This chapter investigates the integration of science, technology, engineering, and mathematics (STEM) disciplines into climate change education by exploring three levels of curriculum integration—multidisciplinary, interdisciplinary, and transdisciplinary. The chapter then focuses on how teachers participating professional development program, designed to bridge theoretical understanding with real-world problem-solving, created integrated curricula around authentic problems. Drawing on data from the climate change instructional designs developed by the participant teachers, the chapter presents how teachers from different STEM disciplines integrate their subjects to address climate change issues at individual, local, regional, and global scales. Through analysis of 32 teachers’ instructional designs, the research reveals diverse approaches to STEM integration, with middle school science teachers showing the greatest variety in addressing climate issues across all scales, while other disciplines tend to focus on specific scales. The findings highlight the potential of integrated STEM approaches to enhance climate change education while noting the challenges in achieving effective integration across different scales and disciplines. The chapter presents how teachers create authentic learning experiences that connect disciplinary knowledge with real-world applications, while also identifying opportunities to enhance professional development support for addressing climate change at broader scales through integrated STEM instruction.