Transcript Lucas_CVAQ_20100130

Climate Change: A Global
Phenomenon with Local
Implications
Ryan Lucas
Sierra Nevada Research Institute
UC Merced
[email protected]
Outline
• Greenhouse Effect
• Global and Regional Temperature Trends
and Forecasts
• Impacts to the Sierra Nevada and Central
Valley
• Summary
Greenhouse Effect
• Increased concentration of greenhouse
gasses in the earth’s atmosphere
• CO2 – burning of fossil fuels
• N2O – manure breakdown, burning of fossil fuels,
industrial processes, fertilizer breakdown
• CH4 – landfills, manure breakdown, permafrost
melt
• H2O – “natural”, increase from melting of ice,
glaciers, and permafrost
Global Anthropogenic
Greenhouse Gas Emissions –
2004
Source: IPCC 4th Assessment Report:Climate
Change 2007: Synthesis Report
Greenhouse Effect
A fraction of the long wave radiation
escapes from the atmosphere;
greenhouse gases absorb the
remaining long wave radiation and
emit long wave radiation in all
directions.
Incoming Solar Radiation
Increase of greenhouse gases results in
more long wave radiation absorbed and
re-emitted and warmer global surface
temperatures.
Incoming Solar Radiation
is absorbed by Earth’s
surface. Surface emits
long wave radiation to
atmosphere
Source: Cayan et
al 2006
Source:
http://globalchange.gov/public
ations/reports/scientificassessments/us-impacts/fullreport/national-climate-change
Source: Cayan et al
2006
Source: Bales et al 2006
Source: Knowles and Cayan 2001
Water Impacts
• Early onset of spring
– Early stream flow
– Loss of reservoir and groundwater storage
– Loss of hydroelectric generated power
• Large winter storms produce rain
– Loss of storage in snow pack
– Induction of floods, rain on snow events
• Longer, drier summers
– Crop and stock stresses
Wildfires
Source: Westerling 2006
Source: Westerling et al 2006
Fire Impacts
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More frequent wildfires
More intense/larger wildfires
Decrease in Central Valley air quality
Loss of vegetation
Loss of wildlife habitat
Release of CO2 to atmosphere
Vegetation
Source: Linehan et al 2006
Vegetation
Source: Linehan et al 2006
Vegetation Impacts
• Potential migration of plant species
• Potential loss of plant species.
• Migration and/or loss of plant species may
lead to migration and/or loss of animal
species.
Sea Level
• Potential for 1-3 feet sea level rise by the
end of the century (Hanak and Lund 2008)
• Alter salinity, depth, and flood potential in
the Sacramento-San Joaquin Delta
Summary
• Mean global surface temperatures have been and will continue to be
on the rise
• Warming of global surface temperatures is a result of increases in
atmospheric greenhouse gas concentrations
• Anthropogenic activities are the major source for increases in
atmospheric greenhouse gas concentration
• Although a global phenomenon, we will experience local impacts
• The western US has seen increased temperatures over the last
century and will see continued temperature increases for the
foreseeable future
• Impacts expected in the Sierra Nevada and Central Valley include:
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Loss in snow pack
Early onset of spring runoff
Longer, drier summers
Increased frequency and severity of wildfires
Decrease in air quality
• The climate will change; how much and how quickly depends on
mitigation and adaptation strategies developed and implicated now
and in the near future
Thank You!