'If you think you've got the green belt forever, say goodbye to it'

"What they want to do here is a warning to anyone else: if you think you have got green belt and you think it will be there forever, say goodbye to it." Fleur Albrecht is protesting against a huge development on land near to her home. She is passionate and angry. In a yellowing wheat field, next to an oak tree, we are standing on the front line of huge changes to London's green belt. This is 85 acres of green belt on the edge of London between Potters Bar and the South Mimms service station. It is criss-crossed by footpaths and looks like it is used a lot. This is where a Europe's largest cloud and AI data centre will be built, the aim to provide jobs and economic growth. Ms Albrecht says the data centre will devastate the green belt here. "This is the lungs of London. We are so lucky to have this open green space," she tells BBC London. "My house is 75 metres away from massive big sheds that they want to build on this green belt. "It's going to affect the enjoyment of coming out here. It's a massive amount of sky, birdsong, see the seasons change - all of that will be gone." A group of residents against the data centre are by the an tree. They have tied ribbons to it and posters. Carmen Rampersad lives locally. "I'm completely against it," she says. "One of the biggest worries I have is the consultation process. It hasn't been transparent, it hasn't been open and the vast majority of the people in this community are just finding out that this is happening after it has been approved. "There's a school 400 metres away from where the boundary will be and I think those children have a voice. "From the information that I do know about data centres, I do know they use incredible amounts of resources for their cooling systems, be it water or energy. I don't know where they're going to tap into that here. But environmentally I think it's going to be catastrophic." Bunty Shah is a protester who worries about the potential health impact of the project. "Potters Bar is a sleepy commuter town surrounded by the M25," she says. "What you see here is the lungs of Potters Bar. You take this away there is going to be a lot of health effects for people that live here. "There's already issues with asthma because we are surrounded by the M25 so I think it's ridiculous they want to put a data centre here on our bit of green belt that protects us from the M25." Colin Shepherd has lived in the area all his life. "It's unbelievable," he says. "Why do they want to build something like that here on premium farmland? "It's a place for people to come and walk and just enjoy the countryside and it seems terrible to cast it aside as'grey belt' when it actually isn't. I think the people of Potters Bar will be up in arms about it." London and the South East house some of Europe's biggest data centres. For example, Slough is now considered to be the largest data centre hub in Europe. These data centres are where pretty much anything on your phone or computer is stored - the cloud, websites, social media, pictures, music and more. More are on the way, particularly with the rise of artificial intelligence. According to figures from construction researchers Barbour ABI, developers are applying to build 17 data centres in London, as well as another 39 in the Home Counties. The developer dc01uk says: "Providing up to two million square feet of data centre floor area on land east of South Mimms Services, this facility will generate approximately 200 new highly skilled jobs and investment on this site, in addition to new employment opportunities during the construction phase, and significant investment value generated indirectly through the delivery of the project." It also says the land should be seen as grey belt, which the government says can be used for development. "Whilst technically designated as green belt, the land performs poorly against the purposes of the green belt, being adjacent to South Mimms Services and the M25, and benefits from being set in a valley, meaning development can come forward in a sensitive way. The site can therefore be characterised as grey belt." The developer also says it intends to also create wildlife habitats. "The proposals come with plans to deliver significant biodiversity enhancements to ensure that we exceed 10% biodiversity net gain," it said. "Our proposals are landscape-led, with over 54% of the site being retained and enhanced as open space. Hundreds of new trees will be planted on site, and three landscaped belts will surround the proposed buildings, to the north, east and south of the site." Data centres are resource-hungry and use a lot of electricity to keep the servers cool and the internet running. They also use a lot of water for cooling. In the 2022 drought, Thames Water looked at how much water data centres in the area were using. National Grid's chief executive, John Pettigrew, has previously said that the power data centres use will increase sixfold in the next decade. He said the grid was becoming "constrained" and "bold action" was needed to create a network able to cope with "dramatically" growing demand. The local Hertsmere Borough Council has given the data centre the go-ahead. The leader Jeremy Newmark is unapologetic. "It's about ensuring this borough is benefiting from the country's digital future," he told BBC London. "It's about ensuring we are playing our role in the national growth mission. It's about powering jobs, building the skills we need around here and ensuring key parts of our economy have access to high-quality bandwidth they require. "It's always going to be a balancing act. In this case we have made a judgement call and that's what leadership is about. "It's about making the choices that are right for this area. In fact my experience is the vast majority of people who have looked at this think it is the right thing as they understand that this area has a critical role to play in the new digital economy. "This is very low-performing green-belt land. In this instance, we think sacrificing a small amount of green belt is worth it."