 French volunteers are using a pioneering Japanese tree-planting method to create pocket forests in Paris in the hope they will slow climate change, create biodiversity hotspots and tackle the growing number of heatwaves in the capital.On a damp Saturday afternoon in a southern suburb of Paris, a young boy of 9 wields a spade to plant a sapling on an abandoned strip of land.He isnt that much taller than the young tree he is planting. The afternoon rain has churned the ground beneath him into mud... 