Despite fundamental efficiency improvements in energy devices and industrial processes, global annual energy demand and greenhouse gas emissions keep growing. Climate change mitigation remains thus one of the main challenges of engineering practice, for which a systems approach is required to account for the complex networks of energy and material transformations to supply consumers’ needs. In this talk, I will discuss the trade-offs of alternative interventions in cars and buildings, since these account for most fuel combustion emissions. These trade-offs enable the prioritisation of technology deployment in these sectors to enhance their mitigating potential. The results also show that new technologies in cars and buildings cannot be deployed at a fast-enough pace to meet current emissions targets, unless there is a reduction in the demand for the utilisation of these goods. This reduction would likely require profound changes in social organisation and urban planning.