Scientists at Duke University and the University of California, Santa Barbara have identified a climate feedback loop involving widely distributed yet underappreciated microbes like plankton that could quicken the pace of climate change.  However, this discovery comes with a silver lining: a potential early warning sign that might help us brace for the tipping point. The researchers have been studying microscopic organisms called mixotrophs. These versatile organisms have two metabolic modes, allowing them to photosynthesize like plants or consume food like animals, depending on their environment. Daniel...