The ICT sector is a significant contributor to global emissions, accounting for about 3% and surpassing even the aviation industry, largely due to the increasing demands from big data, cryptocurrencies, and AI. Software engineers have a unique opportunity to mitigate this impact by implementing sustainable IT practices, which not only reduce CO2 emissions but also lower costs. Key strategies include using observability tools to measure energy consumption, creating optimization plans to address underutilized resources, scaling systems to zero to match current demands, scheduling workloads efficiently, optimizing digital artifacts, and selecting data centers based on their carbon footprint. Continuous measurement and optimization cycles are crucial for ongoing improvement, and sharing successful sustainability practices can amplify global impact. The time to act is now, and collaboration through platforms like the CNCF Technical Advisory Group on Environmental Sustainability can help drive meaningful change in the industry.