By by Roberta Harrington in Los Angeles The Amazon rainforest could face “large-scale collapse” by 2050, says new research. This would be included in a tipping point that the ecosystem encounters because of unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts, says a new and comprehensive article in the journal Nature. For 65mn years, Amazonian forests remained relatively resilient to climatic variability, but long-existing feedbacks between the forest and environmental conditions are being replaced by novel feedbacks that …