Keep the Amazon niobium in the ground.

• A fallacious narrative could trigger unprecedent devastation. • Niobium deposits in well conserved biodiverse area in Amazon are investigated. • Scenarios reveals large extent of deforestation caused by new projects. • Cumulative impact assessment is necessary to better appraise mining projects. • Risk of making ill-informed decisions without a comprehensive assessment of adverse impacts. Political pressure to expand mining to protected areas in near-pristine regions urges strategic-level anticipation of the impacts of infrastructure provision necessary to support mining development. Undeveloped niobium deposits in Northwestern Amazon were broadcasted as of primary interest of Brazilian politicians, what called attention to the risks to ecosystem conservation and indigenous people in this key biodiversity area. Given this current threat, we investigated different scenarios of mining expansion in the region and found that it would entail significant cumulative forest loss, affecting biodiversity and ecosystem services. If conciliation of niobium exploitation and conservation is possible, it would require strengthening the assessment of cumulative impacts under the current environmental impact assessment process by: (i) providing terms of reference with straightforward requirements and criteria; (ii) produce a public database and standardize procedures for data acquisition; (iii) use and development of retrospective and prospective investigative protocols. These ingredients are lacking in the current political trend of weakening environmental legislation and governance, therefore Amazon niobium should be kept in the ground. [ABSTRACT FROM AUTHOR]