| Country | Environment - current issues |
| South Africa | lack of important arterial rivers or lakes requires extensive water conservation and control measures; growth in water usage outpacing supply; pollution of rivers from agricultural runoff and urban discharge; air pollution resulting in acid rain; soil erosion; desertification |
| South Georgia and the South Sandwich Islands | NA |
| Southern Ocean | increased solar ultraviolet radiation resulting from the Antarctic ozone hole in recent years, reducing marine primary productivity (phytoplankton) by as much as 15% and damaging the DNA of some fish; illegal, unreported, and unregulated fishing in recent years, especially the landing of an estimated five to six times more Patagonian toothfish than the regulated fishery, which is likely to affect the sustainability of the stock; large amount of incidental mortality of seabirds resulting from long-line fishing for toothfish note: the now-protected fur seal population is making a strong comeback after severe overexploitation in the 18th and 19th centuries |
| Spain | pollution of the Mediterranean Sea from raw sewage and effluents from the offshore production of oil and gas; water quality and quantity nationwide; air pollution; deforestation; desertification |
| Spratly Islands | NA |
| Sri Lanka | deforestation; soil erosion; wildlife populations threatened by poaching and urbanization; coastal degradation from mining activities and increased pollution; freshwater resources being polluted by industrial wastes and sewage runoff; waste disposal; air pollution in Colombo |
| Sudan | inadequate supplies of potable water; wildlife populations threatened by excessive hunting; soil erosion; desertification; periodic drought |
| Suriname | deforestation as timber is cut for export; pollution of inland waterways by small-scale mining activities |
| Svalbard | NA |
| Swaziland | limited supplies of potable water; wildlife populations being depleted because of excessive hunting; overgrazing; soil degradation; soil erosion |
| Sweden | acid rain damage to soils and lakes; pollution of the North Sea and the Baltic Sea |
| Switzerland | air pollution from vehicle emissions and open-air burning; acid rain; water pollution from increased use of agricultural fertilizers; loss of biodiversity |
| Syria | deforestation; overgrazing; soil erosion; desertification; water pollution from raw sewage and petroleum refining wastes; inadequate potable water |
| Taiwan | air pollution; water pollution from industrial emissions, raw sewage; contamination of drinking water supplies; trade in endangered species; low-level radioactive waste disposal |
| Tajikistan | inadequate sanitation facilities; increasing levels of soil salinity; industrial pollution; excessive pesticides |
| Tanzania | soil degradation; deforestation; desertification; destruction of coral reefs threatens marine habitats; recent droughts affected marginal agriculture; wildlife threatened by illegal hunting and trade, especially for ivory |
| Thailand | air pollution from vehicle emissions; water pollution from organic and factory wastes; deforestation; soil erosion; wildlife populations threatened by illegal hunting |
| Timor-Leste | widespread use of slash and burn agriculture has led to deforestation and soil erosion |
| Togo | deforestation attributable to slash-and-burn agriculture and the use of wood for fuel; water pollution presents health hazards and hinders the fishing industry; air pollution increasing in urban areas |
| Tokelau | limited natural resources and overcrowding are contributing to emigration to New Zealand |
| Tonga | deforestation results as more and more land is being cleared for agriculture and settlement; some damage to coral reefs from starfish and indiscriminate coral and shell collectors; overhunting threatens native sea turtle populations |
| Trinidad and Tobago | water pollution from agricultural chemicals, industrial wastes, and raw sewage; oil pollution of beaches; deforestation; soil erosion |
| Tunisia | toxic and hazardous waste disposal is ineffective and poses health risks; water pollution from raw sewage; limited natural fresh water resources; deforestation; overgrazing; soil erosion; desertification |
| Turkey | water pollution from dumping of chemicals and detergents; air pollution, particularly in urban areas; deforestation; concern for oil spills from increasing Bosporus ship traffic |
| Turkmenistan | contamination of soil and groundwater with agricultural chemicals, pesticides; salination, water logging of soil due to poor irrigation methods; Caspian Sea pollution; diversion of a large share of the flow of the Amu Darya into irrigation contributes to that river's inability to replenish the Aral Sea; desertification |
| Turks and Caicos Islands | limited natural fresh water resources, private cisterns collect rainwater |