The land ranges from mountainous to gently rolling, with fertile river valleys. It has a moderate subtropical climate, ample rainfall, and fertile soils. Periodic hurricanes can cause extensive damage. The majority of the population is of mixed African and European descent. Spanish is the official language, and Roman Catholicism the predominant religion. Population growth is a continuing problem in the Dominican Republic, and emigration to the United States, particularly to New York City, has been high. There are large numbers of Haitian migrants in the Dominican Republic as well as a significant population of native-born inhabitants who are of Haitian descent; a constitutional court decision in 2013 declared all inhabitants of non-Dominican descent born in the country after 1929 to be noncitizens.