SUSTAINABILITY SPOTLIGHT | 27 The study explores ways to decarbonise • Support, including from policy mechanisms, is controlled environment agriculture (CEA), so required for CEA to move forwards in a low-carbon that growers can supply high-quality locally manner. This presents a signi昀椀cant opportunity for produced food to the British market in the UK and can have a positive impact on both local and national economies. environmentally and 昀椀nancially sustainable • Measures and incentive mechanisms should be put in ways. It also provides robust 昀椀ndings to place now to facilitate the long investment horizons inform investments in CEA and the associated of CEA, typically 20–50 years. Current investments technologies and infrastructure, highlighting will impact the state of food production in 2050. that the right solutions can help CEA to Decline in numbers of CEA operations contribute to greater food security and the UK’s net-zero goal. Because of recent higher energy costs, in 2022 production from the sector reached its lowest level British agriculture comprises both traditional water since recordings began 30 years ago. But because intensive growing methods in open 昀椀elds and horticultural CEA has so many potential bene昀椀ts – among them the operations such as controlled environment agriculture ability to boost British food security and a昀昀ordability (CEA), some of which are highly energy- and carbon- – Defra recently commissioned a study on the gains, intensive. The scope of the Defra study was to explore costs, feasibility and scalability of current and future the potential to improve the sustainability credentials and industrial horticulture models. The work was carried feasibility of the latter. out by Dr Diana Khripko and Dr Samuel Short from IfM Engage, and Dr Bernhard Strauss and Dr Pantea Lot昀椀an CEA is an umbrella term covering several di昀昀erent from Camrosh. The report was published in December horticultural sub-sectors characterised by their separation 2023. of crops from the natural environment, and the ability to “Defra’s agri-food evidence programme supports the control parameters like temperature, humidity, carbon productivity, environmental sustainability, development dioxide concentrations, nutrients and light. Glasshouses of strategies to address the risks and trade-o昀昀s of and polythene tunnels are the most well-known examples, farming systems. This study was commissioned to but other types of set-ups, such as indoor and vertical provide context around opportunities and barriers farms, are emerging. to the sustainable growth and development of the CEA is high-yielding, water- and land-use e昀케cient, horticulture sector. Whilst it is clear from the report and historically allowed for cheap food production. But that there is no silver bullet, the information and data under the given geographical and climate conditions, collated and disseminated will be of great use as the the operations have a considerable energy demand and sector looks to further decarbonise, whilst facilitating an additional need for carbon dioxide. Currently in the resilience and productivity opportunities.” (Statement UK the sector predominantly runs on natural gas-based from Defra, 2023). technologies. Carbon-intensive infrastructure The 昀椀ndings suggest that CEA can contribute to greater The CEA sector has a considerable carbon footprint for food security, food a昀昀ordability and the net-zero goal its size, but the technologies it builds on do not when the following recommendations are considered: inherently yield high emissions. Over the last couple of decades, growers in CEA have overwhelmingly • Energy-e昀케ciency measures should be encouraged relied on combined heat and power (CHP) generation throughout the sector, with a focus on integrating low/ in line with established policy. CHP is an energy- zero-carbon energy supply systems into new CEA e昀케cient technology that even allows many growers builds. The necessary clean energy technologies and additional revenues from selling excess electricity to the solutions already exist and are largely proven. national grid. But deployed CHP are currently primarily fuelled by natural gas. It is also a common practice to enrich the atmosphere in the growing operations with carbon dioxide to boost photosynthesis. While