On Significant Figures, Peter Gleick explains that growing populations worldwide have exerted peak pressures on water supplies, leaving entire regions more vulnerable to natural variations in rainfall. In turn, global warming has made these natural variations more extreme. One such variation is El Niño, when "droughts are typically more widespread and severe." Dr. Gleick reports on the challenges faced around the world in 2016, as several historic droughts grow worse. Meanwhile, in honor of Earth Day, Ethan Siegel suggests we count our blessings: "there’s still no planet as friendly to life or hospitable to humans as Earth. It’s the fact that we went beyond the Earth and discovered the Universe that’s allowed us to appreciate just how rare, precious and special our home world is."