When scientific researchers are sufficiently resourced to conduct their research and communicate their findings, the knowledge produced can underpin technology and policy outcomes related to the environment and society. However, interference with the research process and knowledge exchange of results has been observed in several countries, particularly for environmental researchers. This study reviews the history of interference in science in Canada and offers a definition of the term interference in science. To understand the prevalence and impacts of interference, researchers in the environmental studies and sciences in Canada were surveyed. The results indicate that these researchers seem overall better able to conduct and communicate their work than in the past decade, however, the high prevalence of ongoing interference remains a cause for concern. Considering the potentially severe consequences of interference for the well-being of researchers, science communication, and democratic governance, I recommend solutions to limit interference and improve knowledge exchange.