Climate Change: General Introduction (Basic Introduction for Students with Some Science Knowledge)...

Climate Change: General Introduction(Basic Introduction for Students with

Some Science Knowledge)

Richard B. RoodCell: 301-526-8572

2525 Space Research Building (North Campus)rbrood@umich.edu

http://aoss.engin.umich.edu/people/rbrood

September 30, 2015

Getting Started

• Rood Blog “Just Temperature”

• Rood The Conversation “30 Years”

November 2013: Global Temperature

August 2015: Global Temperature

Overview

• Climate Change in a Nutshell• Climate-Energy-Policy Interface

Some Basic References

• Intergovernmental Panel on Climate Change– IPCC (2007) Working Group 1: Summary for Policy Makers– IPCC (2013) Working Group 1: Summary for Policy Makers

• Spencer Weart: The Discovery of Global Warming• Carbon dioxide greenhouse effect:

http://www.aip.org/history/climate/co2.htm• Simple climate models

http://www.aip.org/history/climate/simple.htm• Paul Edwards: A Vast Machine• Rood

– Rood Climate Change Class

Naomi Oreskes, Why Global Warming Scientists are Not Wrong

Climate Change in a Nutshell

• How and what do we know?• Increase of carbon dioxide• Some predictions• Some observations (and attribution)• How do we organize our responses?• Reading about 4 degrees of warming

– New et al. 2010, Phil. Trans. Roy. Soc.

Starting point: Scientific foundation

• The scientific foundation of our understanding of the Earth’s climate is based on budgets of energy, mass, and momentum. (Conservation principles)

• The scientific foundation of our understanding of the Earth’s climate is based on an enormous and diverse number of observations.

Starting point: A fundamental conclusion

• Based on the scientific foundation of our understanding of the Earth’s climate, we observe that with virtual certainty– The average global temperature of the Earth’s

surface has increased due to the addition of gases into the atmosphere that hold heat close to the surface. The increase in greenhouse gases is due to human activities, especially, burning fossil fuels.

Starting point: A fundamental conclusion

• Based on the scientific foundation of our understanding of the Earth’s climate, we predict with virtual certainty– The average global temperature of the Earth’s surface

will continue to rise because due to the continuing addition of gases into the atmosphere that hold heat close to the surface. The increase in greenhouse gases is due to human activities, especially, burning fossil fuels.

– Historically stable masses of ice on land will melt.– Sea level will rise.– The weather will change.

Scientific Approach

• Climate science is observationally based• Climate change is computational science

– Relies on models

Models are an Important Part of Climate ScienceWhat is a Model?

• Model– A work or construction used in testing or perfecting a

final product.– A schematic description of a system, theory, or

phenomenon that accounts for its known or inferred properties and may be used for further studies of its characteristics.

• Numerical Experimentation– Given what we know, can we predict what will

happen, and verify that what we predicted would happen, happened?

Scientific Investigation

OBSERVATIONS THEORY

PREDICTION

Past FuturePresent

Understanding ProcessesEvaluation, Verification

Predictions Projections

Time

Summary Points: Science

Theory / Empirical EvidenceCO2 and Water Vapor Hold Heat Near

Surface

Correlated ObservationsCO2 and Temperature Observed to be strongly related on long time scales (>

100 years) CO2 and Temperature not Observed to be strongly related on short time scales (<

10 years)

ObservationsCO2 is Increasing due to Burning Fossil

Fuels

Theory / Conservation PrincipleMass and Energy Budgets

Concept of “Forcing”

Prediction Earth Will

Warm

ValidationEvaluation

Consequences

Land Use / Land ChangeOther Greenhouse GasesAerosolsInternal Variability

Feedbacks

Air Quality“Abrupt” Climate Change

Conservation principle: Energy

Energy from the Sun

Energy emitted by Earth(proportional to T)

Earth at a certain temperature, T

Stable Temperature of Earth could change from how much energy (production) comes from the sun, or by changing how we emit energy.

The first place that we apply the conservation principle is energy

• We reach a new equilibrium

HT

THt

T

LossProduction

-0

The first place that we apply the conservation principle is energy

• We reach a new equilibrium

HT

THt

T

LossProduction

-0

Changes in orbit or solar energy changes this

Conservation principle: Energy

Energy from the Sun

Earth at a certain temperature, T

Add some detail:

SurfaceInsulating Blanket

The first place that we apply the conservation principle is energy

• We reach a new equilibrium

HT

THt

T

LossProduction

-0

Changing a greenhouse gas changes this

Some basics

Observed Increase of Atmospheric Carbon Dioxide (CO2)

Data and more information

Primary increase comes from burning fossil fuels – coal, oil, natural gas

The yearly cycle of CO2

Presentation of some results

• These are drawn from the Reports of the Intergovernmental Panel on Climate Change. I deliberately mix graphs from reports in 2001, 2007, and 2013. The messages from these reports are quite similar, which is a measure of – Consistent measure– Stable scientific understanding

IPCC (2007) projections for the next 100 years.

