Global Climate Change

[Econ 2277](http://www.richard-sweeney.com/intro_env_econ)
[Prof. Richard L. Sweeney](http://www.richard-sweeney.com/)

[(print this presentation)](http://www.richard-sweeney.com/intro_env_econ/slides/ClimateChange.html?print-pdf)


Overview of next two weeks


Climate change is happening

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Global combined land and ocean surface temperature anomalies relative to the average from 1986 to 2005. (IPCC 2014)


Climate change is happening

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Annually and globally averaged sea level change relative to the average from 1986 to 2005. (Source: IPCC Synthesis Report 2014)


Trend concurrent with dramatic increase in CO2

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Well known physical relationship

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Source


Humans are causing it


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Things are going to get worse if we don’t act

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Things are going to get worse if we don’t act

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Current CO2 equiv. concentrations $\approx$450 ppm


Recent IPCC report predicts dire consequences







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NOAA: “a sea level rise of 2 feet would more than triple the frequency of coastal flooding across the Northeast, without any change in storms.”


What are we doing about it?

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Emissions path under to 2030 under COP21 Commitments Source: IEA WEO Special Report 2015


Recent IPCC report concludes drastic action needed



Basic outline of a solution is well known


Good news

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Bad news: Non-hyro renewables less than 5\% of global consumption


Challenge #1: Timing and Intermittency

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Challenge #2: Renewables low energy-density


Costs of avoiding 450 ppm is manageable (but not trivial)

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The main challenges are political, not technical


Challenge #1: CO2 is a uniformly mixing pollutant


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Challenge #2: CO2 is a stock pollutant

Economic implication: “Solving climate change is a like marathon, not a sprint”


Challenge #3: Outcomes and damages are uncertain

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Climate sensitivity parameter = average surface warming resulting from a doubling of CO2, in equilibrium

Source: Heal and Miller 2014


Geoengineering


Proof of concept: 1991 Mt. Pinatubo eruption (Phillipines)


Adaptation

Required Readings

Stavins 2013
IPCC Special Report [link]
US 4th National Assessment [link]