In Copenhagen they are debating how to end deforestation, but in Cuba's Pinar del Río they were replanting 50 years ago, creating lush, unspoilt valleysBirds and butterflies are swooping above us and, as our taxi reaches the summit of this forest road just 40 minutes from the heat and noise of Havana, the view opens to an undulating landscape painted every shade of green. Before Castro these hills were dusty yellow and brown scrub.If Copenhagen needs a model, this is the most eloquent I know, a...