National Geographic: Intense fires have the power to generate dirty thunderclouds that may be influencing the climate, scientists have discovered. Like volcanoes, the dirty, fire-induced thunderstorms, or pyrocumulonimbus storms (pyroCbs), can funnel smoke and particulates high into the stratosphere, experts announced Friday at an American Geophysical Union meeting in Foz do Iguaçu, Brazil. The high-flying smoke palls created by the so-called pyrocumulonimbus storms (pyroCbs) may be having unknown …