1 / 30

Global Warming and Its impacts on the Pacific Northwest

Global Warming and Its impacts on the Pacific Northwest. Dr. Nathan Mantua University of Washington Climate Impacts Group. For the SWS/SER Annual Chapter Meeting 2006 Vancouver, WA May 2, 2006. Columbia River Basin. The Climate Impacts Group.

chynna
Download Presentation

Global Warming and Its impacts on the Pacific Northwest

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Global Warming and Its impacts on the Pacific Northwest • Dr. Nathan Mantua • University of Washington • Climate Impacts Group For the SWS/SER Annual Chapter Meeting 2006 Vancouver, WA May 2, 2006

  2. Columbia River Basin The Climate Impacts Group A NOAA-funded research and education team at the University of Washington cses.washington.edu/cig

  3. The Greenhouse Effect • There is a natural greenhouse effect that warms the earth’s average surface temperature by ~33 C Pierce

  4. Humans are increasing the greenhouse effect by adding greenhouse gases to the atmosphere • CO2:  by 32% • Methane:  by 150% • Nitrous oxide:  by 17% IPCC 2001

  5. Global Average Surface Temperatures are Rising • From Jones and Palutikof • http://www.cru.uea.ac.uk/cru/info/warming/ ~0.8 C rise in global average temperatures since 1860s

  6. From Hegerl et al. (2006) Nature

  7. Temperature trends (°F per century) since 1920 coolerwarmer 3.6°F 2.7°F 1.8°F 0.9°F

  8. The South Cascade glacier retreated dramatically in the 20th century 1928 Courtesy of the USGS glacier group 2000

  9. Declining April 1 snowpack, 1950-1997

  10. Western snowfed streamflow has been arriving earlier in the year in recent decades Spring-pulse dates Figure by Iris Stewart, Scripps Inst. of Oceanog. (UC San Diego) Center time Spring pulse Centers of Mass Stewart et al., 2005

  11. What about the future?

  12. Pop-culture perspectives Perhaps this is good fiction, but it is not good science Likewise, the Day After Tomorrow scenario might make for a fun movie, but it presents physically impossible impacts of global warming at ridiculous rates of change

  13. 21st century Global Average temperature change Scenarios social unknowns and emissions geophysics uncertainty IPCC (www.ipcc.ch)

  14. Temperature change, 2071-2100 minus 1961-1990

  15. 21st Century PNW Temperature Change Scenarios

  16. Springtime snowpack will decline, especially at the warmest locations + 4.1 ºF (2.3 ºC) & + 4.5% winter precipitation +2.3C, +4.5% winter precip

  17. The coldest locations are less sensitive to warming + 4.1°F + 4.5% winter precip

  18. Sea Level Rise scenarios depend on regional tectonics • tectonic processes and glacial rebound are causing South Puget Sound to subside and the Olympic Peninsula to uplift • this means that relative sea level rise will be greatest in South Puget Sound (~3.3ft by 2100), and least near Neah Bay (~1.3ft by 2100)

  19. With a 2 m sea level rise With a 1 m sea level rise Sea Level Rise and the Lower Columbia River(using Flood Maps: http://flood.firetree.net/)

  20. Climate impacts on salmon must be added to existing stresses across their full life-cycle

  21. Impacts are cumulative … HABITAT CHANGE and DEGRADATION INCLUDING GLOBAL WARMING HARVEST PRACTICES HATCHERY PRACTICES

  22. Temperature thresholds for coldwater fish in freshwater • Warming temperatures will increasingly stress coldwater fish in the warmest parts of our region A monthly average temperature of 68ºF (20ºC) has been used as an upper limit for resident cold water fish habitat, and is known to stress Pacific salmon during periods of freshwater migration, spawning, and rearing. +4.1 °F +3.4 °F

  23. Climate change impacts on Washington’s forests • CO2 fertilization • A transient impact • a longer dry season • reduced regeneration, increased vulnerability to fires and pests (except in especially cool-wet locations) • shifts in species ranges • subalpine forests “invading” alpine meadows; a northward march--or a loss--of species?

  24. Ecosystem thresholds: the case of the Mountain Pine Beetle • a massive outbreak of the mountain pine beetle in BC has killed 100 billion board feet (approx. 9 years of harvest) • low temperatures (< -10°F) limit beetle activity • a recent lack of extreme cold, killing temperatures has allowed the beetle to thrive in epidemic numbers beetle killed pines in BC Photos from http://www.for.gov.bc.cal

  25. Main points • Global climate is changing under human influence • Some effects are already being observed • Future effects a mix of bad and good, and will in part depend on policy decisions now

  26. Climate change sharpens the tradeoffs in a world of multiple stresses • climate change will likely intensify existing conflicts over scarce natural resources • most of our natural resources are now fully allocated and managers already grapple with difficult tradeoffs • summer water supplies for in and out of stream uses are especially vulnerable to climate warming • global warming impacts on the PNW depend on both the climate change and on how we prepare

  27. Choices now • Reduce emissions - makes a big difference beyond 2050 • Prepare for impacts - anticipating change may enhance benefits, minimize risks, and make it more likely to reach planning goals • Examples: city water supplies, salmon recovery plans, habitat conservation and restoration plans, coastal development …

  28. 1950-1997 relative trends in April 1 SWE vs DJF temperature Obs VIC

  29. The natural Greenhouse Effect

More Related