The direct impacts of mines and dams are eclipsed by the indirect effects, as thousands of workers follow mega- development projects into protected areas.
All eyes are on Brazil following the re-election of Dilma Rousseff as president after an eventful campaign in which the strongly pro-environment candidate Marina Silva was squarely defeated.
Now, the country's green credentials are seriously at risk. In a new report in the journal Science, researchers from Brazil and the UK (including myself) highlight the danger of new plans to allow mining and dams in protected areas and indigenous lands.
Congressional debates to approve or reject proposed legislation will decide if Brazil will retain its hard-won status as what The Economist calls "the world leader in reducing environmental degradation".
The new government is at a crossroads: either maintain the integrity and long-term future of its globally significant ecosystems - or favour industrial interests by allowing 10% of even strictly protected areas to be mined.
While the proposals include mitigation measures (protecting land elsewhere) these are unrealistic and also inadequate because they fail to account for the indirect impacts of mines.
Developing mines and hydropower dams in protected areas would represent a reversal for Brazilian law-makers and a body blow to environmental agencies, credited with drastically reducing Amazonian deforestation over the past decade.
The gruesome twosome - damming and mining
Mega-projects have mega-impacts and in the Amazon, mining and damming go hand in hand. Mining is energy intensive and is one of the underlying reasons for Brazil developing dozens of large hydropower plants in Amazonia.
Hydroelectric dams can harm both society and the environment. For example, I was alarmed to see how severe flooding in Rondônia state this year led to economic paralysis and the spread of water-borne diseases in towns and countryside along the Madeira River.
The flooding of the Madeira in both Brazil and upriver in Bolivia was suspected to have been caused by the recently completed Jirau hydropower dam. Under current plans, very few protected areas will remain free from the influence of hydroelectric dams.
Mining projects such as the enormous Carajás iron ore mine in eastern Amazonia (see photo), powered by construction of the controversial Tucuruí dam in the 1970s, are only the tip of the iceberg. Mineral extraction in Brazil is poised to expand into what were previously considered no-go areas for industrial development.
Protected lands are a essential safeguard
Our research found that in the Amazon alone 34,117km2 of strictly protected areas and 281,443km2 of indigenous lands are in areas of registered mining interest. Forget football fields, this is an area larger than the whole of the UK.
The direct impacts of mines and dams are eclipsed by the indirect effects, as thousands of workers follow mega-development projects into protected areas. Rapid population growth in service towns causes urban areas, roads and farmland to expand into surrounding forests.
By 2000, Brazil had created the world's largest protected area network, covering an enormous 2.2m km2 - an area the size of Greenland.
These parks have been highly effective. For example, by reducing deforestation rates to only 10-15% of those in surrounding areas, Brazil's protected areas contribute to mitigating future climate change.
The beneficiaries of climate mitigation range from farmers in the south of Brazil who depend on Amazonia for their rainfall, to the poorest people in developing countries who stand to bear the brunt of global warming, sea-level rise and extreme climatic events.
Brazil's protected areas go far beyond just saving the forests themselves and support traditional peoples, including rubber-tappers and Brazil-nut harvesters.
In addition, indigenous lands provide a safe space to maintain the traditions and cultures of the country's 305 indigenous ethnic groups, including 69 uncontacted groups.
Brazil gets richer, but protected areas remain under-funded and under-staffed
Get-rich-quick mining is not a new threat to Brazil's unique ecosystems. I have witnessed the decade-long struggle of a strictly protected area, the Jari Ecological Station in Pará, to remove illegal gold-mining from within its borders.
However, it is harrowing to now see 71% of the park (an area larger than Greater London) being under official consideration for mining operations. Even if 'only' 10% of the park is used for mining, indirect effects will change it for ever.
Relevant federal departments need adequate resources to ensure government decisions are made democratically and with reliable impact assessments. Chronic under-staffing in Brazil's protected areas means that many lack basic information on baseline environmental conditions and diversity of plants and animals.
Buffer areas designed to protect parks from external threats are put at risk, and a lack of staffing and data puts ICMBio (the agency responsible for protecting parks) in a weak position from which to assess the potential impacts of dams or mining on the integrity of a park.
Brazil's population is growing and increasingly wealthy, which means higher demands for energy and food. Some difficult decisions will have to be made.
However, environmental impact assessments and mitigation measures (in some cases impossible to achieve and in most cases not implemented anyway) surrounding proposed mega-projects have fallen short of international best practice and largely ignore indirect impacts.
I hope that Brazil reasserts its status as a leader of green development and does not legislate against her national treasures.
Luke Parry is Lecturer in Ecosystem Services, Lancaster Environment Centre at Lancaster University. He does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.