ABSTRACT
Only one-fifth of the planet is still covered with sustainable forests, stated the report, and few of those are protected by governments. Although the destruction of the forest throws the whole system out of balance, deforestation is speeding up. Throughout North America, wetlands have acted as erosion control barriers and provided homes for fish and amphibians and resting grounds for migrating birds. They are an essential part of the habitat of 95 percent of all commercially harvested fish on the continent and a sanctuary for over half its endangered bird species. Three-quarters of Poland's rivers are so contaminated by chemicals, sewage, and agricultural runoff that their water is unfit even for industrial use. The Great Lakes are also losing water, partly because of groundwater mining. Leaky gasoline tanks and municipal sewage lagoons, municipal landfills, feedlot effluent, mine tailings, septic tank ruptures, oil spills, pesticide runoff, and even road salt are all sources of groundwater pollutants.
