As well as sea level rises, other global warming effects such as shifts in monsoon systems and severe and persistent droughts have to be factored into the number of environmental refugees to be expected. A temperature rise of only one degree C, which is expected by the year 2050, could affect monsoon patterns and add to the drought problems. The Indian subcontinent, projected to hold 2.1 billion people by 2050, relies on monsoons for 70 percent of its rainfall. The entire Asian-Pacific region is dependent on monsoon rains. Areas susceptible to the effects of severe drought are northern Mexico, northern Chile, northeastern Brazil, eastern Argentina, the Mediterranean basin, the Sahel, the southern quarter of Africa, and sectors of the middle and tropical latitudes of Asia, as well as parts of the United States, southern Canada, southern Europe, and Australia. These latter four areas produce most of the surplus food that sustains more than 100 Third World nations at present.

A report by Almendares, Sierra, Anderson and Epstein (1993) showed how environmental changes may affect the incidence of different vector-borne diseases in Honduras. A vector-borne disease is spread or transmitted from one host to another by a carrier such as an insect. Overgrazing and deforestation have significantly changed the landscape in parts of Honduras. Forests play a role in the global warming process because tropical rainforests provide a sink for carbon dioxide, which is turned into plant bodies, which in turn helps regulate the Earth=s temperature (Benyus, 1995). Temperatures have increased and rain patterns have changed, too, in Honduras (Almendares, Sierra, Anderson and Epstein, 1993). Warmer ambient temperatures have decreased the incidence of malaria in southern Honduras, but its incidence has increased in the north as more nonimmune individuals have migrated from the south