This article examines the American Society of Heating, Refrigeration, and Air-conditioning Engineers (ASHRAE) and its response to the ozone crisis in the 1970s, highlighting the science-skepticism that hindered responses to environmental issues in the twentieth century. Although well-positioned to address ozone depletion by developing safer chemical alternatives, ASHRAE resisted regulatory changes, framing concerns over CFC emissions as an attack on engineering and American technological dominance. Their rhetoric of doubt persisted for over a decade, even after corporations like DuPont acknowledged environmental harm and adopted chlorofluorocarbon controls. This study reveals how skepticism within scientifically literate communities can complicate environmental responses and explores the role of professional identity in shaping environmental and technical policy decisions.