Building activities have shown a spurt. As per the Botany Department, Osmania University the mean maximum temperature of Hyderabad city rose by four degrees celsius from 250C in the 1960's to 290C in the 1990s. This effect is a direct result of the increase in air pollution, as well as in builtup areas. High densities and shortage of greenery and open spaces have vastly contributed to this rise in temperature.