Projected Global Temperature Trends: 2100

2071-2100 temperatures relative to 1961-1990.Special Report on Emissions Scenarios Storyline B2 (middle of the road warming).

IPCC 2001

Observed Temperature Anomaly in 2005http://data.giss.nasa.gov/gistemp/2005/

See Also: Osborn et al., The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years, Science, 311, 841-844, 2006

IPCC 2013: Observed Temperature

Rood: What would happen if we stopped emitting now?

What does this mean for design and engineering?

IPCC 2007: The last

~100 years

Fig. 2.5. (State of Climate 2009) Time series from a range of indicators that

would be expected to correlate strongly with the surface record.

Note that stratospheric cooling is an expected consequence of greenhouse gas increases. A version of this figure

with full references is available at www.ncdc.noaa.gov/bams-state-of-climate/ .

Correlated behavior of different parameters

Quick Summary: IPCC(2013)

Length of Growing Season

From Ranga B. Myneni, Boston University

Summary In Progress: Observations

• Observations of climate change (global warming)– Average surface temperature of planet is increasing– Ice is melting

• Glaciers• Ice sheets

– Sea level is rising• Ocean is warming up• From the melting ice

– Weather is changing• Coherent and convergent evidence

Summary In Progress: Projections

• Observations are consistent model projections– Past century– Evolving

• Model projections– Planet will warm– Ice will melt– Sea level will rise– Weather will change

Summary In Progress: Uncertainty

• Identified major categories of uncertainty– Scenario – future emissions– Model – deficiencies in simulation capability– Observational – quality of observations,

inability to completely observe– Dynamic variability – internal variability due to

transfer of energy between components of a complex system

Summary in Progress: Attribution

• Have suggested several aspects of extent and attribution of warming to greenhouse gases– Spatial distribution of warming– Decrease of temperature in the stratosphere– Changes in growing season– Changes in seasonal cycle of carbon dioxide– Warming in the ocean– ….

What parameters/events do we care about?

• Temperature• Water

– Precipitation– Evaporation– Humidity

• Air Composition– Air quality– Aerosols– Carbon dioxide

• Winds• Clouds / Sunlight

• Droughts• Floods

• Extreme Weather

The impact of climate change is Water for EcosystemsWater for PeopleWater for EnergyWater for Physical Climate

Science, Mitigation, Adaptation Framework

Mitigation is controlling the amount of CO2 we put in the atmosphere.

Adaptation is responding to changes that might occur from added CO2

It’s

not

an

eith

er /

or

argu

men

t.

Some Points

• Science-based conclusions– The surface of the Earth has warmed and this

warming is consistent with increasing greenhouse gases. CO2 is most important.

– The Earth will continue to warm.– The concept of “stabilization” of CO2 is

challenged by the consideration of ocean-land-atmosphere time scales• Accumulated carbon dioxide is important. • 1 trillion tons 440 ppm

Break

Climate-Energy-Policy Interface

• Problem solving: Reduction of complexity• Policy (global): Goals• Climate-Energy-Population-Consumption• Notional Solution Strategy

Responses to the Climate Change Problem

Autonomous/Individual

Policy/Societal

Reactive Anticipatory

Adaptation Mitigation

Stabilization / Total burden of Greenhouse Gases

• Have this notion of controlling emissions to stabilize the concentration of CO2 in the atmosphere at some value.– That is, there was some value of emissions that would match the

loss of CO2 into the plants, soil and oceans.

– However, CO2 is exchanged between plants, soil and ocean, and it takes a very long time for CO2 amounts to decline.

• We know that the CO2 that we emit will be with us essentially forever. Therefore, it is the total amount that we emit, rather than controlling emissions.– Arguably, we get to emit 1 trillion tons before climate change is

“dangerous”– “Dangerous” = 2 degrees C average surface warming

What is short-term and long-term?

25 years 50 years 75 years 100 years0 years

ENERGY SECURITY

ECONOMYCLIMATE CHANGE

Pose that time scales for addressing climate change as a society are best defined by human dimensions. Length of infrastructure investment, accumulation of wealth over a lifetime, ...

LONGSHORT

There are short-term issues important to climate change.

Election time

scales

Managing Climate Complexity

TEMPORAL

NEAR-TERM LONG-TERM

SPATIAL

LOCAL

GLOBAL

WEALTH

Managing Climate Complexity

TEMPORAL

NEAR-TERM LONG-TERM

SPATIAL

LOCAL

GLOBAL

WEALTH

Being Global, Long Term, Wealth connected, degree of difficulty is high

Framework Convention on Climate Change

The Rationalist and Policy

• Determine what is a tolerable ceiling for carbon dioxide.- Gives cap for a cap and trade system.- Tolerable ceilings have been posed as between 450

and 550 ppm.- Ice sheet melting and sea level?- Oceanic circulation / The Gulf Stream?- Ocean acidification?

