While Internet of Things (IoT) smart farming promises significant benefits in terms of enhancing efficiency, effectiveness, and productivity, and has witnessed increased adoption in agriculture in recent years, it still remains underutilised within the agricultural sector. Despite well-intentioned efforts by policymakers, the transformation of traditional agricultural systems into smart farms remains a formidable challenge. Drawing on technology acceptance literature and Prospect Theory (PT), this article explores, compares, and prioritizes the factors that influence IoT smart farming adoption, considering both the expected gains and losses. Survey data collected from 265 farmers in Thailand was analysed using structural equation modelling (SEM) to test our hypotheses. The results demonstrate that IoT smart farming is significantly influenced by both the perceived expected gains from its adoption and the perceived expected losses from climate change in the case of not adopting IoT smart farming. However, in contrast to PT, the impact of losses is not greater than that of gains. This article offers valuable insights that are essential for shaping sustainable farming practices and informing policy frameworks in the face of mounting challenges posed by climate change.