‘Whole life carbon emissions’ are both the operational and the embodied emissions considered together over the life of the building. A key point is that considering operational or embodied emissions in isolation can lead to poor decision-making with unintended consequences. Embodied emissions are therefore a holistic assessment of the carbon emissions resulting from manipulating material from its original source via its use by society to its ultimate disposal. The simple definition of whole life carbon is the total sum of the operational and embodied emissions expended over a building’s whole life. Carbon emissions from the creation of the built environment derive principally from energy used in the construction process. Sourcing materials, constructing, repairing and maintaining buildings are also responsible for significant energy use – this is referred to as ‘embodied energy’, giving rise to the term ‘embodied carbon emissions’. Trees capture carbon dioxide over a natural lifespan before they die and rot away.