Coastal Hazards and the Global Distribution of Human Population

¹ Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964
² Center for Climate Systems Research, Columbia University and Goddard Institute for Space Studies, National Aeronautics and Space Administration, 2880 Broadway, New York, NY 10025
³ Rockefeller University and Columbia Earth Institute and School of International and Public Affairs, 1230 York Ave., Box 20, New York, NY 10021-6399

Dr. Small is an associate research scientist and lecturer at the Lamont Doherty Earth Observatory of Columbia University. He holds a Ph.D. in Earth Sciences (geophysics) from the Scripps Institution of Oceanography, University of California-;San Diego as well as degrees from the University of Texas at Austin and the University of Wisconsin-;Madison. His research interests focus on the evolution and structure of ocean basins and on applications of remote sensing to studies of continental physiography and population distribution.

Vivien Gornitz received her Ph.D. in Geology from Columbia University in 1969. As a Research Scientist at Goddard Institute for Space Studies and Columbia, she investigates historic sea level trends and impacts of future sea level rise on the coastal zone.

Joel E. Cohen is Abby Rockefeller Mauzé Professor of Populations at Rockefeller University and Professor of Populations at Columbia University in New York City. In 1999, Cohen was co-winner of the Tyler World Prize for Environmental Achievement. In 1997, he won the first Olivia Schieffelin Nordberg Prize given by the Population Council "for excellence in writing in the population sciences." The prize was given for his book, How Many People Can the Earth Support? (W. W. Norton, 1995). Cohen is an elected member of the American Academy of Arts and Sciences, the American Philosophical Society, and the U.S. National Academy of Sciences.

ABSTRACT

A frequently predicted consequence of global climate change is an increased effect of coastal hazards on the world's human population. The impact of coastal hazards depends on the proximity of human population to the coastal zone. Recently compiled population estimates are combined with a new continental digital elevation model in an attempt to quantify the global distribution of human population and occupied land area with respect to elevation and coastal proximity. The limited spatial resolution of the census data allows one to quantify some of the uncertainty in the spatial distribution of population. This provides a lower bound on the uncertainty in the resulting distributions but does not account for uncertainty in the census data or elevation data. Long-term records of relative sea level rise, tidal heights, and storm surge heights can be combined with global sea level rise estimates for a variety of climate change scenarios to estimate the approximate magnitude of vertical changes in local sea level. It is verified that large numbers of people live at low elevations near coasts but the uncertainties are too large to provide meaningful estimates of the number of people who reside in so-called "coastal zones" worldwide. The principal conclusion is that both the spatial distribution and the resolution of global data must be significantly improved before realistic quantitative assessments of the global impact of coastal hazards can be made.