Digital Twins in Mechanical Engineering, and a Brief Overview on Decarbonization and Sustainable System Optimization

Climate change is pushing industries to cut down emissions fast, and mechanical engineering is playing a key role in that shift. One technology making a real difference is the digital twin — a live, virtual model of a machine or system that mirrors what’s happening in real life. It lets engineers track performance, test ideas, and catch problems early, all without interrupting operations. This paper looks at how digital twins are helping reduce carbon emissions across fields like manufacturing, energy, transport, and industrial systems. The benefits are clear: more efficient designs, better maintenance planning, and smarter use of energy. DTs also help track emissions in real-time and spot patterns that wouldn’t be obvious otherwise. In some setups, they've helped cut operational emissions by nearly 30%. Still, the use of digital twins isn’t as widespread as it could be. A lot of companies struggle with setup, especially when different machines and platforms don’t work well together. There’s also a lack of training and no strong, shared framework for using DTs in mechanical systems specifically. This paper explores those challenges and suggests how industries can move forward — by improving standards, encouraging collaboration, and giving engineers the tools and knowledge to apply this technology well. Digital twins aren’t just helpful add-ons; they have the potential to reshape how we design, monitor, and improve mechanical systems for a low- carbon future.