Global Environmental Change

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Global Environmental Change

• Climate Change, Global Warming
• whats going on?

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What is Climate?

• Climate the average and variations of weather
  over a long period of time (30 years)

Above Global average for atmospheric water vapor.
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What is Weather?

• Weather all natural phenonmena within the
  atmosphere at a given time (hours to days)

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What is Science?

• Science is the search for knowledge

The extent of snowfall as the seasons progress
from Summer into Winter and then back to Summer
again.
The lunar cycle
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How do these combine?

• Used to understand the physics, chemistry and
  biology of the Earth.

Science is the search for knowledge
The Nitrogen Cycle
The Water Cycle
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The Climate System
Oceans
Atmosphere

• The Earth has many different systems that
  interact with each other in different ways.

Ice
Biosphere
Land
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Modern Climate Systems

• Atmospheric circulation

Sunlight
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Modern Climate Systems

• Atmospheric circulation

P.C.
F.C.
H.C.
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Modern Climate Systems

• Ocean circulation

Sinking cool water, rising warm water and wind
help to form global ocean current systems.
The Great Ocean Conveyor
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Modern Climate Systems

• Atmosphere and Greenhouse Effect
• The Earths atmosphere keeps it around 30C
  warmer than it would otherwise be.
• This is the Greenhouse Effect

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What is the Greenhouse Effect?
cc. Robert A. Rohde (Global Warming Art)
The temperature of the Earth depends on the
amount of energy we receive from the sun versus
the amount of energy lost back out to space.
cc. Robert A. Rohde (Global Warming Art)
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Past Climate Systems

• How do we know about climate systems in the past?

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Past Climate Systems

• 1. Early human record

cc. W.V. Bailey
Rock paintings provide evidence of fertile Sahara
region (now desert) 6,000 years ago.
Tourism NT http//www.travelnt.com
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Past Climate Systems

• 2. Geomorphology

River deltas show where rivers entered the ocean
or a lake.
Above A U shaped valley shows that it was
formed by a glacier.
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Past Climate Systems

• 3. Geological record

Drilling into the ground can recover rock layers
that record what conditions were like when the
rock was deposited.
Fossils preserve evidence of past life.
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Past Climate Systems

• 4. Ice cores

Ice cores can preserve seasonal layering.
Studying the chemistry of each layer can give
clues about climate change.
GISP2 ice core at 1837m depth with clearly
visible annual layers.
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Practical Exercise

• Climate Change What can I do?

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Is the Climate Changing?
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What is Climate Change?

• Records change over decades to millions of years

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What are the current climate trends?
Global temperature for the last 150 years
cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/ImageInstrumental_Temperature_Record_png
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What are the current climate trends?
cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/ImageGlobal_Warming_Map_jpg
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Looking further into the past
Global temperature for the last 1000 years
cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/Image1000_Year_Temperature_Comparison_png
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Looking further into the past
Global temperature for the last 450,000 years
cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/ImageIce_Age_Temperature_Rev_png
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Looking further into the past
Global temperature for the last 500 million years
cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/ImagePhanerozoic_Climate_Change_Rev_png
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Anthropogenic Influence

• Fossil fuel
• Aerosols
• Cement manufacture
• Land use
• Livestock

cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/ImageCarbon_Dioxide_400kyr.png
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Future predictions

• Based on no changes in emissions (business as
  usual)
• The UK would be 2-3.5C hotter on average.

cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/ImageGlobal_Warming_Predictions_Map_jpg
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What does it all mean?

• Sea level rise
• More extreme weather
• Changes in precipitation
• Spread of disease

cc. Robert A. Rohde http//www.globalwarmingart.c
om/wiki/ImageRecent_Sea_Level_Rise_png
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Questions to be answered

• How fast will the sea level rise?
• How much warmer will it get?
• When will the Arctic Ocean be ice-free?
• Will the water cycle accelerate?
• Are climate extremes increasing?
• Will there be abrupt changes?

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Science can provide knowledge
We all have to provide the solutions.