Big Threat to Amazon: Unseen Forest Fires

Someone flying above the Amazon in a plane would see nothing amiss, but scores of small, slow-moving fires beneath the canopy of trees are destroying more land than deforestation, reports LiveScience. New satellite imaging from NASA has revealed these so-called "understory fires." Flames are only a few feet high, and the fires themselves move only a few feet per minute, but they can last several weeks, reports Nature World News.

The culprit? Careless humans, apparently. These fires generally occur near populated areas, and they're often set off by campfires or discarded cigarettes—aided and abetted by low humidity. NASA researchers say the discovery of the fires will affect climate models. "We don't yet have a robust estimate of what the net carbon emissions are from understory fires, but widespread damages suggest that they are important source of emissions that we need to consider," says one. (More Amazon rainforest stories.)