IntroductionIncreasing temperature and elevated atmospheric carbon dioxide levels could impact the survival of stress-adapted bacteria. Method and resultsIn this study, RNA sequencing was performed to quantify Escherichia coli BL21 (DE3) gene expression in culture media under environmental temperature (27 °C and 42 °C) and carbon dioxide (0.2 % and 6 % v/v) conditions. Differential gene expression analysis between low temperature and different carbon dioxide conditions revealed up-regulated genes such as ldtC and bioA, optimising cell wall integrity and nutrient uptake. While, the downregulation of genes such as malK suggested a metabolic adaptation. Low temperature and high carbon dioxide levels enhanced bacterial tolerance to environmental stress. Under optimal temperatures, Escherichia coli adapts through various metabolic pathways while engaging in different processes at low temperatures and carbon dioxide levels, with temperature having a greater impact on gene expression than carbon dioxide levels. This study shows that complex metabolic activities are activated when both temperatures and carbon dioxide levels are combinsed, affecting antimicrobial resistance, nutrient acquisition, and adaptation strategies. ConclusionEach condition exhibited mechanisms to enhance cellular resilience and adaptation to stress, focusing on cellular integrity, optimising energy utilisation, and activating stress response pathways. Impact statementThe findings stress the importance of continued research to understand the implications of climate change on microbial transcriptomes comprehensively.