Synthesis in science and society – part A

Michael Raupach1,2

1Climate Change Institute, Australian National University, Canberra2Global Carbon Project, Future Earth

ACEAS Symposium, 7 May 2014

Thanks: colleagues in

• Institutional environments (CSIRO, ANU)

• International environments (Future Earth, Global Carbon Project)

• Project environments (Australia 2050, PMSEIC, AAS Climate Q&A)

Outline

Establishing the framework

• What is synthesis?

• Why attempt it?

Examples of synthesis

• Natural sciences: Climate changeThe Anthropocene

• Human sciences: Tragedy of the commons

• Contemporary challenge: Nature and humanity

A synthesis toolbox

• Traditional tools: observation, experiment, modelling

• Tools for synthesis: complexity, evolution, emergence, narratives

• Objective science and subjective values

• Synthesis as story: bridging between the objective and the subjective

What is synthesis?

“Seeing the big picture”

What is synthesis?

“Seeing the big picture”

Describing, understanding and governing a complex system

• Accounting for interactions between modular system elements

=> Modularity, hierarchyFocus on linkages more than on module-level detail

• Importance of defining the system and its boundary

=> What’s an external driver, what’s an internal response or feedback

What is synthesis?

“Seeing the big picture”

Describing, understanding and governing a complex system

• Accounting for interactions between modular system elements

=> Modularity, hierarchyFocus on linkages more than on module-level detail

• Importance of defining the system and its boundary

=> What’s an external driver, what’s an internal response or feedback

The current grand challenge: a synthesised perspective on nature and humanity as a single Earth System

Why attempt synthesis?

Antidote to reductionism?

• But reduction helps us modularise, so is essential for synthesis

Understanding the whole system is the challenge; understanding components is a means to that end

Many phenomena are emergent: they exist at system level but not component level a wave (sound, ocean, Mexican) weather, climate an ecosystem (structure, function) a human being (body, mind, spirit) a novel, poem, song, symphony, artwork a human society: health, wellbeing an economy climate change, sustainability

A holistic story has power: explanative, persuasive

Why attempt synthesis?

Antidote to reductionism?

• But reduction helps us modularise, so is essential for synthesis

Why attempt synthesis?

Antidote to reductionism?

• But reduction helps us modularise, so is essential for synthesis

Understanding the whole system is the challenge; understanding components is a means to that end

Why attempt synthesis?

Antidote to reductionism?

• But reduction helps us modularise, so is essential for synthesis

Understanding the whole system is the challenge; understanding components is a means to that end

Many phenomena are emergent: they exist at system level but not component level a wave (sound, ocean, Mexican) weather, climate an ecosystem (structure, function) a human being (body, mind, spirit) a novel, poem, song, symphony, artwork a human society: health, wellbeing an economy climate change, sustainability

Why attempt synthesis?

Antidote to reductionism?

• But reduction helps us modularise, so is essential for synthesis

Understanding the whole system is the challenge; understanding components is a means to that end

Many phenomena are emergent: they exist at system level but not component level a wave (sound, ocean, Mexican) weather, climate an ecosystem (structure, function) a human being (body, mind, spirit) a novel, poem, song, symphony, artwork a human society: health, wellbeing an economy climate change, sustainability

A holistic story has power: explanative, persuasive

Outline

Establishing the framework

• What is synthesis?

• Why attempt it?

Examples of synthesis

• Natural sciences: Climate changeThe Anthropocene

• Human sciences: Tragedy of the commons

• Contemporary challenge: Nature and humanity

A synthesis toolbox

• Traditional tools: observation, experiment, modelling

• Tools for synthesis: complexity, evolution, emergence, narratives

• Objective science and subjective values

• Synthesis as story: bridging between the objective and the subjective

Climate in the distant past (800,000 years)

Hansen et al. (2008)Target atmospheric CO2

Climate in the distant past (800,000 years)

Hansen et al. (2008)Target atmospheric CO2

Climate in the distant past (800,000 years)

Present CO2

Hansen et al. (2008)Target atmospheric CO2

Climate in the last 200 years

Greenhouse gas emissions

Greenhouse gas concentrations

Warming and other climate changes

0

2

4

6

8

10

1850 1890 1930 1970 2010

FF

em

iss

ion

s (

Pg

C/y

)280

300

320

340

360

380

400

1850 1890 1930 1970 2010A

tmo

sp

he

ric

CO

2 (

pp

m)

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1850 1890 1930 1970 2010

Te

mp

era

ture

(d

eg

C)

Cause

Effect 1

Effect 2

The climate system

Climate (temperature)

Adapted from: Australian Academy of Science (2010) The science of climate change: questions and answers

Solar radiation

Heat radiation

The climate system

Climate (temperature)

Adapted from: Australian Academy of Science (2010) The science of climate change: questions and answers

