The Southwest's year of record-breaking heat, drought, and catastrophic fire may be a harbinger of worse to come for the region. Depending on whom you ask, maybe much worse. In yesterday's radio broadcast of On Point, experts from a variety of fields laid out scenarios for cities like Phoenix and Las Vegas that range from severe restrictions on personal water use (no more irrigated lawns or private pools) to mass out-migration driven by "mega-droughts." --b.d.s.