Transcript Greenhouse effect

What is the
Greenhouse Effect?
How is the
temperature of the
Earth maintained?
What is the Carbon
Cycle?
The Earth’s Energy Balance
Greenhouse
effect
Our atmospheric
gases trap and
return a major
portion of the
heat radiating
from the Earth.
It is a natural,
necessary
process.
3.1
Data in watts
The infrared spectrum for CO2
Wavenumber (mm–1) =
1______
wavelength (mm)
3.4
Climate Forcing/Feedback
How does Earth stay
Comfortable for Us?
• Gaia Hypothesis
– Biological and Physical Processes Produce
Homeostasis
• Negative is Good – Feedback control
• Positive is Bad – Oscillate out of control
http://www.southtexascollege.edu/nilsson/4_GB_Lecture_figs_f/4_GB_16_Homeostasis_Fig_f/Homeostasis_TempControl.GIF
http://apollo.lsc.vsc.edu/classes/met130/notes/chapter16/graphics/neg_feed.free.gif
Edited DEH
http://apollo.lsc.vsc.edu/classes/met130/notes/chapter16/graphics/pos_feed.free.gif
Ice-Albedo Positive Feedback
Temperature
increases
Less Ice on Surface
More Solar Energy
Absorbed and less
Reflected – Albedo
lower
The carbon cycle
3.5
CO2 emission sources by end use:
3.5
Ways to reduce CO2 Emissions
• Where is the Biggest Target?
• Where are the Easy Targets?
Ways to reduce CO2 Emissions
Power Sector
• Energy Efficiency – use less
• Switch from Coal to Natural Gas -50% red.
• Renewable Energy
– Solar electric
– Solar Thermal
– Wind – driven by solar heating of earth
– Hydropower – related to solar
– BioFuels – solar energy capture
• Plant based
• Algae based
Combined Heat and Power
• Use “waste heat”
• 90-95% total efficiency 1/3 the CO2
• Over 200 College and University systems
– Yale 60 Megawatt
– Electricity
– Steam and hot water
How do scientists study climate?
•
•
•
•
Collect data, historical and paleoConsider physical mechanisms at work
Develop models and test them
Limitations of science
– Can’t prove a positive
– Eliminate possibilities
– What remains is accepted
Why is there still a ?
• Correlation does not PROVE Causation
• Climate Models (GCM’s) Still Imperfect
– Cloud Impacts Undertain
• Wishful Thinking
Climate Models are used to predict annual global
mean surface temperatures.
Test Models with Historical Data
Blue bands = predicted temperature range using natural processes
Pink bands = temperature range including human influence
Black line= observed temperature
3.9
Models can also be used to predict future global
temperatures.
Black line = data for the 20th century
Other lines = projected 21st century temperatures based on different socioeconomic
assumptions
3.9
Limitations of Models
• Assume linear change
• Assume same mechanisms of climate
continue to function
• Role of clouds not known with certainty
• Polar Vortex Collapse
• Gulf Stream (Thermo-haline circulation)
• Air Transport in Troposphere
– Convection cell position
Kyoto Protocol – 1997 Conference
• Intergovernmental Panel on Climate Change
(IPCC) certified the scientific basis of the
greenhouse effect.
• Kyoto Protocol established goals to stabilize and
reduce atmospheric greenhouse gases.
• Emission targets set to reduce emissions of six
greenhouse gases from 1990 levels.
(CO2, CH4, NO, HFCs, PFCs, and SF6)
• Trading of emission credits allowed.
3.11
The Kyoto mechanisms
• Emissions trading – known as “the carbon
market"
• Clean development mechanism (CDM)
– Polluters can reduce emissions in developing
countries and get credit.
• Joint implementation (JI).
– Eg. USA could buy forests in Brazil and get
credit for carbon sinks
The Kyoto mechanisms
•
•
•
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Registry System – Record transactions
Annual Reports
Compliance System
Adaptation Fund
– Money to help poor countries adapt to Climate
Change
Where are we today? (2009)
• Copenhagen Meeting
– Kyoto expires in 2012
– Kyoto goals not met
– US, China, India, and Australia never signed
– Need to move forward with new agreement
– Can the US-China-India- and Australia join?
• Meeting begins with real optimism!
Fairness?
4/12/2017
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