As a Society we are faced with the constant challenge of improving quality of life and economic prosperity, which correlates often with energy production, while at the same time minimising the impact of our activities on the environment. The UK, with the 2008 Climate Change Act, has set a legally binding target of reducing emissions of greenhouse gases by 80% by 2050. The talk will consider energy production for all applications – electricity; manufacturing & chemical industry; transport and heating. This will show that only part of the challenge of reducing carbon emissions to sustainable levels can be met through the efficient use of energy through exergy analysis, an approach that was for the first time applied to chemical processes by Kenneth Denbigh – the first Chemical Engineering Professor in Edinburgh. For several types of emissions, to go beyond energy efficiency, the only possible approach is given by carbon capture and storage, an obvious example being the production of cement. Examples taken from research carried out in the School of Engineering will be used to show possible approaches for decarbonising our economy and the talk will conclude with a short discussion of the challenges of removing carbon dioxide directly from the atmosphere, something that may be needed if we are to meet the commitments set by the 2015 United Nations Climate Change Conference (COP21) in Paris.