At some point in time, the Amazon River flowed westward, perhaps as part of a Protocongolian river system from within present day Africa, when the continents were joined as part of Gondwana. Fifteen million years ago, the Andes were formed by the collision of the South American plate with the Nazca plate. The uplift of the Andes and the joining of the Brazilian and Guyana rock massifs closed the river and caused the Amazon to transform into a vast inland sea. Gradually, this inland sea became a huge freshwater swampy lake and the marine survivors became accustomed to life in freshwater. For example, the fresh waters of the Amazon are now home to more than 20 species of rays, most of them closely related to those of the Pacific Ocean.

About ten million years ago, the waters broke through the sandstone to the west and the Amazon began to flow eastward. At that time, the Amazon rainforest was born. During the Ice Age, the sea level dropped and the great Amazon lake quickly emptied and became a river. Three million years later, ocean levels dropped enough to expose the Central American isthmus and allow the mass migration of mammal species between the Americas.

The Ice Age caused the retreat of tropical rainforests around the world. Although controversial, much of the Amazon is thought to have reverted to savanna and montane forest (see Ice Age and Ice Age). The savanna divided the rainforest fragments into “islands” and separated the existing species for periods long enough to allow genetic differentiation (similar rainforest regression occurred in Africa. Core samples from the delta suggest that the mighty Congo Basin was also free of rainforest at this time). When the glacial periods ended, the rainforest reassembled and individual species became sufficiently differentiated to form separate species designations, increasing the enormous diversity of the region. About 6,000 years ago, the sea level rose about 130 meters, causing the river to overflow as a long, gigantic freshwater lake.

Today, the Amazon River is the largest flowing river on Earth, carrying more than five times the volume of the Congo or twelve times that of the Mississippi, and draining an area nearly the size of the fortyeight contiguous states. During the high water season, the mouth of the river can be 300 miles wide and up to 18 billion cubic meters (635 billion cubic feet) of water flows into the Atlantic every day. That discharge, equivalent to 209,000 cubic meters of water per second (7.3 million cubic feet/sec), could fill more than 7.2 million Olympicsize swimming pools a day or meet New York City’s freshwater demands for nine years.


Although the Amazon basin is home to the world’s largest rainforest, the region is made up of many other ecosystems ranging from natural savannas to swamps. Even the rainforest itself is highly variable: tree diversity and structure vary according to soil type, history, drainage, altitude and other factors. This is discussed in more detail in the Amazon rainforest ecology section.


The Amazon is home to more plant and animal species than any other terrestrial ecosystem on the planet: perhaps 30% of the world’s species are found here. The following figures are an example of its impressive levels of biodiversity:

  • 40,000 plant species
  • 16,000 species of trees
  • 3,000 species of fish
  • 1,300 species of birds
  • More than 430 species of mammals
  • More than 1,000 amphibians
  • More than 400 reptiles


The Amazon has a long history of human settlement, but in recent decades the pace of change has accelerated due to human population growth, the introduction of mechanized agriculture and the integration of the Amazon region into the global economy. Huge quantities of raw materials produced in the Amazon are now exported to China, Europe, the United States, Russia and other countries: meat and leather, timber, soybeans, oil and gas, and minerals, to name a few. This change has had a substantial impact on the Amazon.

This transition from remote periphery to cog in the global economy has led to largescale deforestation and forest degradation in the Amazon: more than 1.4 million hectares of forest have been cleared since the 1970s. An even larger area has been affected by selective logging and forest fires.

Conversion to cattle grazing is the main direct driver of deforestation. In Brazil, more than 60% of deforested land ends up as pasture, most of which has low productivity, with less than one head per hectare. In much of the Amazon, the main purpose of cattle ranching is to establish territorial claims, rather than to produce meat or leather. However, marketoriented livestock production has expanded rapidly in the last decade.

Industrial agricultural production, particularly soybean farms, has also been a major driver of deforestation since the early 1990s. However, since 2006, the Brazilian soybean industry has imposed a moratorium on clearing new forests for soybeans. The moratorium was the direct result of a Greenpeace campaign.

Mining, subsistence agriculture, dams, urban expansion, agricultural fires and timber plantations also cause significant forest loss in the Amazon. Logging is the main driver of forest disturbance and studies have shown that deforested forests, even if selectively cut, are much more likely to suffer from eventual deforestation. Forest roads allow farmers and ranchers to access previously inaccessible forest areas.

