Fake controversies have influenced policy making on health and environmental issues for decades, resulting in major implementation setbacks worldwide. As a case study, in this paper we examine fake controversies produced by a small group of active Brazilian researchers that have seriously impacted environmental conservation, particularly in issues related to deforestation and climate change. Based on the literature, we develop a typology of strategies deployed in fake controversies, which include manufacturing uncertainty, misusing scientific credentials, and disregarding scientific literature. Afterwards, we examine the influence of this group of contrarians at the National Congress. We then analyze the fake controversies promoted by these contrarians and argue that, to properly understand them, we need to consider a strategy so far overlooked in the literature: the manufacture of “pseudo-facts”, namely, affirmations at odds with the established literature but that strives to appear as scientific facts. Unlike other contexts, in which contrarians have mainly sought to cast doubt on consensual issues by arguing that there are still considerable uncertainties surrounding them, in Brazil pseudo-facts on deforestation have been produced and published outside the peer-reviewed literature. We conclude the study with recommendations on how to oppose fake scientific controversies that threaten environmental conservation in general
