| Our first step to figuring out the answer was to talk with the brilliant numbers whiz Pamela Duncan, editor of the Guardian data projects team. “Hmmm,” she said. “Maybe.” Pamela went away and talked to Zeke Hunter-Green, who works on digital investigations. Some time passed, and then: “Theoretically, we can do this”. There was a long list reasons it would be complicated and difficult, but you don’t need to know any of those because Pamela and Zeke managed to surmount every single one of them. Reader, we did it. It was, indeed, complicated and difficult. It also, at the time, felt a bit quixotic. After all, we already know independent schools often have large, lovely grounds surrounding them. Wouldn’t this be a case of stating the obvious? Two things drove our team through the next few months of detailed and painstaking research. Firstly, it turned out that no one had ever measured this before. To journalists, being told that no one knows something is irresistible. We all needed to know just how much land these schools owned (we ended up just focusing on the very top schools, the 250-odd members of the Heads’ Conference, which includes Eton, Winchester, Westminster, Radley and more). It turned out that between them, these schools owned 38,000 acres of land, a breathtakingly large area (about 19,000 football pitches, to use the traditional comparison). It also turned out that the average student at one of England’s top private schools has access to approximately 322 sq metres of green space, whereas the average state school student has access to about 32 sq metres of green space: a ratio of 10:1. That seemed like a disparity worth reporting. But the other thing that motivated us was the urge to pin down something intangible – to measure a kind of inequality that is really impossible to quantify; the human need for green space, and how it gets shared out. Over the past couple of decades scientists have been trying to pin down why green space is so good for us – and exactly how good it is. After the famous 1984 study of patients recovering from surgery which found that the ones looking out at trees recovered on average a full day sooner than those looking at a brick wall, more and more have followed. In the past few years they’ve also been looking at how green space works on young minds; education correspondent Sally Weale has summarised some of the work in her analysis. So what does it mean for young minds when your school is surrounded with prefab buildings and crumbling RAAC concrete – as opposed to rolling green fields and woods? Many English state schools do have green space, but we’ve had years of the Conservatives (and to a lesser extent Labour) selling off playing fields and then dropping a requirement that a secondary school with more than 600 pupils needed 35,000 sq metres of playing fields (58 sq metres for each child). Harriet Grant and Andrew Gregory talked to teachers, union leaders, academics and doctors about their anxieties about what was happening in our state schools and found an intricate web of connections between the shrinking space and time for play and green space for our children, and concerns about mental health and the obesity epidemic in young people. There is no doubt these issues are linked. And the private schools absolutely know this; they all talk extensively about the life outside the classroom being as important for their students as the life inside. Rugby school, for example, describes its educational model as one where “all the facets of life – academic and artistic, spiritual and sporting – form part of an indivisible whole”. Lovely for all those lucky students at independent schools who will go on, if the trend continues, to dominate our sports and politics and judiciary. But what about the rest of the children – the other 93%? Read more: | 