- Determine a tolerable measure of increased temperature- Copenhagen Accord (2009) 2o C

A trillion tons of carbon

• We get to emit a trillion tons of carbon to avoid “dangerous” climate change

• Where does mitigation, reduction of emissions fit on the spatial and temporal scales?

Trillion Tons: Carbon Visuals

Mainstream approach – targets and timetables

From R. Pielke Jr. The Climate Fix

Climate Change Relationships

• We have a clear relationship between energy use and climate change.

CLIMATE CHANGE ENERGY

The build up of carbon dioxide is directly related to combustion of fossil fuels: coal, oil, natural gas

Context: Energy and Climate Change

• Consumption // Population // Energy

CLIMATE CHANGE

ENERGY

POPULATION

CONSUMPTION

SO

CIE

TAL

SU

CC

ES

S

Have to manage, eliminate the waste of energy production

People

Engage in economic activity that

Uses energy from

Carbon emitting generation

Population

GDP per person

Energy intensity of the economy

Carbon intensity of energy

P

GDP/P

TE/GDP

C/TE

Carbon emissions = C = P * GDP * TE * C ------ ---- ---- P GDP TE

Where do emissions come from?

The “Kaya Identity” see IPCC WG 3

From R. Pielke Jr. The Climate Fix

Less people

Smaller economy

Increase efficiency

Switch energy sources

Population management

Limit generation of wealth

Do same or more with less energy

Generate energy with less emissions

Carbon emissions = C = P * GDP * TE * C ------ ---- ---- P GDP TE

Factor LeverPopulation

GDP per person

Energy intensity

Carbon intensity

Approach to Policy

GDPTechnology

P

GDP/P

TE/GDP

C/TE

What tools do we have to reduce emissions?

From R. Pielke Jr. The Climate Fix

So why has energy consumption increased so much?

• GDP/person is considered the “societal success”

• Energy use increases have been driven by growth in population and GDP/person.

Energy use = (population)*(GDP/person) *(energy/unit GDP)

Pielke Jr. argues

• The need for technology to make solutions possible.

• Inequity of wealth, access to basic resources, desire for economic growth makes energy use an imperative

• Must go– From, we use too much energy, fossil fuels are cheap– To, we need more energy, fossil fuels are expensive

Past Emissions

Princeton Carbon Mitigation Initiative

The Stabilization Triangle

Princeton Carbon Mitigation Initiative

The Wedge Concept

Princeton Carbon Mitigation Initiative

Stabilization (2006)

Princeton Carbon Mitigation Initiative

CO2 stabilization trajectory (2006)

• Stabilize at < 550 ppm. Pre-industrial: 275 ppm, current: ~400 ppm.

• Need 7 ‘wedges’ of prevented CO2 emissions.

Princeton Carbon Mitigation Initiative

Some Points

• Analysis and Opinion – Probability of stabilizing at less than 440, 560 … ppm

is very small.• If we decide to stabilize at 350, 440, then we need

to figure out how to remove CO2 from the atmosphere.

Some Points

• Analysis and Opinion – We need to start to plan for a world that is on

average, warmer than the 2 degrees C that we have deemed as the threshold of “dangerous”.

– We have an enormous opportunity provided by predictions of climate change. We have the choice of whether or not to take advantage of this opportunity on personal, professional, local, national, and international levels.• The world 4 degrees warmer: January 13, 2011 issue of

The Philosophical Transactions of the Royal Society

Some Other References for the Interested

• Rood– Rood Blog “Just Temperature”– Rood Blog: Arctic Oscillation and Cold Times in Easte

rn North America– Rood Blog: Trillion Tons of Carbon Dioxide– Rood Blog: Warming Hiatus

• Lemos and Rood (2010)• Koshland Science Museum: Global Warming

Backup Slides

Resources and Recommended Reading

• Stern Report: Primary Web Page• Stern Report: Executive Summary

• Nordhaus: Criticism of Stern Report• Tol and Yohe: Deconstruction of Stern Rep

ort

Some carry away messages

• Determine what is a tolerable ceiling for carbon dioxide.- Gives cap for a cap and trade system.- Tolerable ceilings have been posed as between 450

and 550 ppm.- Ice sheet melting and sea level?- Oceanic circulation / The Gulf Stream?- Ocean acidification?

- Determine a tolerable measure of increased temperature- Copenhagen Accord (2009) 2o C

Dangerous climate change?

Stern, 2006

World 4 Degrees Warmer

Stern, 2006

McKinsey 2007