The Pacific Northwest Climate CIGnal
The Climate Impacts Group (CIG) issues a quarterly electronic newsletter designed to provide updates on regional climate and climate-related research, meetings, and topics of interest to Pacific Northwest (PNW) decision makers and resource managers. The first newsletter was distributed in January 2005.
To subscribe to the newsletter, please visit the CIG's "climateupdate" list serve home page. You can also subscribe to the newsletter by sending a blank email to the following address: firstname.lastname@example.org.
The Pacific Northwest Climate CIGnal
Issue #26, Summer 2011
In this Issue
- Climate Outlook
- Registration open for the 2nd annual PNW Climate Science Conference
- Tree-Ring Reconstructions of Snowpack Indicate North-South Synchrony in Snowpack Decline Is Rare
- Impacts of Climate Change and Variability on Transportation Systems and Infrastructure in the PNW
- Extreme Precipitation and Temperature over the U.S. Pacific Northwest: A Comparison between Observations
- Tree Ring Study Promisingly Reconstructs Past ENSO Cycles
- Additional Upcoming Climate-Related Conferences
- Recent Noteworthy Climate Change Reports and Tools
- CIG in the News
- CIG publications
What's next for the Pacific Northwest? Despite the cooler than normal conditions that have persisted, the Climate Prediction Center (CPC) seasonal temperature outlook indicates equal chances of below, equal to, or above normal temperatures for most of the region. Read more on the outlook for the Pacific Northwest...
Registration is now open for the 2nd Annual PNW Climate Science Conference, which will take place in Seattle at the University of Washington on September 13 – 14, 2011.
The Climate Science Conference aims to stimulate a place-based (rather than discipline-based) exchange of information about emerging climate, climate impacts, and climate adaptation science in the PNW. The conference will also include time for presentation of emerging policy and management goals, objectives, and information needs related to climate impacts and adaptation. The conference is receiving support from several regional research institutions, federal and state government agencies, and non-profit groups.
Registration closes on September 7th. Please visit the conference website for more information and links to the registration page.
Over the last several years, research on the trends and variability in snowpack in the western U.S. have concluded different things about the degree to which climate change has affected snowpack. For the snow-dependent water supplies that serve tens of millions of people, however, the impacts of current and future climate on snowpack are critical. This years' persistent snowpack in the Northwest and Rocky Mountains served to underscore the variability inherent in snowpack. Unfortunately the observational record of snowpack is not as long in most places as we would like to understand the role of winter and spring climate variability and its effect on snowpack in the West.
To better understand the natural variability in snowpack over a much longer period, and to put recent trends in snowpack in a longer context, Greg Pederson (USGS) and a team of authors from USGS, University of Wyoming, UW College of the Environment, University of Arizona, and University of Western Ontario developed reconstructions of snowpack from tree rings for watersheds in three regions of the Rocky Mountains, including the Southern Region (southern Rockies/ upper Colorado River region), Greater Yellowstone region, and Northern Region (northern U.S. Rockies / southern Canadian Rockies region).
We developed tree-ring records from several different long-lived tree species sensitive to climate and also used publically available chronologies for a total of 66 sites around the western U.S. and Canada. We used the contrast between snowpack limited trees (usually at high elevations) and drought limited trees (usually at low elevations) to develop reconstructions of snowpack by watershed.
We found that the "di-pole", or north-south see-saw pattern of winter precipitation anomalies over the Northern Region and Greater Yellowstone vs. the Southern Region appeared to dominate most of the time over the last 800 years. In fact, except for a period centered on the 1350s and another in the late 1300s / early 1400s, there were no simultaneous multi-decadal declines in snowpack in all three regions (Figure 1). The declines in the latter 20th century across the three regions are thus a rare feature over the last several centuries, and point to the increased role of warmer temperatures reinforced by decadal variability. Furthermore, reductions in snowpack underscore the need to understand the mechanisms of coupled ocean-atmosphere variability and warming trend that have likely resulted in anomalously low snowpacks of the last few decades in many of these watersheds.
Figure 1. Decadal-scale antiphasing of the N-S snowpack dipole and periods of synchronous snowpack decline. The 20-year splines of the regional average snowpack anomalies highlight antiphasing and variability at decadal scales. The shaded bars highlight periods of synchronous snowpack decline. (Source: Science DOI: 10.1126/science.1201570. Reprinted with authors' permission).