Deforestation is not the only reason the Amazon is changing. Global climate change is having a strong impact on the Amazon rainforest. Rising temperatures in the tropical Atlantic are reducing rainfall in large parts of the Amazon, causing droughts and increasing the forest’s susceptibility to fires. Computer models suggest that, if the current rate of warming continues, much of the Amazon could change from rainforest to savanna, especially in the south of the region. This change could have dramatic economic and ecological consequences, including decreasing the rainfall that currently feeds the regions that generate 70% of South America’s GDP and causing huge carbon emissions due to forest decomposition. These emissions could further exacerbate climate change.


Although the destruction of the Amazon rainforest continues, the overall rate of deforestation in the region decreased between mid2000 and mid2000, mainly due to a sharp reduction in deforestation in Brazil. However, deforestation has steadily increased in the region in recent years.

The decline in the rate of deforestation in Brazil between 2004 and 2012 is attributed to several factors, some of which are controlled and some of which are not. Between 2000 and 2010, Brazil created the largest network of protected areas in the world, most of which are in the Amazon region. In 2004, the government launched a program to reduce deforestation that included improved law enforcement, satellite monitoring and financial incentives for compliance with environmental laws. Independent prosecutors have played a particularly important role in prosecuting illegal activities in the Brazilian Amazon. The private sector has also become involved, especially since 2006, when major crushing companies established a moratorium on new soybean deforestation. This soy moratorium was followed by the “Cattle Agreement”, whereby major slaughterhouses and meat processors pledged to source cattle only from areas where environmental laws are respected.

However, these conservation initiatives began to fail in the Brazilian Amazon in the mid2010s. Large cattle producers circumvented the rules by recycling their cattle, while financial incentives for forest conservation failed to materialize to the point of changing landowner behavior. The Temer and Bolsonaro governments have dismantled environmental regulations, reduced environmental enforcement, stripped protection from conservation areas and indigenous territories, and encouraged a wide range of industries (mining, forestry, agribusiness) to expand mining and conversion in the Amazon. In 2019, deforestation in Brazil began to accelerate rapidly.


Violence persists in Amazon region where Pereira and Phillips were killed (August 2, 2022)

  • On July 15, armed illegal miners threatened government forest guards near the site where British journalist Dom Phillips and Brazilian indigenous expert Bruno Pereira were murdered in June.
  • Days after the threats, federal prosecutors charged three men with the murders of Phillips and Pereira, but activists and lawmakers say the investigation must be expanded to identify the possible involvement of criminal organizations.
  • According to activists, threats against government officials, including Pereira, have occurred for decades, but the situation has worsened under the administration of President Jair Bolsonaro.
  • The government’s weakening of environmental agencies and Bolsonaro’s antiindigenous rhetoric have created a sense of impunity, encouraging Amazon criminals to retaliate against activists and environmentalists who expose their illegal activities.

Organized crime drives violence and deforestation in the Amazon, study finds (Aug. 1, 2022)

  • Rising rates of deforestation and violence in the Brazilian Amazon are driven by national and transnational criminal networks, according to a study.
  • According to experts, criminal organizations involved in activities ranging from illegal logging to drug trafficking often threaten and attack environmentalists, indigenous peoples and the law enforcement agencies that try to stop them.
  • In 2020, the Brazilian Amazon had the highest homicide rate in Brazil, with 29.6 murders per 100,000 inhabitants, compared to the national average of 23.9, with the highest rates occurring in municipalities with the highest deforestation.
  • According to experts, the systematic dismantling of environmental protection and control agencies by the current government has strengthened these criminal organizations, which are now “wellconnected, wellestablished and very powerful”.

From agribusiness to oil, from nuclear to submarines: welcome to the PutinBolsonaro antienvironmental alliance (commentary) (August 1, 2022)

  • Brazil’s dependence on Russian fertilizers has contributed to Jair Bolsonaro’s friendly relationship with Vladimir Putin, as well as to the environmental impact on the South American country.
  • In this editorial, Nikolas Kozloff, an American academic, author and photojournalist, discusses some of the implications of the growing ties between the two leaders, such as deforestation in the Amazon, extractive industries and infrastructure projects.
  • As Amazon burns, only climate can avert catastrophe, say experts (26 Jul 2022).
  • The Brazilian Amazon recorded the highest number of fires in the last 15 years in June, with 2,562 large fires detected, an increase of 11.14% over 2021.
  • In the first half of the year, there were 7,533 large fires, the highest number since 2019, according to data from the National Institute for Space Research.
  • On June 23, the Brazilian government issued a decree banning the use of burning for forest management throughout the country for the next 120 days.
  • Experts are skeptical of the ban, as similar measures have failed to curb fires in previous years, and argue that the weather is the only thing that can help curb the increase in fires as the dry season progresses.

