Forest and Water Programme

The forest-water nexus and fires in the Amazon


During the past couple weeks, plenty of photos, videos and posts about the Amazon forest fires have been circulating in social media:

“The largest rainforest in the world is on fire, for the 16th day. And the media is not covering it.”

“The Amazon is burning for 3 weeks, and I am just now finding out because of the lack of media coverage”. 

“It's been eighteen days since the fire is over, and these eighteen days I can't stop crying. The media is trying to hide the sad reality that the Amazon is experiencing right now.”

But what is the truth about what is really happening in the world’s largest and most biodiverse rainforest? Is the fire out of control? Where are these forest fires happening, and how did they start? Why was the media delayed in reporting this disaster? Is the smoke from the fire really reaching the southern cities in Brazil, such as São Paulo? How do the fires affect the quantity and quality of water since the link between forests and water is so important in this region?

There are many unanswered questions that need to be addressed, but the first point is to understand how the fire began and its relation with the land-use change in the region. 

In undisturbed portions of the Amazon forest, humidity is high even in the dry season, preventing fires from spreading and affecting the forest. When the forest structure is modified and natural regimes are negatively impacted, the problems begin. This is exactly what deforestation does. 

In the Amazon, the deforestation process basically has three steps. First, trees with valuable wood are harvested in unplanned and unsustainable ways. Then, a pair of adapted tractors connected by chains pass through the forest, destroying everything in their path (a technique known as correntão in Brazil). The fires are the third and last step of deforestation. Since the forest structure was destroyed, the vegetation can no longer retain humidity, making the area susceptible to fire. This method is used by farmers to clear the area for agriculture uses.

This process is precisely what is happening in the Amazon right now. The main driver of these forest fires is the anthropogenic land-use change (forests converted into agricultural land). Recent data from the Amazon Environmental Research Institute (IPAM) shows that the number of forest fires and deforestation are closely linked; municipalities that experience the highest number of fires also have the highest rates of deforestation. Furthermore, the data also shows that the current dry season is within normal parameters and therefore, current meteorological conditions do not explain such an abnormal increase in forest fires.

Flying rivers: carrying substances other than water

A topic widely discussed on social media was the smoke and smog that affected São Paulo, Brazil’s largest city, on Monday, 19 August. Some of the smoke generated by the fires in the Amazon drifted to the south, turning São Paulo’s skies dark even at midday. Analyses carried out by local universities confirmed the presence of particles derived from forest fires in the rainwater in São Paulo. 

This effect can be explained by the “flying rivers” (click here to learn more about it). Besides carrying water vapor and humidity, these enormous pumps can also carry other substances. This flying rivers are then transformed into “smoke dry rivers”. This was seen in satellite images that showed changes in the color of clouds as well as smoke clouds over different cities in Brazil (Porto Velho, Cuiabá and even in Livramento, in the extreme south of the country).

The importance of Amazon for water provision

These forest fires are part of a larger problem: deforestation. Therefore, it is vital to combat and prevent deforestation in order to tackle forest fires. Apart from its impressive biodiversity, its indigenous populations and its role as a carbon sink, the Amazon rainforest contributes to the water provision of millions of people, not only in Brazil but also in other South American countries. Its importance, thus, is not only regional, but continental. 

Let’s raise awareness on this topic and the drivers of forest fires. The Amazon is the target right now but this is also a global issue. If we truly want to tackle climate change with as little impact as possible to the global economy and development, we need to support sustainable ways and best practices in forest management. Deforestation is not one of them.