Puget Sound may rise six inches by 2050 in some scenarios

The Daily of the University of Washington: Researchers from the UW’s Pacific Northwest Climate Impacts Group (CIG) and the Washington State Department of Ecology estimate the region’s sea levels will rise 6 inches by 2050 and 14 inches by 2100. Both Philip Mote, a CIG scientist, and Spencer Reeder, a policy strategist from the Washington State Department of Ecology, maintain these numbers as valid estimates. “These aren’t predictions but estimates based on the current science,” Reeder said.

One of the purposes of the research is to provide a risk assessment of the area to local businesses and private homeowners who could have plans for construction on the coast, he said. “You don’t want to plan for the best case; you want to plan for the worst case,” Reeder said.

The estimates are the most probable of three estimates provided for the Puget Sound. In the worst-case scenario, the Sound may even have a sea-level rise of 22 inches by 2050, although that scenario is unlikely.

The CIG has discovered the critical role of vertical land motion in the rise or fall of sea level. The movement of active tectonic plates affects Washington state because of its geographic location. The Olympic Peninsula, for example, is rising faster than sea level is, so the sea level may actually drop in that region. Other factors contributing to the Sound’s sea-level rise are the melting edges of Antarctica and Greenland. Changes in winds and storms in the Northwest region are another factor.

“The largest contributor is really the thermal expansion, followed by the melting ice,” Reeder said. Thermal expansion is the expansion of the ocean due to increased absorption of heat energy. Even if warming was to stop entirely tomorrow, the oceans would continue to expand for decades, Reeder said. “Sea-level rise is most likely to continue on from global warming,” he said.

However, Reeder and Mote remain optimistic. Mote sees the changes as an economic opportunity for suppliers of energy-efficient products. “It is a burgeoning market for these products,” Mote said in regard to solar power, wind power and other renewable energy sources. For Reeder, the concern really depends on the community. Communities close to the high tide level should be more nervous about sea level than those living away from the coast.

Weather patterns are also critical. “On a calm day with no winds and no storms, 6 inches won’t make that much of a difference, [but with a storm] the 6 inches might make all the difference in the world,” Reeder said Mote said he fears climate change will directly impact capital investments. “I would certainly look at the Port of Seattle, Port of Tacoma and Port of Olympia [as areas of concern],” Mote said, because large amounts of money are invested in those areas.

Reeder emphasized the importance of recognizing that global warming is both natural and aided by humans. “The truth lies in the middle,” he said.