Solar radiation

Heat radiation

Aerosols

Water vapour, clouds

Ice sheets

GHGs(CO2, …)

Oceans

Biosphere

Human activities

The climate system

Climate (temperature)

Adapted from: Australian Academy of Science (2010) The science of climate change: questions and answers

Solar radiation

Heat radiation

Aerosols

Water vapour, clouds

Ice sheets

GHGs(CO2, …)

Oceans

Biosphere

Orbital variations

Volcanoes

Human activities

Many changes in climate

IPCC AR5 FOD TS Fig TS.1

Measures of changing global climate from 1850 to present

10 quantities

All available datasets are shown

Air temperature (land)

Air temperature (ocean)

Sea levelArctic sea-ice extent

Climate outlook: temperatureWarming of 2 to 5 degrees above preindustrial (strong to minimal mitigation)

IPCC (2013) Fifth Assessment, Working Group 1

Climate models: future global warming and precipitation

Diffenbaugh and Field (2013) Science 341, 486-492

Warming

More warming in high latitudes (polar amplification) – already observed

Change in precipitation

Increase in global precipitation (and global evaporation)

Changes are highly non-uniform: predicted drying in mid-latitudes

IPCC (2013) AR5 WG2 SPM

Food securityClimate change will reduce wheat and maize yields by 1-2% per decade

PMSEIC 2010) Australia and food security

Target

Trend

Food securityImplications of climate change for global cereal production

Projected global cereal production

• 10% below target without climate change

• 15-25% below target with climate change

IPCC (2013) AR5 WG2 SPM

Ecosystem changesMarine organisms are moving into previously colder waters

IPCC (2013) AR5 WG2 SPM

Ecosystem changesClimate zones will faster than many land species can shift habitat

Future emissions scenarios and their consequences

To have a 50% chance of keeping warming below 2 deg (relative to preindustrial), global emissions must be halved by 2050 (relative to 2000)

> 4 deg

2 deg

Global CO2 emissions from fossil fuels are tracking the highest scenarioF

ossi

l fue

l CO

2 em

issi

ons

[PgC

/y]

Scenarios: IPCC Representative Concentration Pathways

Observation uncertainty band (± 1 standard deviation)

Data: Global Carbon Project 2014 (Le Quéré et al 2014)

Warming is approximately proportional to cumulative CO2 emissions

Warming is approximately proportional to cumulative CO2 emissions

Reinforcing feedbacks:• Ice-albedo• Carbon cycle• Ecosystem

collapse

Stabilising feedbacks:• Heat loss (Planck)• CO2 removal by carbon sinks• Logarithmic response to CO2

Sharing the cumulative emissions pie

w=0.0

USAEuropeJapanD1FSUChinaIndiaD2D3

Inertia: share by current or historic emissions

USADeveloping

China

Sharing the cumulative emissions pie

w=0.0

USAEuropeJapanD1FSUChinaIndiaD2D3

w=1.0

USAEuropeJapanD1FSUChinaIndiaD2D3

Inertia: share by current or historic emissions

Equity: share by

population

USADeveloping USA

Developing

China China

Sharing the cumulative emissions pie

w=0.0

USAEuropeJapanD1FSUChinaIndiaD2D3

w=1.0

USAEuropeJapanD1FSUChinaIndiaD2D3

w=0.5

Inertia: share by current or historic emissions

Equity: share by

population

Compromise: share by mixture of

emissions and population

weight w (0 to 1) is a “sharing index"w=0 w=1

USADeveloping USA

Developing

China China

Tragedy of the commons, and beyond

Hardin (1968) - model of herders on a common pasture - problem has no purely technical fix

Dietz, Ostrom and Stern (2003):

• Tragedy-of-commons problems can be solved with adaptive governance in complex systems

• Requires: InformationConflict resolutionRule complianceInfrastructureReadiness for change

• These factors need to act at compatible scales

Pretty (2003):

• natural, physical, financial, human, social capital

• social capital is a prerequisite for collective resource management

Hardin G (1968) The tragedy of the commons. Science 162, 1243.

Dietz T, Ostrom E, Stern PC (2003) The struggle to govern the commons. Science 302.

Pretty J (2003) Social capital and the collective mangement of resources. Science 302.

Reprinted in Kennedy D et al. (2006) Science Magazine's State of the Planet 2006-2007. Island Press, Washington DC.

Outline

Establishing the framework

• What is synthesis?

• Why attempt it?

Examples of synthesis

• Natural sciences: Climate changeThe Anthropocene

• Human sciences: Tragedy of the commons

• Contemporary challenge: Nature and humanity

A synthesis toolbox

• Traditional tools: observation, experiment, modelling

• Tools for synthesis: complexity, evolution, emergence, narratives

• Objective science and subjective values

• Synthesis as story: bridging between the objective and the subjective