Associated Press: Argentina’s Perito Moreno glacier is one of only a few ice fields worldwide that have withstood rising global temperatures. Nourished by Andean snowmelt, the glacier constantly grows even as it spawns icebergs the size of apartment buildings into a frigid lake, maintaining a nearly perfect equilibrium since measurements began more than a century ago. “We’re not sure why this happens,” said Andres Rivera, a glacialist with the Center for Scientific Studies in Valdivia, Chile. …