New Scientist: In one of the most extreme climate change scenarios, a blistering drought will dry up the Amazon forest, which will ignite and burn away, leaving the world’s rain patterns disrupted. Identifying factors that could tip the forest over the edge and make this scenario a reality is clearly a matter of great importance. Now new computer models suggest that, although the Amazon will not dry out as much as feared, humans clearing land with fire pose a huge risk as the region …