Contributions to this article from Jeremy Littell (UW/CIG) and Gregory Pederson (USGS/Northern Rocky Mountain Science Center).
4. Impacts of Climate Change and Variability on Transportation Systems and Infrastructure in the PNW
The consequences of extreme climatic events can be debilitating for transportation systems and road infrastructure in the PNW (see photo). A recent white paper written by the CIG for the Western Federal Lands Highway Division of the Federal Highway Administration examines the impacts of climate variability and change on PNW transportation systems and infrastructure. In particular, the paper reports the following findings:
- Many extreme events in the PNW during the 20th century can be linked to climate variability, including the inter-annual El Niño Southern Oscillation (ENSO) and the inter-decadal Pacific Decadal Oscillation (PDO). However, the majority of regional climate variability in the winter (the season when most extreme events occur in the PNW) cannot be attributed to ENSO and PDO. Despite uncertainties surrounding the causes of climate variability, the upward direction of temperature departures due to projections of climate change are unequivocal.
- Global climate change is projected to bring warmer temperatures and changes in the seasonality of precipitation in the PNW. These changes are projected to lead to increased extreme high temperatures; decreased extreme low temperatures; decrease mountain snowpack; wetter conditions in winter, spring, and fall; drier summers; and changes in hydrologic extremes such as flooding, which may increase or decrease in different ways in different parts of the PNW.
- Loss of snowpack may decrease avalanche risks at moderate elevations (such as mountain passes) while raising the risk of landslides, debris flows, and scour due to an increase in exposed soils.
- Uncertain changes in precipitation extremes may affect the performance of stormwater systems, the frequency of infrastructure damage, and public safety.
- Sea level rise is projected to threaten coastal transportation infrastructure such as roads in low-lying areas, roadways on dikes and levies, or in coastal areas subject to beach erosion. Sea level rise may also create drainage problems in low gradient areas.
- Traditional design processes that assume a stationary climate, or the "replace-in-kind" policies that are currently part of some federal maintenance and funding programs, may become less effective over time given projected changes in 21st century climate. This could lead to increased rates of infrastructure failure if alternative approaches are not developed.
The report concludes with guidance on how design processes and infrastructure maintenance operations may be broadly adapted to incorporate climate change impacts. For example, design standards can be based on modeling projections rather than retrospective data, or may use monitoring to modify current practices as problems become apparent. Flexible designs for structures, such as expandable sea walls and levies, may allow infrastructure to be modified if necessary to withstand more extreme events. The effective integration of science and engineering in the regulatory framework of transportation design and operation will require that the approval processes and updates are likewise flexible enough to respond to changing conditions.
For more details, see: Hamlet, A.F. 2011. Impacts of Climate Variability and Climate Change on Transportation Systems and Infrastructure in the Pacific Northwest. A report prepared for the Federal Highway Administration, Western Federal Lands Highway Division. Climate Impacts Group, Center for Science in the Earth System, Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle.
5. Extreme Precipitation and Temperature over the U.S. Pacific Northwest: A Comparison between Observations
Extreme temperature and precipitation events can have costly consequences for communities, including impacts on human health, strains on energy supplies, and extensive flooding. Climate change is expected to increase the frequency and/or magnitude of extreme temperature and precipitation events.
One way of testing whether regional climate models (RCMs) accurately represent weather and climate patterns in a region (and therefore test the utility of RCMs for projecting changes in climate) is looking at how well regional climate models can replicate observations. In a recent study by CIG researchers, models designed to simulate regional climate were successfully applied to characterize extreme weather events in the Pacific Northwest. The results of this study were published in the April issue of Journal of Climate. Observed indices of extreme events for 72 stations around the PNW archived in the Historical Climatology Network datasets were compared with the climate simulations generated from two different regional models.
The results from the models were similar to the observed datasets, which has promising implications for the ability of forthcoming models to capture extreme events. Boosting the capability of regional climate models to accurately represent extreme weather events will increase our ability to anticipate and withstand the impacts to natural resources.
The El Niño/Southern Oscillation (ENSO) is a major contributor to climate variability in the Pacific Northwest. ENSO is a cyclic phenomenon characterized by two alternating phases: the warm El Niño phase, generally followed by the cool La Niña phase. These phases manifest initially in anomalous sea surface temperatures in the equatorial Pacific Ocean and have impacts on weather and climate patterns worldwide. In the PNW, El Niño is associated with drier, warmer winters and La Niña increases the odds for cooler, wetter winters (like this past one).
