Along the low-lying beachfront of the city of Abu Dhabi stands a skyline punctuated with high-rise towers, beach clubs, restaurants, and cafes. As with many of the world's leading cities, much of Abu Dhabi's development sits at just above sea level, making the question of rising global seas a matter of critical self-interest for the city.
According to the World Bank, nearly one half of the world's population lives in coastal environments, many of which would be impacted by changes in coastal sea levels as ocean temperatures warm and ice sheets near Greenland and Antarctica melt. This is a very real concern; over the last century, the global sea level has risen by approximately 30 centimeters and the atmosphere has warmed by approximately one degree Centigrade, according to a report by the Intergovernmental Panel on Climate Change. Yet for all of the potential consequence on urban developments across the world — most of which were planned within the context of present-day sea levels — credible projections on future sea-level change are not currently available.
David Holland, professor of Mathematics at NYU New York's Center for Atmosphere Ocean Science (CAOS) and principal investigator of the Project on Global Sea-level Change at NYU Abu Dhabi, aims to change this.
"The behavior of the climate system on our planet is far more complex than I had ever imagined," he said. "Only through observation of the natural system, coupled with theoretical developments implanted in computer models, can we come to an understanding and projective capability of sea- level change."
The complexity of such projective modeling stems from the range of causes for climate change — natural variation and forced (human-caused) variation. Separating these two factors as they impact the environment simultaneously will require a significant amount of data and resources, Holland said.
Breaking down this problem requires an understanding of the chain of events that impact sea-level change, he explained. "The ice is affected by the ocean temperature, and ocean temperature is affected by the atmosphere. The question really is, 'why does the atmosphere change?' It changes because of natural variation, greenhouse gases, ozone changes, and unanticipated natural causes such as volcanoes — and all of these signals are progressing in an interrelated pattern."
The Project on Global Sea-level Change team has already started to make strides in contributing to the record of reliable observational data through field research in the Ilulissat and Helheim ice fjords in Greenland, where a team of nine deployed three times over the course of 12 weeks in 2012. Holland was joined by Logistical Coordinator of Research and Project Leader at NYUAD Denise Holland (also his wife), one postdoctoral fellow from NYUAD, one postdoctoral fellow from NYUNY's CAOS, and four NYUNY graduate students.
During its expeditions, the team positioned a range of meteorological, glaciological, and oceanographic monitoring devices to record several types of metrics that relate to the two principal causes of rising sea levels: glacial melting and changing ocean temperatures due to atmospheric warming. These two factors are "the lynchpins upon which future global sea level rests," according to Holland.