Minding the Climate
OSU scientists share global warming findings
BY EVA SYLWESTER
Climate change is coming, and learning to adapt to it will be necessary, OSU scientists told Oregon legislators at a meeting put on by the House Interim Committee on Energy and the Environment at OSU’s LaSells Stewart Center in Corvallis April 4.
Jeff Shaman, an assistant professor at OSU’s College of Oceanic and Atmospheric Sciences, summarized the U.N. Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, published in 2007, for the legislators. The report, a large synthesis of climate research, found that most of the observed increase in global average temperature since the mid-20th century has a 90 percent likelihood of having been caused by humans, through energy and agricultural practices that produce greenhouse gases such as carbon dioxide, methane and nitrous oxide.
Arctic temperatures are increasing at almost twice the global average rate, and the melting ice causes sea levels to rise, according to the IPCC report. The report also forecasted more intense and longer droughts and more intensity in the hydrologic cycle, which regulates the circulation of Earth’s water, as effects of climate change.
Rep. Ben Cannon (D-Portland) asked how anomalies such as this winter’s above average snowpack fit into these trends. Shaman clarified that weather and climate are two different things. Climate is the statistics of weather, measured over long periods of time and large geographic areas.
“It’s very difficult for individuals to observe that,” Shaman said, adding that in projections of future climate that have most of the world warming, a few areas may actually cool.
Ron Neilson, a bioclimatologist at the Forest Service’s Pacific Northwest Research Station and a courtesy professor at OSU, discussed climate change’s impacts on vegetation. He presented a number of projections, all of which showed more rain at higher latitudes and drying in subtropical zones; the differences between various projections were the boundaries of the wetter and drier zones.
Neilson said he was concerned more about how drastic the changes between wet and dry conditions would be than about whether rain would increase or decrease in the Pacific Northwest. Before the 1970s, he said, weather fluctuations were relatively benign; today’s wet-dry cycles are intense by comparison. This is a problem because ecosystems naturally operate at drought thresholds, supporting as many plant leaves as they possibly can with the water available. When drought stress occurs, a massive dieback of plant life takes place. Drought stress is more likely when a long period of dryness follows a long period of wetness, as opposed to when wet and dry periods alternate regularly, and Neilson predicted it would happen more often as the climate changes.
“The future will not echo the past,” Neilson said. In dealing with climate change, keeping ecosystems functional in relation to changes may be more important than keeping them preserved in a given condition. While some high value ecosystems could be maintained at high cost, he said, holding back the tide would be hard.
To guard against diebacks from drought stress, Neilson advised managing ecosystems so that they do not reach the drought threshold. To do this, he said, a new workforce and new infrastructure would be needed to thin forests and turn biomass into fuel. He also said the system for dealing with climate change must be interactive and must not rigidly separate intertwined issues such as fire and carbon policies.
Rep. Chuck Burley (R-Bend) said the existing forest products infrastructure could be augmented to meet those needs.
Stella Coakley, associate dean of OSU’s College of Agricultural Sciences, said that while the overall effect of global warming on U.S. agriculture was not projected to be large, different regions would experience it differently. The impact in the South would generally be negative, and the impact in the Midwest would be mixed, but the Pacific Northwest might actually benefit. Climate change tends to produce extreme fluctuations, which are hard on perennial crops such as fruit trees, but a general trend of warming will shift which crops thrive where. For instance, a temperature increase of only 1 °C (1.8 °F) could make some areas in California that currently produce wine unable to do so, but it could also make Oregon able to produce a greater variety of wines.
Mark Abbott, dean of OSU’s College of Oceanic and Atmospheric Sciences and vice-chair of the governor’s Global Warming Commission, said Oregon has the opportunity to lead the country on the climate change issue with new policies and planning. One example is the Oregon Climate Change Research Institute, which is headquartered at OSU and also includes the UO and other Oregon public universities. This institute was founded with the passage of HB 3543 in June 2007 and received $180,000 from the state’s General Fund that July; Abbott said it would receive $360,000 each biennium thereafter.
Corvallis Mayor Charlie Tomlinson urged the legislators to keep local government involved in climate change issues and said there should be an effort to make Oregon’s wastewater treatment plants, which represent 5 percent of the state’s electricity usage, carbon neutral.