Post on 15-Jun-2015
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The Dynamics of Climate Change
Dennis Meadows Presentation to Mendeleev University
Moscow, Russia 16 April, 2012
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Land Temperatures in Russia – August 2010
Moscow
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The Globe is Becoming WarmerThe 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.
18801880 2020
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Exercise on Dynamics
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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.
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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
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CO2 Concentration
1972
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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.
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400,000 0
Years before today (0 = 1950)
200,000
Current level
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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
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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.
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Simple Thought Exercise
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Bath Tub Dynamics
In
Out
Level
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Bath Tub Dynamics
In
Out
Leve
l
0
10
Levelt=o
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Behavior of the Water
Levelt=0 = 8, In = 0, Out = 0
Time
0
10
0 50
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Behavior of the Water
Levelt=0 = 8, In = 0, Out = 0
Time
0
10
0 50
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Bath Tub Dynamics
In
Out
Leve
l
0
10
Levelt=0
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Behavior of the Water
Levelt=o = 8, In = 0, Outt = Levelt /10
Time
0
10
0 50
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Behavior of the Water
Time
0
10
0 5030
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Bath Tub Dynamics
In
Out
Leve
l
0
10
Levelt=0
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Behavior of the Water
• Levelt=0 = 0, Outt = Level / 10, Int = (graph)
Time
0
4
0 5010
In1
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Computer Model of the Bath Tub
=10
Outt = Levelt /10In
Level
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Behavior of the Water
0
Outt = Levelt / 10
In
Out
Level
4
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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
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Computer Model of Three Bathtubs in Series
Acceptable L3 = 5
Normal In = 0.2 ALT1 = 10 ALT2 = 10
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Dynamics of the Three-Tub System
In
Acceptable L3 = 5
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Dynamics of the Three-Tub System
Maximum L3 = 35
In
Acceptable L3 = 5
Delay = 50
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My Model of the Climate System
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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.
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Use all possible policies
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Four Factors Determine the Amount of CO2 Emissions
© Dennis Meadows; 2007
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Stop using discounted cash flows to make decisions
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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
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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!!
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Increase the planning time horizon of the government
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Easy Problems
Now Future
Bet
ter -
----
-->
Next Evaluation
Action #1
Actual Desired
Action #2
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Difficult Problems
Now Future
Bet
ter -
----
-->
Next Evaluation
Action #1
Action #2
ActualDesired
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Prevent ecological processes from taking control of
greenhouse gas emissions.
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The Climate Change System
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Potential Sources of Non-LinearityPositive 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
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Artic Ice Cover
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Ice Cover Feedback Loop
Ice Cover
Heat Reflected From Earth
Temperature Of the Air
Melting Of Ice
+
+
+
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Exercise on Action