The Amazon rainforest is the biological heart of planet Earth. Its variety of mammals, amphibians, and reptiles number in the hundreds, with these groups together accounting for more than a thousand identified species. Birds and fish are even more diverse, with 1,300 and 2,400 species, respectively. Vascular plants are estimated at 50,000 species. The diversity of insects and fungi is estimated to be in the millions, but most have yet to be described. This biological diversity in the Amazon is the result of geological and ecological forces in the last 30 million years that, due to the uplift of the Andes Mountains, created a variety of soil, climatic, and hydrological conditions.
In addition to being a global biodiversity hotspot, the Amazon also has remarkable cultural diversity. Spanning Brazil, Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela, the Amazon region is home to around 44 million inhabitants, 2.2 million of whom are of Indigenous origin, speaking around 300 different languages. Brazilian anthropologist Darcy Ribeiro has noted that the Indigenous peoples of the Amazon long knew all about the region’s biodiversity, including what uses each species was or was not good for—knowledge accumulated over more than 10,000 years of experience with the forest.
Indigenous peoples living in the Amazon are highly dependent on the biological resources provided by forests and rivers, such as fruits, seeds, bamboo, and fish. These resources, managed by the original peoples, are used to obtain plant and animal fats, carbohydrates, and proteins, as well as for making bows, arrows, canoes, and housing, among other things. These life supplies are essential for Indigenous survival to this day. Due to this centrality of biological resources to their livelihoods, Indigenous peoples consider everything in the forest to be sacred.
The problem is that the biological and cultural diversity of the Amazon has been suffering an unprecedented decline. Indigenous peoples of the Baniwa, Munduruku, Suruí, and Kichwa nations reported in 2023 how illegal activities and climate change are affecting their sacred places and ways of life. Similarly, harvesters of non-timber forest products have reported for decades that deforestation has reduced populations of trees such as andiroba (Carapa spp.), copaiba (Copaifera spp.), and jatobá, also known as Brazilian copal (Hymenaea spp.). Scientific studies confirm reports from Indigenous peoples and local communities that the Amazon is close to surpassing the limits that sustain its climate, environmental stability, and human well-being.
In this context, understanding how illegal environmental activities and climate change harm the livelihoods of Amazonion populations, and humanity in general, is necessary for designing a sustainable development model for the Amazon. Devising a new model is challenging—it needs to keep the forest standing and the rivers flowing and generate prosperity for Indigenous peoples and local communities. As we show here, the Amazon’s environmental challenges are linked to a history of unsustainable exploitation of natural resources associated with illicit activities. With a view to reversing the climate crisis and biodiversity loss, we conclude by outlining strategies that scientists and local populations in the Amazon recognize would promote significant and permanent changes.
Deforestation: Biodiversity Loss and Climate Change
Deforestation is the leading cause of biodiversity loss in the Amazon. For decades, the Amazon rainforest has had the highest deforestation rate among tropical regions on the planet. From 2001 to 2018, average annual deforestation across the entire forest was approximately 17,000 square kilometers (over 6,500 square miles). The Brazilian Amazon concentrates most of the deforestation, with an average annual rate of 13,832 square kilometers between 1988 and 2021, ranging from a high of 29,059 square kilometers in 1995 to a low of 4,571 square kilometers in 2012. Today, more than 800,000 square kilometers of the Amazon rainforest have been deforested in Brazil.
Research by the Instituto Centro Vida has shown that, within the different states of the Brazilian Amazon, the proportion of deforestation that is illegal varies between 65 percent and 99.7 percent. This means that most deforestation takes place without the consent and authorization of the responsible environmental agencies. Agricultural expansion is the main driver of deforestation in the Amazon, and extensive cattle ranching is the main economic activity in deforested areas.
However, livestock activity in the Amazon is almost always characterized by very low productivity and high environmental impact. As a result, development based on deforestation has not yet resulted in wealth generation or improvements in quality of life for those who live in the Amazon. For example, the Brazilian Institute of Geography and Statistics (IBGE) estimates that 44 percent of people in the state of Amazonas live in poverty (over 1.7 million people). Several measures of socioeconomic development—such as Gross Domestic Product, Human Development Index, Social Progress Index, and Social Vulnerability Index—place the region below average compared to other regions of Brazil, confirming the inequality.
According to reports from Indigenous peoples and local communities, deforestation threatens sustainable harvesting, such as the collection of Brazil nuts (Bertholletia excelsa) and bamboo stalks (Bambusa spp. and Guadua spp.). Although Brazilian law prohibits deforestation of Brazil nut trees, activities related to Brazil nut production have declined in the most deforested municipalities of the Amazon. Additionally, many forest areas where bamboo is naturally occurring are within cattle ranches today. This shows how deforestation for the development of pastures has impacted sustainable harvesting, practiced for centuries by local communities and for thousands of years by Indigenous peoples.
Deforestation also causes regional climate change by reducing forest biomass and altering the interaction between the biosphere and atmosphere. That is, deforestation alters the balance of energy and water on the Earth’s surface: when the forest is replaced by non-forest vegetation such as pastures or soy cultivation, the balance of radiant energy absorbed by vegetation and used in the process of evapotranspiration (latent heat) is reduced, while energy related to the heating of the planetary boundary layer (sensible heat) is increased. There are indications that the complete replacement of forest by pastures or soy cultivation can increase the average regional temperature by between 3ºC and 4°C and reduce the volume of annual rainfall by between 9 and 25 percent.
Scientists have shown that the temperature in the Amazon Basin has increased by more than 1°C since the 1970s and that the dry season in the south and east of the forest has increased by between four and five weeks. The increase in temperature and length of the dry season is even greater in areas that have been most deforested. Additionally, the increase in the frequency of extreme droughts, such as those that occurred in 2005, 2010, 2015-16, and 2020, mostly caused by global climate change, has been associated with considerable growth of degraded areas. It’s clear that climate changes caused by human activities are already part of the Amazon’s recent history.
The Amazon plays a key role in recycling water and producing moisture flows, which transport clouds and rain to distant regions of the forest outside the Amazon Basin. As research by agronomist and climatologist Eneas Salati showed in the 1970s, the forest recycles rain moisture five to eight times before it leaves the region, which serves an important ecosystem function that deforestation can compromise. This phenomenon of moisture flow formation in the forest and transportation to other regions is known as flying rivers. In addition to affecting local communities, deforestation in the Amazon can thus damage water supplies in several parts of South America.
Translated from Portuguese by NACLA.
Diego Oliveira Brandão is a member of technical-scientific secretariat of the Science Panel for the Amazon.
Julia Arieira is a member of technical-scientific secretariat of the Science Panel for the Amazon.
Carlos Afonso Nobre is co-chair of the Science Panel for the Amazon and a researcher at the Institute of Advanced Studies at the University of São Paulo.