Global Climate Change

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Global Climate Change

• Is it happening? Why? What can we do?

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Can it happen?

• We know, for a fact, that climate has changed
  many times in the past.

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Problems with climate change

• How do we prove that anything is happening to
  the climate at all? The difference between trends
  and events.
• How do we know this is not the normal state of
  affairs? After all we had ice ages and sea-level
  changes in the past.
• How do we prove that what is happeningif
  anything is happening--is caused by human
  activity? Is this an Act of God or the Hand of
  Man?
• What is the nature of the cause and effect
  relationship between human activities and
  climate change phenomena? What is causing what?
• What is the price of doing something about human
  activities accentuating climate change? What is
  the equity position about doing something to
  reduce global atmospheric change? Are the people
  causing most of the problem likely to be the ones
  (a) most affected (b) paying the most for a
  solution?
• What nature of policy is needed? Global,
  national, international? Is the will there to do
  it?

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Potential impact of climate change
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What causes it?

• Well, first of all we dont exactly know
• But, there are two possibilities.

Changes in the Solar Constant
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Cause 2

• The Hand of Man

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What is the scale?

• SO2 is mostly a regional effect because it does
  not do damage until it combines with water and
  comes to earth as acid precipitation.
• CO2, on the other hand affects us directly while
  still in the atmosphere

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The Greenhouse Effect

• You can experience this any time by sitting in
  your car in the sun, and closing all the windows.

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The Physics of it.

• The energy coming into the earth from the sun is
  short wave energy and it passes through air and
  glass with no effect.
• However, and most people never realize this, the
  Earth is heated from BELOW, as the suns energy
  strikes the surface, heats it up, and it, in turn
  puts out long wave radiation that is trapped by
  glass and CARBON DIOXIDE

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More Physics

• CO2 is, remember, only 0.03 of the atmosphere,
  but that maintains our earth at a steady
  temperature.
• Clearly, relatively small changes would have a
  huge effect.
• Including

Rising temperature melts glaciers, ice becomes
sea water, and sea expands as it itself is warmed
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Does everyone suffer?

• Not all the news is bad.

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But climate change comes like this

• Extreme events

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It has even intrigued Hollywood