supplies of potable water. Air and water pollution affects the country, as well as deforestation, and radiation contamination in the northeast from the 1986 accident at the Chernobyl Nuclear Power Plant. Climate Ukraine has a mostly temperate climate, except for the southern coast of Crimea which has a subtropical climate. The climate is influenced by moderately warm, humid air from the Atlantic Ocean. Average annual temperatures range from in the north, to in the south. Precipitation is highest in the west and north and lowest in the east and southeast. Western Ukraine, particularly in the Carpathian Mountains, receives around of precipitation annually, while Crimea and the coastal areas of the Black Sea receive around . Water availability from the major river basins is expected to decrease due to climate change, especially in summer. This poses risks to the agricultural sector. The negative impacts of climate change on agriculture are mostly felt in the south of the country, which has a steppe climate. In the north, some crops may be able to benefit from a longer growing season. The World Bank has stated that Ukraine is highly vulnerable to climate change. Biodiversity Ukraine contains six terrestrial ecoregions: Central European mixed forests, Crimean Submediterranean forest complex, East European forest steppe, Pannonian mixed forests, Carpathian montane conifer forests, and Pontic steppe. There is somewhat more coniferous than deciduous forest. The most densely forested area is Polisia in the northwest, with pine, oak, and birch. There are 45,000 species of animal, with approximately 385 endangered species listed in the Red Data Book of Ukraine. Internationally important wetlands cover over , with the Danube Delta being important for conservation. Urban areas Ukraine has 457 cities, of which 176 are designated as oblast-class, 279 as smaller -class cities, and two as special legal status cities. There are also 886 urban-type settlements and 28,552 villages. Politics Ukraine is a republic under a semi-presidential system with separate legislative, executive, and judicial branches. Constitution The Constitution of Ukraine was adopted and ratified at the 5th session of the Verkhovna Rada, the parliament of Ukraine, on 28 June 1996. The constitution was passed with 315 ayes out of 450 votes possible (300 ayes minimum). All other laws and other normative legal acts of Ukraine must conform to the constitution. The right to amend the constitution through a special legislative procedure is vested exclusively in the parliament. The only body that