Guardian: For the first time in my life, one of my favourite London walks has become the bucolic idyll it always should have been. I’m walking down Syon Vista in Kew Gardens on a lovely spring morning amid flowering magnolias, snake’s head fritillaries and, unless I mistake my guess, Chinese witch hazel. The grass is still dewy, but I lie on my back and look up. The sky is filled with good news. One of the world’s busiest flight paths, that normally sullies Kew and much of west London with howling jet …