Air and water pollution are significant environmental problems especially in Portugal's urban centers. Industrial pollutants include nitrous oxide,sulfur dioxides, and carbon emissions. In 1996, industrial carbon dioxide emissions totaled 47.9 million metric tons. The nation's water supply, especially in coastal areas, is threatened by pollutants from the oil and cellulose industries. Portugal has 37 cubic kilometers of renewable water, of which 53% is used to support farming and 40% is for industrial activity. In total, the nation's cities produce an average of 2.6 million tons of solid waste. The nation's wildlife and agricultural activities are threatened by erosion and desertification of the land.
Although erosion is a natural process human land use policies also have had an effect on erosion, especially industrial agriculture, deforestation, and urban sprawl. Land that is used for industrial agriculture generally experiences a significantly greater rate of erosion than that of land under natural vegetation, or land used for sustainable agricultural practices.The rate of erosion depends on many factors. Climatic factors include the amount and intensity of precipitation, the average temperature, as well as the typical temperature range, and seasonality, the wind speed, storm frequency. Erosion is caused by “fluid flow”. Any substance, like wind, water, or ice, which flows consistently from one place to another, will facilitate erosion.