This paper investigates the detection of carbon dioxide at room temperature using microfabricated, interdigitated capacitive (IDC) sensors coated with an amino-functionalized sensing film. Sensing experiments performed at temperatures ranging from room temperature to 100°C indicate two different temperature-dependent sensing mechanisms. Around room temperature, physisorption dominates the sensor response, resulting in fast signal transients and negative capacitance changes. Above 80°C, chemisorption appears to dominate, resulting in larger, positive capacitance changes with longer signal transients.