BROWN UNIVERSITYEnvironmental Change Initiative

Global Climate Change: What’s Different Now?

Marty DownsAssistant Director

Environmental Change InitiativeBrown University

Leadership and Global EngagementAugust 6, 2008

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Climate change is not new…

…and in some ways is very simple

FAQ 2.1, Figure 1

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But it can be complicated

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What prevented acceptance and action?

• Uncertainties in the science

• Perceived as gradual and benign

• Attributed to natural causes

• Different effects in different places

• Effective action had to be concerted– For individuals– For industries – For countries

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Changing Scientific Understanding

IPCC AR4 WG1 Figure 1.2 IPCC AR4 WG1 Figure 1.4

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Perceived as gradual and benign, but feedbacks could be sudden and unpredictable

Larsen Ice Shelf off Antarctica 2002Credit:NASA/Goddard Space Flight Center

Tundra warming experimentsCredit: Jason Orfanon, National Geographic

Ocean “conveyor belt” Credit: US Global Change Research Program

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Maybe it’s real, but it would have happened anyway

Figure SPM.4IPCC AR4. Summary for Policymakers. Figure 4

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Effects will be different in different places…

UNEP/GRID-Arendal. Precipitation changes: trends over land from 1900 to 2000. UNEP/GRID-Arendal Maps and Graphics Library. 2005. Available at: http://maps.grida.no/go/graphic/precipitation_changes_trends_over_land_from_1900_to_2000. Accessed August 05, 2008.

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…leading to different impacts

UNEP/GRID-Arendal. Projected agriculture in 2080 due to climate change. UNEP/GRID-Arendal Maps and Graphics Library. 2008. Available at: http://maps.grida.no/go/graphic/projected-agriculture-in-2080-due-to-climate-change. Accessed August 05, 2008.

Agriculture

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UNEP/GRID-Arendal. Climate change and Malaria, scenario for 2050. UNEP/GRID-Arendal Maps and Graphics Library. 2005. Available at: http://maps.grida.no/go/graphic/climate_change_and_malaria_scenario_for_2050. Accessed August 05, 2008.

…different vulnerabilities

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And some places are more vulnerable than others

• food import dependency ratio• water scarcity• energy imports as percentage of consumption• access to safe water• expenditures on defense versus health and education• human freedoms• urban population growth• child mortality• maternal mortality• income per capita• degree of democratization• fertility rates.

Millenium Ecosystem AssessmentFigure 6.2. Vulnerability Index for African Countries (Lonergan 1998)

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UNEP/GRID-Arendal. Carbon inventory. UNEP/GRID-Arendal Maps and Graphics Library. 2008. Available at: http://maps.grida.no/go/graphic/carbon-inventory. Accessed August 05, 2008.

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…and different priorities

UNEP/GRID-Arendal. Trends in natural disasters. UNEP/GRID-Arendal Maps and Graphics Library. 2005. Available at: http://maps.grida.no/go/graphic/trends-in-natural-disasters. Accessed August 05, 2008.

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Addressing climate change requires broad participation and pervasive change

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So what happened?

• Consensus: IPCC – Al Gore

• Demonstration: Katrina –Pacific

Cyclones

• Insurance industry: rising re-insurance

costs

• The business case: maybe there’s a

way to make money

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What next?