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Is the earth warming?
• Yes, it has been gradually warming for the last 400 years as we exit the Little Ice Age.
• So the real question is:
Has there been significant or unnatural warming in the last few decades?
A Critical Question
• Did the recent warming result from an increase in atmospheric greenhouse gases, primarily carbon dioxide (CO2)?
–OR
• From natural cycles controlled by the
Sun • Let’s look at these 2 competing
hypotheses
The Greenhouse Gases• Make life possible on earth
– Without them earth would be too cold– Not a new phenomenon
• Minor components of the atmosphere – Water vapor is the most important by far– Others include: Carbon dioxide, methane,
and a few others
• Further increases in carbon dioxide will have little effect
Implications
• Lack of correlation between rising CO2 and temperature indicates that other factors are controlling climate change
• This lack of correlation agrees with the record in ice cores and geologic history
What about the solar hypothesis?
• Solar activity is cyclical and drives earth’s climate– Total irradiance – about 20% of the effect
• Only part considered by the UN
– Solar wind & Solar magnetic field• These account for 80% of the effect
• Length of the Sunspot cycle is a good indicator of solar activity– Short cycles are more active & warm earth
Variable solar activity
• Length of the Sunspot cycle is a good indicator of solar activity– Short cycles are more active & warm earth
• What is happening with solar activity?
Sunspot contrast is decreasing.If this trend continues, they will disappear completely in 6 years.
Data from Jan. ’09 show this trend is continuing.
X
The magnetic field of sunspots is losing strength.If this trend continues, sunspots will disappear in 6 years.
Data from Jan. ’09 show this trend is also continuing.
X
So Where Are We At?
• Anthropogenic global warming is not proven– CO2 does not appear to be the main climate driver
– Rather CO2 changes appear to follow temperature changes
• If the solar model is correct we are entering a major cooling phase – that scares me!
• Which will prove correct?• Which will benefit humanity?
What does history tell us?
• Civilization has flourished during warm times– Medieval castles, cathedrals, developing
science• Civilization has suffered during cold times
– Crop failures, starvation, plague
• Which do you prefer?
• Are we going down the wrong road?
Carbon Dioxide – CO2
• Should we try to control CO2 in the atmosphere?– When we are not sure it is a problem.
• CAN we control the CO2 content of the atmosphere?– What are the economic consequences of
spending large amounts to “cure” a problem that may not exist?
CO2 – a Greenhouse Gas
• One source of CO2 is burning of fossil fuels
• Are there alternatives to fossil fuels ?????
Alternative energy Sources
• Solar, Wind, Geothermal, Biofuels, & Nuclear
• Some pertinent questions– Which sources are economically
competitive?– Which sources are environmentally
friendly?– Which sources can meet our needs?
Some Answers
• Of the alternate energy sources –
• Only geothermal and nuclear are currently economically competitive with fossil fuels
• Wind & solar may never be competitive
• Fossil fuels are still abundant– Much of the resource base is off limits
Environmental Problems
• Geothermal and nuclear are the most environmentally friendly
• Wind, solar, and biofuels require huge areas to collect diffuse energy
• Results in a large environmental footprint
• Realistically wind, solar, and biofuels will never provide much of our energy needs
Technical Problems
• Wind and solar are intermittent
• Requires spinning backup to prevent blackouts– Denmark – grid unstable after about 15%– Texas blackout
• Substantial increase in the cost of electricity
The Denmark Experience
• In 2005, it was calculated that wind energy saved Danish consumers $200,000,000
• However, the Danish paid $280,000,000 in subsidies for a loss of $80,000,000
• Since then, Denmark stopped subsidizing wind power and construction of new wind turbines has stopped
• Why is that?
Importance of energy
• Modern civilization requires vast amounts of energy
• The cost of energy affects nearly every aspect of our lives
• Our supply of abundant & inexpensive energy depends on decisions we make– The fossil fuel resource base is available– What will we choose?????????