Download Global Climate Change

Global Climate
Change
Is it happening? Why? What can we do?
Can it happen?
• We know, for a fact, that climate has
changed many times in the past.
Problems with climate change
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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 happening—if 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?
Potential impact of climate change
What causes it?
• Well, first of all we don’t exactly
know and we certainly cannot prove
any of the possibilities in the strict
scientific sense.
• But, there are two possibilities.
Cause 2
• The Hand of Man
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
The “Greenhouse Effect”
• You can experience this any time by
sitting in your car in the sun, and
closing all the windows.
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 sun’s energy strikes
the surface, heats it up, and it, in
turn puts out long wave radiation
that is trapped by glass and CARBON
DIOXIDE
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
Does everyone suffer?
• Not all the news is bad.
But climate change comes like this
• Extreme events
It has even intrigued Hollywood