Fires Main Threat To Amazon In Drier Climate - Study NORWAY: April 8, 2008 OSLO - Fires set by people will be the biggest threat to the Amazon rainforest in coming decades linked to a drier climate caused by global warming, researchers said on Monday. They said swathes of the forest were more likely to be killed by blazes raging out of control than by a more gradual shift towards savannah caused by more frequent droughts predicted by the UN Climate Panel in a 2007 report.