Seasonal forecasting of ENSO events has become routine and those forecasts are increasingly being integrated into water resources management, emergency planning, and others areas affected by ENSO. Understanding how ENSO patterns will change in a warmer future climate and incorporating the phenomenon into global climate models is a more challenging endeavor, however.
A recent study published in Nature Climate Change may help address this challenge by providing a continuous, annually resolved record of ENSO variability to help calibrate ENSO's influence in climate models.
A team of researchers led by Jinbao Li of the International Pacific Research Center at the University of Hawai'i at Manoa used tree ring records from the North American Drought Atlas to reconstruct El Niño patterns over the past 1,100 years. The reconstructions show that El Niño has been highly variable, with decades of strong El Niño events (particularly since the 18th century) and decades of little activity (the weakest during the Medieval Climate Anomaly in the 11th century) (Figure 2). When the reconstructions were included in model simulations of past climate, the ENSO pattern that emerged agreed with the known trends of ENSO based on isotopic concentrations of living and fossilized corals in the central Pacific.
The article's citation is as follows:
Li, J. S.-P. Xie, E.R. Cook, G. Huang, R. D'Arrigo, F. Liu, J. Ma, and X.-T. Zheng. 2011. Interdecadal modulation of El Niño amplitude during the past millennium. Nature Climate Change 1: 114–118, DOI: doi:10.1038/nclimate1086
CIG's Climate and Water Forecast Webinar
Each fall, the CIG, in collaboration with various governmental and institutional agencies, hosts a meeting for researchers, stakeholders and water managers to discuss seasonal climate and water forecasts for the PNW. Presentations for the west-side workshop focus on the Columbia River Basin and coastal drainages for Oregon and Washington; the Idaho meeting focuses on the Columbia and Snake River basins.
This year, the CIG is moving the forecast portions of the Washington/Oregon Climate and Water Meeting for the 2012 Water Year to a new format – a webinar. We've decided on a webinar given 1) the tight travel restrictions many participants face, and 2) September's PNW climate science conference, which will provide an opportunity to hear the types of science updates usually provided at the fall forecast meeting. We anticipate hosting the webinar in October.
Stay tuned for more updates about this year's fall forecast webinar.
Third Annual Symposium on Transboundary River Governance in The Face of Uncertainty: The Columbia River Treaty, 2014
Registration is now open for the "Third Annual Symposium on Transboundary River Governance in the Face of Uncertainty: The Columbia River Treaty, 2014", which will take place in Kimberly, BC, from Monday, October 3rd to Wednesday, October 5th. Hosted by the Universities Consortium on Columbia Basin Governance, the objectives of the symposium are to:
- Utilize a unique forum to facilitate cross-border dialogue and communication,
- Explore alternative interests and scenarios regarding the future of governance in the Columbia River on both sides of the border, and
- Raise awareness of the Columbia Basin Trust and of the research done by the Consortium.
The symposium will focus on a transboundary group discussion of alternative scenarios for the Columbia River Treaty and related questions and considerations. The objective of symposium is to produce a set of revised scenarios and related ideas, considerations and commentary that the symposium participants would like the Entities and Sovereigns on both sides of the border take into serious consideration in their deliberations and public processes around decisions about renegotiation of the Columbia River Treaty.
Water in the Columbia Basin: Sharing a Limited Resource
The Columbia River Basin (CRB) is the fourth largest watershed in North America and has been extensively developed for flood control, hydropower generation, irrigation, and navigation. In addition, the river is managed for the protection of salmonid species listed under the Endangered Species Act, municipal supplies, water quality, and recreation, creating a myriad of competing demands.
Complex problems require unique solutions built on the mutual understanding of science, economics, social values, policy, and legal constrains integrated across numerous jurisdictional boundaries. Using presentations, featured speakers, panel discussions, and a poster session, this conference will present the latest regional efforts from a variety of stakeholders aimed at disseminating water resources knowledge throughout the Basin and sharing lessons learned broadly applicable here in the PNW.
The conference will take place on November 2-4 at Skamania Lodge in Stevenson, WA. Vist the conference website for more details.
