Climate Change: The Headline News

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Climate Change The Headline News

• Frances Drake
• School of Geography
• University of Leeds

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Overview of Talk

• Introducing the global climate system
• Predicted changes
• Global
• Regional
• Surprises in the greenhouse

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Why is the Climate Changing?
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Climate System
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Feedback in Climate Changehttp//www.globalchange
.umich.edu/globalchange1/current/lectures/samson/f
eedback_mechanisms/
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Climate Sensitivity

• The ratio of the global mean surface air
  temperature response to the global mean radiative
  forcing (Harvey, 2000).
•  ?T?RF
•  T annual mean surface air temperature
• RF radiative forcing
• ? climate sensitivity parameter

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Surface Observations
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Climate Models
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Yorkshire and Humberside
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Predicted Temperature Changes
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Predicted Winter Precipitation Changes
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Predicted Summer Precipitation Changes
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Model Experiments
Patterns of change in summer-average
precipitation as simulated by nine global climate
models for the 2080s (2071-2100) for the same
(A2) emissions scenario
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Ensemble Forecasting Countering the
Uncertainties

• Natural Variability
• Initial conditions
• Changes in Boundary Conditions (changes in energy
  balance)
• Emission scenarios
• Scientific Understanding (Modelling Uncertainty)
• Perturbed-physics

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Climate Surprises
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Global Dimming
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Summary

• Climate predictions rely on a knowledge of the
  climate sensitivity
• This results in some uncertainty associated with
  the predictions
• Whilst planning for the predicted we cannot rule
  out surprises in the greenhouse