Presentation by
Renate Christ, Secretary of the IPCC
Geneva, 22 October 2008

A Progression of Understanding: Greater and Greater
Certainty in Attribution to Human Influence
FAR (1990): “unequivocal detection not likely for a decade”
SAR (1995): “balance of evidence suggests discernible human influence”
TAR (2001): “most of the warming of the past 50 years is likely
(odds 2 out of 3) due to human activities”
AR4 (2007): “ most of the warming is very likely
(odds 9 out of 10) due to anthropogenic greenhouse gases ”
FAR
SAR
TAR
AR4
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Distribution of regional per capita
GHG emissions in 2004
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Surface Warming Pattern
A1B, 2090-2099 relative to 1980-1999
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High latitude:
- production increases with 1-3 °C rise in local mean temperature
- decreases above 1-3 °C rise.
Low latitude:
- Production decreases with 1-2
°
C rise in local mean temperatures
- Increased drought/flood frequency affect especially subsistence sectors at low latitudes
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Impacts on crops and lifestock

Projected impacts on water resources
By mid-century river runoff and water availability
- increase by 10-40% at high latitudes, some wet tropics
- decrease by 10-30% over dry mid-latitudes and dry tropics
Drought-affected areas will likely increase in extent.
More heavy precipitation events will augment flood risk.
In the course of the century, water supplies stored in glaciers and snow cover are projected to decline, reducing water availability in regions where more than one-sixth of the world population currently lives.
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Climate change could impede nations’ abilities to achieve sustainable development

Human settlements and low-lying areas
Risks associated with extreme events
- High vulnerability in riverine and coastal areas
- Urbanization often in high risk areas
- Millions of people could experience more coastal flooding if Δ T > 2 o C in this century.
- Impacts exacerbated by storms, coral bleaching, degradation of coastal wetlands and increased human-induced pressures
Sea level rise is inevitable !
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Megadeltas – particularly vulnerable

The health status of millions of people is projected to be affected
• Increases in malnutrition
• Increased deaths, diseases and injury due to extreme weather events
• Increased burden of diarrhoeal diseases
• Increased frequency of cardio-respiratory diseases due to changes in air quality
• Altered spatial distribution of some infectious diseases.
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- Sharp differences across regions
- Low-latitude and less-developed areas generally face greater risk
- Those in weakest economic position are often the most vulnerable to climate change
- Greater vulnerability of specific groups such as poor and elderly - also in developed countries
Multiple non-climate stresses increase vulnerability
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Analytical Tools
• Scenario driven impacts analysis
• Provides broad overview
• Vulnerability assessment
• Broadened to include social vulnerability
• Adaptation based approach
• Examine adaptive capacity and improve resilience
• Key vulnerabilities – long term goal Art.2 UNFCCC
• Magnitude, timing, persistence and reversibility, likelihood of occurrence, potential for adaptation, distribution of impacts and importance of system at risk

Risk-management framework
Risk - defined by magnitude and probability of occurrence
Captures
• uncertainty
• exposure
• sensitivity
• adaptation

Risk-management framework
• Assignment of probabilities to specific key impacts – can be very difficult
• Mitigation reduces risks, delay in action increases risks
• Adaptation reduces risk of negative impacts
• More difficult to adapt to larger magnitudes and faster rates of warming
• Some impacts cannot be avoided – sea level rise, loss of species
• Climate change in context of socio-economic baseline

Vulnerability, adaptation and mitigation

GHG Stabilization and Temperature
The lower the stabilization, the earlier global GHG should go down
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Impacts by sector

Way forward
• Identify vulnerable areas and communities
• Identify driving forces that enhance or reduce vulnerability
• Develop adaptation plans – bottom up and top down, use local coping capacity
• Analysis of synergies and trade-offs of adaptation and mitigation measures – on case by case basis
• Food prices, degradation of natural habitat, employment,
• Assessment of attribution of damages and of avoided damages
• Address question of insurance

Nobel Peace Prize 2007
IPCC together with Mr Gore
« for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change"