Dengue fever, arguably the most threatening emerging infectious disease(in terms of its prevalence and morbidity and mortality: 50 to 100 million annual cases), may have just gained a foothold in the United States. For a long time dengue has been confined to warmer, tropical regions where the mosquito vectors, A. aegypti and A. albopictus, can readily replicate the virus. However, with the world warming, dengue has come as far north as Texas recently. Dengue is poised now to spread throughout the rest of the states -- especially with poor mosquito control measures, urbanization and population growth, and air travel. An effective dengue vaccine and curbing carbon emissions in a world expected to increase energy demand ten-fold this century have never been more critical.