America's Climate Choices
The National Research Council has released the fifth and final report in the America's Climate Choices series, a suite of studies requested by Congress. This final report, also titled America's Climate Choices, outlines the nation's options for responding to the risks incurred by a changing climate. The report uses the series' four previous reports as a foundation to build a case for why the U.S. needs a plan to manage the risks to society and why the plan needs to be adaptable to future changes. Essential elements of an effective national response identified in the report include the following:
- Enacting policies and programs that reduce risk by limiting the causes of climate change and reducing vulnerability to its impacts;
- Investing in research and development efforts that increase knowledge and improve the number and effectiveness of response options available;
- Developing institutions and processes that ensure pertinent information is collected and that link scientific and technical analysis with public deliberation and decision making; and
- Periodically evaluating how response efforts are progressing and updating response goals and strategies in light of new information and understanding.
Other reports in this series include: Adapting to the Impacts of Climate Change, Advancing the Science of Climate Change, Informing an Effective Response to Climate Change, and Limiting the Magnitude of Future Climate Change.
Guidelines for Coastal Flood Hazards in British Columbia
The British Columbia Ministry of the Environment has released updated guidelines for the management of lands subject to coastal flood hazards associated with climate change-induced sea level rise. Guidelines for Management of Coastal Flood Hazard Land Use is intended for use by local governments, land-use managers and approving officers that develop and implement land-use management plans in coastal areas. The document includes a summary of climate change impacts on coastal land use management and detailed guidance on setbacks, land use planning strategies, and zoning for risk.
Climate research and data for the state of California is being made publicly available through a clearinghouse website, Cal-Adapt.org, sponsored by the California Energy Commission (CEC) and the California Natural Resources Agency. The CEC's Public Interest Energy Research (PIER) program funds and manages the website project. The information is compiled from peer-reviewed climate change research, which is also funded by the PIER program. The website displays local climate information in a variety of formats, from plots to maps; and it provides a wide-range of climate information, from data to publications and resources for climate change in particular communities.
Rolling Easements Primer - The EPA Climate Ready Estuaries (CRE) Program
This primer examines rolling easements as an alternative adaptation measure to sea level rise in areas where traditional protective measures may prove economically or environmentally unviable. The rolling easements are a series of approaches that would allow wetlands and beaches to migrate inland as the sea levels rise in the future. These plans are provide a framework for coastal development by the private sector, state and local governments in anticipation of beach migration inland. The full primer is available at the following website: http://www.epa.gov/CRE/downloads/rollingeasementsprimer.pdf
- Forces of nature combine for cold, wet spring (News Register, May 13, 2011)
- BuRec Report Catalogs 'Possible' Climate Impacts (NW Fishletter May 12, 2011)
- Climate Change Increases Threat of Fire to U.S. West (Scientific American, May 26, 2011)
- Snowpack Science Reveals Changing Climate Pattern in the Northwest (Oregon Public Broadcasting June 9, 2011; Discovery News June 9, 2011)
- Snowpack declines in Northern Rockies, Upper Columbia region 'almost unprecedented' in last 800 years, study says (Oregonian, June 9, 2011)
- Climate change will cost now – or much more later (News Tribune June 12, 2011)
- Signs of global warming found in ancient tree study (Standard-Examiner, June 17, 2011)
- Don't let cool spring fool you, experts say global warming is a fact (Yakima Herald June 26, 2011)
- Climate Change Affects our Shores (Guam Pacific Daily News July 5, 2011)
- Dulière, V., Y. Zhang, E.P. Salathé. 2011. Extreme Precipitation and Temperature over the U.S. Pacific Northwest: A Comparison between Observations, Reanalysis Data, and Regional Models. Journal of Climate. Vol. 24, No. 7: 1950-1964.
- Littell, J.S., D.L. Peterson, C.I. Millar, and K. A. O'Halloran. 2011. U.S. National Forests adapt to climate change through science-management partnerships. Climatic Change. DOI 10.1007/s10584-011-0066-0
- Pederson, G., S.T. Gray, C.A. Woodhouse, J.L. Batencourt, D.B. Fagre, J.S. Littell, E. Watson, B.H. Luckman, L.J. Graumlich. 2011. The Unusual Nature of Recent Snowpack Declines in the North American Cordillera. Science. Vol. 333 no. 6040 pp. 332-335.
Posted August 5, 2011