Press reports on deforestation say that *"the Amazon is the main victim, losing 42,510,000,000 m2 of forest cover each year, or 1,350 m2 every second—the area of one football pitch every seven seconds". Elsewhere, we read that "every day in Switzerland, an area equivalent to eight football pitches is built on". Or that certain plots "cover an area of 3.9 square kilometres (about five hundred football pitches)"*. The conversions seem highly fanciful, but what is the real story? The dimensions of the stage on which Mbappé and his fellow players perform range from 90 to 120 m in length and from 45 to 90 m in width. Without any further details, that gives an area of between 4,050 m2 and 10,800 m2. Quite a difference! Pitches used for international matches must measure 105 m × 68 m, giving an area of 7,020 m2. Not quite at home with this new unit? Never fear: converters are available online (for example, **convertworld.com/fr/superficie/km2.html** )…