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Devastation in the Legislature
CLIMATE CHANGE IN OUR RIVERS AND OCEANS
By Eva Sylwester
Water prospects in the Midwest, South and Southeast aren’t looking too great. What about Oregon’s water? The Oregon Legislature heard an earful recently — none of it optimistic.
OSU scientists discussed the effects of climate change on the water supply and oceans with Oregon legislators at a meeting of the House Interim Committee on Energy and the Environment in Corvallis on April 4.
Anne Nolin, an associate professor of geosciences at OSU, said snowmelts and springtime stream flows are occurring earlier than they used to in the Western U.S. The low flows of rivers are also lower. As described in a paper she currently has in press about the McKenzie River, this is going on now, not a projection for the future; the McKenzie’s peak flows are now 15 to 17 days earlier than the reference values, she said.
Projections for the future include early peak flows of rivers, which could cause flooding, and snow turning to rain at lower elevations. The frequency of warm winters is expected to increase in general, though there may still be cold winters occasionally, Nolin said.
One difficulty in studying stream flows is that gauges monitoring stream flows are often not maintained or are placed in front of dams or other diversions, thus giving inaccurate readings. Also, snowpack measurements are not taken at sites that are at risk for having rain rather than snow in the future. Nolin said she was working on a schema for representative placement of gauges. She expressed interest in California’s hydrologic observatories, which gather data on the motion of water, as something Oregon could emulate.
Rep. Jackie Dingfelder (D-Portland), who chairs the House committee, noted that the House had authorized more state funding for stream gauges during its last session. She said U.S. Geological Survey funding had been cut and that less federal money was coming in for stream gauges.
Jack Barth, a professor of physical oceanography in OSU’s College of Oceanic and Atmospheric Sciences, said the heat content of oceans has increased during the second half of the 20th century as a result of climate change. The sea level is increasing two millimeters per year, or 0.8 inches per decade, due to thermal expansion and the melting of ice.
Furthermore, Barth said, the increase in carbon dioxide in the atmosphere that is widely believed to be responsible for climate change also directly affects oceans, because atmospheric carbon dioxide penetrates the ocean and makes the water more acidic. The more acidic water makes small organisms such as pteropods, which a scientist of Barth’s acquaintance refers to as “potato chips of the sea” because of their role as food for larger creatures, unable to efficiently form shells. The difficulties of the pteropods then compromise the whole food web.
With higher temperatures on the land from climate change, the land-sea temperature difference leads to changes in wind patterns. The changing winds cause extreme variation in plankton blooms so that there is either not enough plankton to feed everything that needs to eat plankton or too many plankton consuming oxygen to leave enough oxygen for other ocean life, Barth said.