Tropical Asia refers to the entirety of the areas in Asia with a tropical climate. These areas are of geographic and economic importance due to their natural resources and biodiversity, which include many species of agricultural value.[1][2] There are 16 countries in tropical Asia, ranging in size from around 610 square kilometres (240 square miles) (Singapore) to 3,000,000 km2 (1,200,000 sq mi) (India).[2] The total population as of 2006 was 1.6 billion, predominantly rural, and projected to reach 2.4 billion by 2025.[1][2] Climate in tropical Asia is subject to seasonal weather patterns with the two monsoons and the amount of tropical cyclones in the three core areas of cyclogenesis (the Bay of Bengal, north Pacific Ocean and South China Sea). Stressors on the environment include growing urbanization, land industrialization, economic development, land degradation, environmental issues, and increased pollution, all of which are contributing to changes in climate.[1][2]