The economic development plans for 1979–82 and 1983–86 were financed chiefly by the United Kingdom and supplemented by Australia, New Zealand, and Japan, with loans from the Asian Development Bank. Canada, Germany, and the Republic of Korea also have started small aid programs. The government lays out National Development Plans at four year intervals, and is now on its seventh plan, for 2000–04. The goals are set with expertise assistance from Australia, the United Kingdom, New Zealand, and international financial organizations, the country's primary sources of aid. The current National Development Plan sets priority on the development of fisheries and air transportation, including a proposal for a government airline. Other sectors emphasized are communications, agriculture and tourism. Policies are aimed at improving education and training, increasing government revenues, increasing employment opportunities and narrowing the trade deficit. It has been made illegal to sell land in Kiribati, but it may be leased. Concern about preserving traditional culture and the environment, and preventing the formation of a landless class, are as strong as aspirations for economic growth and participation in the cash economy. Of particular concern in this group of low-lying atolls is the effects of global warming, as a significant rise in the sea level could literally make much of the country disappear.