the conversation to be about how to stop fires and protect our climate, but also how to fix a broken model of economic development that encourages short-sighted deforestation.  

In 2010, the smoke billowing from our experiment in the Amazon in which we conducted controlled burns of native standing forest baked our lungs and shocked our sense of what a hot dry year would mean for forest fires. 

The purpose of our burns was to help us better understand what happens when fires used for land management escape into the forest — a constant problem in the Amazon. But we ended up learning a lot more.


In normal years our fires were low and slow and never made it through the night. But 2010 was hot and dry and our fires were big, tall flames roared through the forest and the night was bright with fire. Later that year, when we looked at the satellite images we saw that huge fires had burned throughout the southern Amazon — more than 10 percent of the forests in the state of Mato Grosso, including in the indigenous reserves, had burned that year compared to almost none in a normal year. We learned that climate made a big difference — humans create sources of ignition in the Amazon every year. In a normal year, the natural wetness of the rainforest keeps them at bay, but in a drought year they very quickly get out of control and burn a lot of standing forest. 

Now in 2019 we see a shockingly large number of fires occurring in the Amazon. We are only half way through the fire season, but fire activity in 2019 has already surpassed the last four years in most Amazonian states. By Aug. 31, 30,901 fires had been registered, an increase of 51 percent relative to the average of the last three years for the same period and greater than 2016, which was an extreme drought year. The extent and number of fires of 2019 is reminiscent of dry years like 2010 or 2016.

There have been numerous statements, including from Brazilian government officials, that the fires were a result of or were being greatly exacerbated by drought. Except that 2019 is nothing like 2010. It is a relatively cool wet year. Normally the period between rainstorms ranges from 25 to 60 days. The maximum dry spell as of Aug. 31 of this year was less than 12 days in Amazonas State and only 29 days in Roraima State. 

So, if it isn’t dry this year, what is causing the extreme number of fires? Being able to definitively know the roles played by deforestation and drought is critical, it will define how we address our efforts at avoiding more fires in the near future. We find that deforestation is driving most of the fire activity in Amazonia in 2019, with climate conditions having very little effect.  

Our team at IPAM-Amazônia used existing satellite and ground-based data to identify where the current fires in Brazil occurred and correlated fires with recently deforested land and the longest number of days without rain. The top 10 Amazon municipalities in number of fire counts were also the ones deforesting the most. They were responsible for 37 percent of the fire counts and 43 percent of the accumulated deforestation this year.

This concentration of fires in municipalities experiencing high deforestation rates in a non-drought year tells us that the fires of 2019 were lit intentionally to clear recently deforested areas of the felled giants trees of the Amazon. We found that one-third of all fires occurred in undesignated public lands, which indicates active attempts to illegally grab public land. 

Finally, we estimate this year’s Brazilian Amazon fires have produced between 104 million and 141 million metric tons of carbon dioxide (CO2). That is equivalent to annual tailpipe carbon pollution from 22.6 million to 30.6 million cars, or the annual CO2 emissions from the entire state of North Carolina. 

In hindsight it is simple, there was a nearly 50 percent increase in clear-cutting trees in the Amazon this year, it should be no surprise that the number of fires also was extremely high. Looking back on those fires we lit in hot and dry 2010 we are also struck by how lucky we are that 2019 wasn’t a drought year. 

The fires, and the causes, make us think about the future of the Amazon. Even though this was not the worst fire season Brazilians have experienced in the last 15 years, it is the greatest amount of deforestation we have seen in a decade. This is what the destruction of a vast rainforest looks like: individual acts of relatively small deforestation with fires that escape into neighboring forests. A bit each year, with some years being worse than others and it soon adds up. We’ve already lost over 750,000km2 of the Amazon, nearly 20 percent, in the last four decades. We really can’t afford to lose more.

In addition to harboring immense biodiversity, this forest is a very important part of the global climate. It stores a great deal of carbon and is the source of much of the rainfall locally and thousands of miles away — which in turn supports agriculture, urban water supplies and a large fraction of Brazil’s economy. Thus, continued deforestation doesn’t just destroy a magnificent forest, it will likely lead to runaway climate change, more frequent crop failures in Brazil, and even greater economic uncertainty globally. 


Rather than conserving tropical forests, current political and economic forces are accelerating us towards an irreversible climatic tipping point. Climate change is already beginning to degrade remaining forests. Indigenous people and forest communities, responsible for protecting almost half of the Amazon, are losing their land rights and protections. Roads, railroads and dams are being proposed and constructed to unsustainably exploit pristine forests.Yet, the science is clear: Additional deforestation would materially decrease the productivity of existing Brazilian farmland, accelerating global warming while reducing food security. This is frequently misunderstood, but our data is unequivocal.

So how do we move forward? We must recognize that the current development model, which assumes that nature stands in the way of development, is wrong. We must shift to a model, which recognizes that forest conservation and development can go hand in hand. This was already achieved in the mid-2000s when Brazil reduced its deforestation rates by about 80 percent while increasing its soybean and beef production. 

There are a number of proven ways that this can be achieved again in Brazil. These solutions include eliminating land grabbing and land speculation through federal designation of public forests. Brazil must reduce legal deforestation on private property through payments for ecosystem services and incentivize production increases on existing lands through targeted investments. There is also a need to foster economic, environmental and social improvements through assistance to smallholder farmers and create the civil infrastructure to both reduce reliance on fires as part of the clearing process, and to put out fires. 

Yes, these all cost money — but they also will yield environmental, economic and social gains for Brazil and the world and help reduce global climate change. 

Ane Alencar is director of science at IPAM-Amazonia.

Michael Coe is senior scientist and Amazon program director at Woods Hole Research Center.