California State University Long Beach 

What do we do about global change?

• Need to understand:
• What are the likely environmental changes?
• What are the likely impacts on humans?
• What can we do to mitigate the forecast changes?
• What can we do to adapt to the inevitable changes?

---

What are likely environmental changes?

• United Nations Intergovernmental Panel on Climate Change (IPCC)
• Predictions of regional-scale change are highly uncertain!

 
• Loss of natural habitats and biodiversity
• Occurring at an extremely rapid rate

 
• Weather
• Changes in the distribution and intensity of:
• Rainfall/floods
• Annual U.S. continental rainfall has increased this century
• Predicted to increase 0.5-1% per decade through 2100 A.D.
• Hurricanes/wind storms
• Drought/heat waves
• Shifting of agricultural provinces
• Likely already occurring
• El Niño frequency
• Migrating animals, e.g.:
• Marine life
• Edith’s checkerspot butterflies

• Sea level rise
• Rising this century (10-20 cm), but not yet accelerating
• 9 to 88 cm (best estimate = 48 cm) by 2100 A.D.

 
• Atmospheric pollution
• Global warming
• Rapid increase in greenhouse gases
• Carbon dioxide (CO2) (up 31% since 1750)
• Chlorofluorocarbons (CFC’s) (no natural occurrence)
• Methane (CH4) (up 151% since 1750)
• Nitrous oxide (N2O)
• Partially balanced by cooling, reflective sulfate aerosols
• Detected increase in global temperature (0.6°C in last 100 years)
• Predicted increase of 1.4 to 5.8°C by 2100 A.D.

• Ozone depletion
• Increased CFC’s (Chlorofluorocarbons)
• Refrigerants and inert propellants
• None in preindustrial atmosphere
• Success story -yeah!
• Rowland and Molina (UCI) proposed that CFC’s would act to catalyze ozone breakdown
• Antarctic Ozone Hole recognized
• Vienna Convention (1985) & Montreal Protocol (1990)
• Agreement to phase out CFC production and release
• Just reaching maximum stratospheric CFC concentrations now

Long-lived CFCs will likely persist at elevated level through ~2050 A.D.

Back to the Beach!

Or click  here to return to the Department of Geological Sciences home page