The Challenge of Global Climate Change

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The Challenge of Global Climate Change
Prof. Dr. Mojib Latif Leibniz Institute of Marine
Sciences, Kiel University
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Outline

• Causes of climate change
• What can we observe today?
• Projections for the 21st century

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1. Causes of climate change
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The earth at night
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The composition of the earths atmosphere
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We produce trace gases
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Increase of carbon dioxide
today 380 ppm
x
1800 280 ppm
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The greenhouse effect
temperature without -18C with 15C
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2. What can we observe today?
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Global temperature since 1880
0.8C
NASA
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The last millenium1000-2000
today
x
Northern Hemipshere temperature
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Temperature anomaly 2006
NASA
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Who is responsible? Natural forcing cant explain
the warming
IPCC 2007
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Arktic sea ice retreats
March values (Mio km2) 1978-2006
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Retreat of sea ice Opening of the North East
Passage
1979
2005
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Greenland melts
sea level rises by 7m if Greenland melts
completely
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The mountain glaciers meltPasterze, 100 years
ago
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The mountain glaciers meltPasterze, today
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Sea level rise during the last 125 years
present rate 3 mm/year
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Heavy precipitation events 1879-2000
Hohenpeissenberg, Bavarian Alpes
heavy precipitation events per year
year
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Katrina
Are Hurricanes changing?
28 tropical storms in 2005 9 tropical storms in
2006
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3. Projections for the 21st century
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The inertia of the climate system
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CO2-scenarios until 2100
Emissions and concentrations of CO2 1990-2100
(IPCC)
year
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Temperature change 1990-2100
global mean surface air temperature
IPCC 2007
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Maximum global warming until 2100
max. Global warming
Eemian warm period
last ice age
today
thousands of years bp
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Response to CO2 doubling
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Sea level change 1990-2100
Global mean (without ice melt)
Only thermal expansion
sea level increase (cm)
year
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Sea level rise in the past and in the future?
Sea level increase of 80 m
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The next millennium
CO2-emission
CO2-concentration
temperature
sea level
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Summary

• Global climate change is real.
• If we do not act, we shall experience an
  unprecedented global warming until 2100, with
  significantly more extreme weather events and a
  sea level rise of about 1m.
• To avoid this the emissions of greenhouse gases
  into the atmosphere have to be reduced to a small
  fraction. This can be achieved only by the
  introduction of renewable energies in the
  long-term.
• The transition from a carbon-based to a
  carbon-free economy can evolve slowly over the
  next 50 to 100 years.

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Changes in the past