Climate Change Forum,
Dr. Nancy Wilgenbusch, President,
personal, overlapping, permeable, and intertwined with economics. The Personal—world boundaries firmed up as a
child, dinner table conversation about environmental issues. The Chinese use one barrel of oil per person
(vs. 30 barrels for a
Making Sense of What
Scientists are saying about Climate Change, Prof. Ron Mitchell,
Scientists say that global warming is unequivocal. Although natural variability exists, the human cause is “very likely.” The response- acceptance, adaptation, and mitigation. More climate change expected in the future. The Intergovernmental Panel on Climate Change (IPCC) has Science, Impacts, and Response working groups. IPCC consolidates, not produces, existing knowledge on climate change science. Why should we believe the IPCC? Many studies, all peer-reviewed, offer environmental signs that point in the same direction, align with theoretical predictions, even with differing perspectives.
Basic science facts:
increased temperatures, increase in unusual weather, and carbon dioxide gas
increase (www.vitalgraphics.net/climate2.cfm). Do other impacts line up? Natural plus human cause, combined, gives the
best fit of the observed data. Global
warming is part of climate change and associated other impacts (e.g., change in
precipitation/snow distribution, frequency, and intensity, extreme events,
sea-level rise). Observed global
warming: +1 to +2 degF, since 1900.
Future warming: +2 to +11 degF by 2100.
Action- cut emissions by 60% from 1990 levels. American society is a major problem, with its wasteful consumer ethic. Many of the climate change impacts will be permanent- species loss and snow loss. Adaptations: dams, seawalls, and power-plants. Mitigation costs: 1-4% global GDP or 5% without a plan of action.
and Why, Prof. Christina Hulbe,
Climate is a
statistical composite. Earth’s orbit,
ocean circulation, and continental location determine the Earth’s climate
patterns, as the physics of fluids in motion.
Major climate modes- northern (Arctic Oscillation, North Atlantic
Oscillation), tropical (ENSO, Pacific-North America pattern, southern annular
mode, mean monthly Sea-Level Pressure).
IPCC 3rd Assessment graph shows natural, human, and combined
temperature anomalies. The Southern
Polar Vortex shows increased circulation so the ice break-up around
Lessons from Past
Climate Change, Prof. Alan Mix,
system is sensitive to change due to small forcings. How sensitive were past climates? Paleoclimatology looks at proxy data (i.e.,
representative signals that indicate past climate conditions) from sediments,
fossil plankton, isotope geochemistry, etc.
However, is proxy data truly representative of what you seek? One example is counting foraminifera
(temperature sensitive) in ocean sediment cores. About 21,000 years ago, the ocean surface
changed by 2-3 degC, cooling at high latitudes, with a ~5 degC global change
2001). Observations are in good
agreement with model output (Hewitt et.al, 2003) but
disagree on stability of sub-tropics and cooling ocean boundaries. Ice Age forcing factors: ice-sheet,
vegetation, -3.5 W/m2,
greenhouse gases, -2.6 W/m2,
and aerosols, -0.5 W/m2. Ice cores are good paleo-CO2 proxies.
Antarctic ice CO2 was 200-300 ppm
(“normal”) during 0-400,000 years ago (Alley, 2004). Now, the CO2
level is 380 ppm. Thermal inertia is the
slow lag time of a response in the atmosphere.
So, the CO2 emissions will continue
the atmospheric warming for decades to come.
North America and
Climate Models and
Predicting the Future, Prof. Karen Shell,
Climate is a dynamic energy budget of the Earth. Stable climate means that absorbed sunlight is balanced by outgoing infrared radiation (Kiehl and Trenberth, 1997). CO2 doubling gives +1.2 degC (2 degF) increase in global average temperature, assuming other state variables (e.g., water vapor, clouds, snow) doesn’t change, or +2 to 4.5 degC with feedback loops included. Climate models simulate land surface (e.g., albedo), ocean (e.g., currents, temperature, salinity), and atmosphere processes—all dynamically linked. Current model resolution is “T85” (100x150 km grids or 60x90 mi). In the Future, expect +0.2 degC per decade, on average. Bookend scenarios include B1 +1.8 degC and A1F1 +4 degC. Other impacts include increase in heat waves, precipitation, and extreme weather. High latitudes and continents will warm faster than the tropics and oceans. More certain: increasing temperatures and sea-level rise. Less certain: hurricane frequency and intensity.
Glaciers, Prof. Andrew Fountain,
expanding due to warming temperatures.
Climate Change in the
Pacific Northwest, Prof. William Calvin,
The climate change
problem is underestimated, especially on the time scale. The belief that CO2 can be all absorbed by the ocean changed by the 1950s, as
science greatly underestimated the impact of fossil fuel consumption. During 1950-1973, “global dimming” occurred
due to industrial emissions. The Arctic
sea-ice minimum is measured annually during September. The 2007 minimum has accelerated even since
2005. Other evidence: more extreme
weather events, drought, wild fires, ocean acidification, floods and landslides
(especially in the last 20 years), high wind events, heat waves, and the first
hurricane ever recorded in the
Sustainability in the Face of Climate Change, Jill Sughrue, Sustain NW (www.sustain-nw.com):
Will business as
usual bring litigation tomorrow? There
is more shareholder initiative to alter corporate practices. The Carbon Disclosure Project (www.cdproject.net) asks 2400 companies in
2007 to disclose their “carbon-footprint.”
Common risks – physical, competitive, regulatory, reputational, and
liability. Potential liability claims –
general, product, environmental, professional (officers and board of
directors), political, and vehicle. In
April 2007, the
Note-taker: Kyle Dittmer, President (2005-2008), Oregon AMS