Brazil’s new deforestation data council raises fears of censoring forest loss and fires (22 Jul 2022)

  • A new council created by the Brazilian government to examine deforestation and forest fire data provided by the country’s space agency has been widely criticized as a political ploy to promote President Jair Bolsonaro’s reelection bid.
  • The National Institute for Space Research (INPE) has been providing and analyzing data on deforestation and forest fires in the Amazon since 1988 and is recognized worldwide for its monitoring expertise, but has been excluded from the new council.
  • Bolsonaro’s government has questioned the credibility of INPE’s data since taking office in 2019, prompting outrage from scientists and researchers who said data showing a spike in deforestation under Bolsonaro’s government was false.
  • Experts fear the new council could prevent the release of annual deforestation data, scheduled to coincide with this year’s elections, which are expected to show an alarming increase in forest loss and fires.

First Freshwater Mangroves Discovered in Brazilian Amazon Delta (20 Jul 2022)

  • Researchers on an expedition in the Amazon delta have discovered that mangroves grow in freshwater, a phenomenon never before documented in deltas or coastal mangroves anywhere else in the world.
  • The mangroves, ignored in previous satellite mapping work, increase the known area of mangroves in the region by 20%, or 180 square kilometers more.
  • Mangroves are a more effective carbon sink than other tropical forest types: more than 8% of all the world’s carbon stocks are found in Brazilian mangroves.
  • Despite their numerous ecosystem services, mangroves are not well protected or funded in Brazil.

245 Million Initiative to Create and Maintain Protected Areas in Colombia (Jul 14, 2022)

  • Patrimonio Colombia is a $245 million initiative to support the creation, expansion and enhancement of 32 million hectares (nearly 80 million acres) of terrestrial and marine protected areas in the country over the next decade.
  • This is a Funding for Permanence Projects (FPP) initiative, which means that conservation funds have been secured from the public and private sectors for the implementation of farreaching, longterm projects.
  • If Heritage Colombia succeeds, the country will see 26% of its land territory and 30% of its oceans protected, fulfilling part of its 30×30 commitment eight years early.

Amazon deforestation fastest in one year since 2008 (Jul 8, 2022)

  • Deforestation in the Brazilian Amazon has recorded the fastest start to the year since 2008, according to government data released today.
  • Deforestation alert data from Brazil’s National Institute for Spatial Research shows that 3,988 square kilometers of forest have been cleared in the Brazilian Amazon since January 1, a 17% increase over last year.
  • In 2021, deforestation in the Brazilian Amazon reached its highest level in 15 years.

Habitat loss and climate change bring blue macaw back under threat (Jul 4, 2022)

  • The blue macaw, the world’s largest flying parrot, is one step closer to reentering Brazil’s endangered species list, less than a decade after intensive conservation efforts succeeded in removing it from the list.
  • The latest assessment has yet to be made official by the Ministry of Environment, which is likely to publish the updated endangered species list next year.
  • Conservation experts attribute the birds’ decline to habitat loss due to fires in the Pantanal wetlands and continued deforestation in the Amazon and Cerrado.
  • Climate change also poses a serious threat, subjecting the birds to temperature changes that can kill eggs and chicks, and causing heavy rains that flood their preferred nesting sites.

Protecting the Brazilian Amazon could be a bargain, if the government is willing to pay (Jul 4, 2022)

  • A new study shows that conserving 350 million hectares of the Brazilian Amazon83% of the biomewould cost between $1.7 billion and $2.8 billion a year.
  • This is a fraction of the $5.3 billion the European Union spends annually to maintain its millions of hectares of protected areas.
  • Current protected areas cover 51% of the Brazilian Amazon, but, according to experts, they are not sufficient to maintain the biome’s biodiversity and need to be expanded.
  • Although the cost of protecting the Amazon is hundreds of times lower, hectare for hectare, than in the EU, it is much higher than what the Brazilian government spends on environmental conservation.