Scientists converge in La Jolla to discuss rising sea levels

Editor’s note:

This report is the first in a two-part series chronicling an international workshop on sea-level rise, held at UC San Diego last week. Leading climate scientists and public-policy experts shared research findings and formulated strategies to combat and adapt to projected short- and long- term rises in sea level. Part 2, to be published in the Sept. 27 issue, examines the measures coastal cities around the world are already adopting.

By Lynne Friedmann

Sea level is on the rise and demands the attention of policymakers and urban planners to identify and set in motion specific, achievable actions over the next several years to mitigate or adapt to a rise in sea level over the next 300 years of between 2.4 and 5 meters (8 and 16 feet), based on current understanding and circumstances.

This was the message of the International Workshop on Coastal Cities, Climate Change, and Sea-Level Rise, held Sept. 5-7, on the UC San Diego campus where representatives from 18 leading research institutes — members of the Association of Pacific Rim Universities (APRU) and a number of non-government organiza- tions — explored ways of improving cooperation among academics, government officials, and policymakers to protect human lives and economic resources.

It is not often that an issue brings together climate scientists, economists, architects, urban planners, political scientists, and international relations experts. But, that’s exactly who was in the room, motivated to find solutions to the potentially catastrophic effects of sea-level rise on 200 million people and trillions of dollars of coastal assets ($100 billion alone in California).

The first day of the meet- ing provided clear and co- herent presentations of the latest research outcomes on climate change at different locations around the world.

“The conclusion is that climate change and local sea-level rise is highly variable,” said Jim Falk, Honorary Professorial Fellow in the University of Melbourne (Australia) School of Land and Environment and director of climate change research for APRU. “This calls for needs assessment city by city, region by region.”

Jeff Severinghaus, professor of geosciences at Scripps Institution of Oceanography (SIO) at UCSD, said, “The Earth is like a waterbed, when you ‘step’ on it in one place, it rises in another.”

Accounting for sea-level rise differences are factors such as wave and storm surge, El Niño climate patterns, topography, land subsidence, or a rise in land elevation (as can occur in highly seismic areas of California).

Much focus in recent years has been on the contribution of melting polar ice to sea-level rise.

“Melting itself is not a climate change (affect),” said Helen Fricker, professor, Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics, at SIO. “Melting of ice is normal.” The problem is that current ice melting is faster than has occurred historically.

When the margins of ice shelves thin, glaciers behind them respond to gravity and are pulled to the sea. Most ice-shelf thinning is related to warm ocean currents. But it’s only been recently that melting ice has made a contribution to rising sea- level rise.

“In the past 50 years, rising sea-level rise has been due to warmer oceans,” said David W. Pierce, a programmer analyst in the SIO Division of Climate, Atmospheric Science and Physical Oceanography.

“Like most fluids, seawater expands when it becomes warmer, contributing to an increase in sea level,” Pierce said. This warming effect, alone, is estimated to be responsible for more than half of the current rate of sea-level rise observed by researchers.

The stakes are high when it comes to instituting mitigation or adaptation policy relative to sea-level rise. More than half the world’s largest cities are coastal ports. Of these, more than 130 port cities are at increasing risk from severe storm-surge flooding, damage from high storm winds, rising and warming global seas, and local land subsidence, according to a study by the Organization of Economic Cooperation and Development.

“Forty-nine of these cities are on the Pacific Rim,” said Trevor Davies, Pro-Vice-Chancellor, University of East Anglia (UK), and director of the Fudan Tyndall Center, Fudan University (China). “Of the top 20 cities identified, Asia has the largest overall exposure.”

Workshop sponsors were the Association of Pacific Rim Universities (APRU), whose aim is to foster cooperation in education research, and enterprise thereby contributing to the economic, scientific, and cultural advancement in the Pacific Rim; USC Marshall School of Business Administration, and the Sustainability Solutions Institute (UCSD).

“University presidents shape the research focus at their institutions,” said workshop organizer David Woodruff, director of the Sustainability Solutions Institute (UCSD). Therefore, a major goal of the gathering is how to motivate universities to leverage action against climate change and its effects.

“There will be big changes in the next 300 years, but we only have 30 years to plan and mitigate,” said Woodruff. “Governments should plan for 100 years of inevitable sea- level rise, even if greenhouse gas levels are reduced.”

■ ‘Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future,’ National Research Council, 2012:

■ ‘Top 20 Cities with Billions at Risk from Climate Change,’ Bloomberg Business Week, July 5, 2012: