By
the year 2025, more than 60% of the world’s population will live in
cities, with higher percentages expected in developed nations.
The urban growth rate in the United States, for example, is estimated
to be 12.5%, and the recent 2000 Census found that more than 80% of the
population currently lives in urban areas. Furthermore, the U.S.
population is not only growing but is tending to concentrate more in
urban areas within the environmentally sensitive coastal zones.
Urban growth creates unique and often contentious issues for
policymakers related to land use zoning, transportation planning,
agricultural production, housing and development, pollution, and
natural resources protection. Urban expansion and its associated
urban heat islands, urban aerosol concentrations, and impervious
surfaces also have measurable impacts on weather and climate
processes. The devastating and deadly Heat Wave of the mid-1990s
in Chicago and recent urban flooding in Houston are two manifestations
of how the actual city environment can influence weather and climate
processes.
This lecture will discuss various ways that cities can impact weather
and climate and also address what the future implications are for
weather forecasting, climate change assessment and prediction, water
resource management, public health, agriculture, and urban
planning. The discussion will also offer a set of recommendations
for what type of studies, observations, and models are required in the
future.