3. The Globe is Becoming Warmer
The head of the state weather service, Alexander Frolov, said that
the heat wave of 2010 was the worst in 1,000 years of recorded
Russian history.
Since the 1970s, each subsequent decade has gotten hotter – and 9
of the 10 hottest years on record occurred since 2000.
1880
1880 2020
3
5. Outline of My Remarks
• Facts about climate change.
• Simple thought exercise on dynamics of flows and
stocks.
• My theory of connection between CO2 emissions
and damage from climate change.
• Summary of the evolution of climate critics.
• Somepositive feedback loops that may counteract
our efforts to control greenhouse gas emissions.
• Some changes required in policy if we wish to slow
down the rise in CO2.
5
6. Some Influences on Heat Balance
• Changes in the intensity of the sun
• Changes in natural absorption and
reflectivity (volcanic aerosols, cloud cover)
• Changes in reflection (ice cover, tree cover)
• Changes in composition of the atmosphere
6
8. Facts about Atmospheric CO2
• Two sources of data:
– Mauna Loa, HI observatory (50 years)
– Ice core data (several thousand years)
• CO2 from fossil fuels is unique, so it is clear
the increase comes from combustion.
• 40% remains in the atmosphere; the rest goes
equally into plants and the sea.
• CO2 concentration is now 30% – 40% greater
than preindustrial levels and it is expected to
double or triple by 2100.
8
10. Climate Change is More Than
Global Warming:
• Changes in precipitation area and intensity of fluctua-
tions (more floods, more droughts, bigger deserts)
• Shifting ecological and cultivation zones
• Growing acidity in the ocean
• Greater instability in winds
• Migration of pests, diseases, pollinators
• Rising sea level
• Melting of permafrost
• Migration of people and industry
10
11. Precipitation is Becoming More Extreme
• Worldwide, 2010 and 2011 were the wettest years
over land in recorded history.
• In the United States 7 states had their wettest year
in history in 2011; several others had their driest
year in recorded history.
• Artic ice fell to its lowest volume in history in
2011.
• Western El Salvador, received nearly 1.5 meters
of rain in 10 days.
11
24. Behavior of the Water
Outt = Levelt / 10
4
Level
In
Out
0
24
25. Main Lessons From Bathtub Dynamics
• The level will continue to increase for an extended
period even after the input starts to decline.
• Even after you take the input to zero, the level
takes a very long time to disappear
25
26. Computer Model of Three Bathtubs in
Series
Acceptable L3 = 5
Normal
ALT1 = 10 ALT2 = 10
In = 0.2
26
30. The Evolution of Climate
Criticisms
• Climate is not changing.
• Climate is changing, but we are not the cause.
• We are causing climate change, but it is late to
stop it.
30
34. The Stern Review recommended urgent,
immediate, and sharp reductions in
greenhouse-gas emissions. These findings
differ markedly from economic models that
calculate least-cost emissions paths to
stabilize concentrations or paths that
balance the costs and benefits of emissions
reductions.
I find that the difference stems almost entirely
from its technique for calculating discounts.
- William Nordhaus in Science July 25, 2007 34
35. Relying on Present
Net Value to Choose Assumes:
• All consequences of an action are known
• All consequences can be expressed in monetary units;
they are commensurate
• We are the ones entitled to pick the interest rate
• Maximizing financial benefits is the goal of society
• Current mistakes can be corrected by paying some cost
in the future
Every single one of these assumptions is false for the
issue of climate change!!
35
41. Potential Sources of Non-Linearity
Positive Feedback Loops
• Ice cover -> heat reflection
• Tundra melt -> methane release
• Water vapour -> heat capture
• Temperature -> forest growth -> CO2 capture
• Sea temperature -> methane hydrate melt
Saturation
• Loss of ocean capacity to buffer CO2 in air
Cataclysm
• Massive fresh water release into the gulf stream
41
