Figure 1.11
Anthropogenic acid rain damage. (A) The pH scale ranges from 0 to 14. A pH value of 7 is neutral. Values above 7 are basic, or alkaline, and values below 7 are acidic. Extremely acidic rain can have a pH value as low as 2.0, close to that of lemon juice. (B) This weathered stone lion is outside the Leeds City Hall in Leeds, in the United Kingdom. It has been dissolved by acid rain caused by the long history of burning coal in the region. (C) Anthropogenic acid rain weakened these Fraser fir (Abies fraseri) and red spruce (Picea rubens) trees in Mt. Mitchell State Park, North Carolina. Once trees are weakened by acid rain, insects can more easily attack them, causing additional forest damage.(B. © Ryan McGinnis/Alamy; C. Will & Deni Mcintyre/PhotoResearchers/Getty Images)