Jacqueline Harpman (1929-2012), Catherine Barreau (1965) and Antoine Wauters (1981) are three writers with very different literary trajectories, styles and fortunes. In addition to be part of Belgian French-language literature, they have in common that they have ventured beyond the boundaries of reality, at least once in their work, without claiming to be writers of strange or fantastic genres. Moi qui n'ai pas connu les hommes (Jacqueline Harpman, 1995), L'Escalier (Catherine Barreau, 2016) and Moi, Marthe et les autres (Antoine Wauters, 2018) can be described as post-apocalyptic novels. This article analyses these three novels in order to detect traces of an environmental concern, which an ecocritical reading can shed light on. In the three studied texts, we observe the use of another language, not in the primary sense of the term, but in that of a polyphony understood as the particular use given to the different narrative voices. More broadly, the article questions the place that literature can occupy in a world with a deleterious climate and what can be offered to us by the gaps and liberties taken in the face of reality, when the horizon of this same reality offers (no more) than a landscape of future devastation and escapes. ; Jacqueline Harpman (1929-2012), Catherine Barreau (1965) e Antoine Wauters (1981) são três escritores com trajetórias, estilos e fortunas literárias bastante diferentes. Além de seu pertencimento à literatura belga de língua francesa, eles têm em comum o fato de terem se aventurado além das fronteiras do real, pelo menos uma vez em sua obra, sem a pretensão de serem escritores do estranho ou do fantástico. Moi qui n’ai pas connu les hommes (Jacqueline Harpman, 1995), L’Escalier (Catherine Barreau, 2016) e Moi, Marthe et les autres (Antoine Wauters, 2018) podem ser qualificados como romances pós-apocalípticos. Neste artigo, propõe-se analisar esses três romances com o objetivo de rastrear os traços de uma preocupação ambiental, que uma leitura de abordagem ecocrítica permite elucidar. ...