Dramatic environmental changes now sweeping the planet, such as the loss of forests and the spread of cities are promoting conditions for a rise in new and previously suppressed infectious diseases, including malaria and bilharzias, according to the United Nations Environment Programme'sGlobal Environment Outlook Year Book 2004/2005. The climate change may aggravate the threats of infectious diseases in three ways, i.e., by increasing the temperatures under which many diseases and their carriers flourish, by further stressing and altering habitats, and by causing migrations, it further says. The Year Book links the emergence of many other old and new diseases with environmental change. Malaria, Japanese encephalitis and dengue hemorrhagic fever are transmitted to humans by mosquitoes, which thrive in standing water. Increasing level of rubbish and solid wastes in developing countries-a result of growing consumerism, poor refuse handling services, fly tipping, lack of recycling schemes and inadequate disposal sites-are aggravating the problem.