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IPCC AR5 Synthesis Report

IPCC Fifth Assessment Report

Synthesis Report

Climatic Extremes and Disasters in Asia Vietnam

22nd January

IPCC AR5 Synthesis Report

Key Messages

➜ Human influence on the climate system is clear

➜ The more we disrupt our climate, the more we

risk severe, pervasive and irreversible impacts

➜ We have the means to limit climate change and

build a more prosperous, sustainable future

AR5 WGI SPM, AR5 WGII SPM, AR5 WGIII SPM

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IPCC AR5 Synthesis Report

Observed changes in the climate system

• The oceans have warmed and

risen

• The amounts of snow and ice

have diminished

• Sea level has risen

• The concentrations of greenhouse

gases have increased

Climate change is unequivocal

IPCC AR5 WGI

IPCC AR5 Synthesis Report

Some of the changes in extreme weather and climate events

observed since about 1950 have been linked to human influence

AR5 WGI SPM

Impacts are already

underway in a number of

regions:

• decrease in cold

temperature extremes

• increase in warm

temperature extremes

• increase in extreme

high sea levels

• increase in the number

of heavy precipitation

events

IPCC AR5 WGI

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IPCC AR5 Synthesis Report

Observed changes in Asia

• Increasing numbers of warm days and

decreasing numbers of cold days

• Precipitation trends including extremes are

characterized by strong variability

• Increasing and decreasing precipitation trends

in different parts and seasons of Asia

• Widespread damage to coral reefs linked with

episodes of high sea-surface temperature in

recent decades

• Asia experienced the highest number of

climate-related disasters in the world from

2000-2008 and suffered 27.5% of the total

global economic loss.

Warming trends and increasing temperature extremes have been observed

across most of the Asian region over the past century.

IPCC AR5 WGII

IPCC AR5 Synthesis Report

EXTREME EVENTS DURING AND BY THE END OF THE 21ST CENTURY

It is very likely that the length, frequency, and/or intensity of warm spells or

heat waves will increase over most land areas.

Under some scenarios, a 1-in-20 year hottest day is likely to become a 1-in-

2 year event in most regions.

It is likely that the frequency of heavy precipitation or the proportion of total

rainfall from heavy falls will increase over many areas of the globe.

IPCC SREX

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IPCC AR5 Synthesis Report

Abrupt and irreversible impacts

Most aspects of climate change will persist for many centuries even if

emissions of CO2 are stopped.

• Sustained mass loss by ice sheets

(some of which irreversible) would

cause larger sea level rise.

• Sustained warming greater than

some threshold (greater than about

1°C but less than about 4°C global mean warming with respect

to pre-industrial) would lead to the

near-complete loss of the

Greenland ice sheet over a

millennium or more, causing a

global mean sea level rise of up to

7 m.

IPCC AR5 WGII

IPCC AR5 Synthesis Report

Climate Change Poses Risk for Food Production

AR5 SYR SPM

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IPCC AR5 Synthesis Report

Impacts on human health

Throughout the 21st century, climate change is expected to lead to increases

in ill-health in many regions and especially in developing countries with low

income. Increased likelihood of:

• Injury, disease, and

death due to more

intense heat waves

and fires.

• Under-nutrition from

diminished food

production in poor

regions.

• Risks from food- and

water- and vector-

borne diseases.

IPCC AR5 WGII

IPCC AR5 Synthesis Report

Impacts on Human Security

Climate change over the 21st

century can increase:

• Displacement of people,

particularly in developing

countries with low income.

• Risks of violent conflicts by

amplifying poverty and

economic shocks.

• Rivalry among states due to

potential transboundary

impacts of climate change,

such as changes in sea ice,

shared water resources, and

pelagic fish stocks.

IPCC AR5 WGII

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IPCC AR5 Synthesis Report

Future risks of climate change in Asia

• Water scarcity is expected to be a major

challenge due to increased water demand

and lack of good management

• Higher temperatures can lead to lower rice

yields. A number of regions are already near

the heat stress limits for rice.

• Sea level rise will inundate low lying areas

and especially affect rice growing regions.

• Coastal and marine systems are under

increasing stress from climatic and non-

climatic drivers

• Damage to coral reefs will increase during

the 21st century as a result of ocean

warming and acidification.

IPCC AR5 WGII

IPCC AR5 Synthesis Report

Future risks of climate change in Asia

• Adverse effects on the

sustainable development

capabilities of most Asian

developing countries by

aggravating pressures on

natural resources and the

environment.

• Increasing impact of extreme

events on human health,

security, livelihoods, and

poverty, with the type and

magnitude of impact varying

across Asia.

IPCC AR5 WGII

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IPCC AR5 Synthesis Report

Climate-related hazards exacerbate other stressors, often with negative

outcomes for livelihoods, especially for people living in poverty.

Throughout the 21st century,

climate-change impacts are

projected to:

• Slow down economic growth

• Make poverty reduction

more difficult

• Further erode food security

• Prolong existing and create

new poverty traps,

particularly in urban areas

and emerging hotspots of

hunger

Implications for development:

IPCC AR5 WGII

IPCC AR5 Synthesis Report

Fatalities are higher in developing countries

From 1970-2008, over 95% of natural-disaster-related deaths occurred in

developing countries

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IPCC AR5 Synthesis Report

For exposed and vulnerable communities, even non-extreme

weather and climate events can have extreme impacts

 Africa’s largest recorded

cholera outbreak

• Over 90,000 affected

• Over 4,000 killed

• Began following onset of

seasonal rains

• Vulnerability

and exposure increased

risk

IPCC SREX

IPCC AR5 Synthesis Report

“Climate-resilient pathways combine adaptation and

mitigation to reduce climate change and its impacts. Since

mitigation reduces the rate and magnitude of warming, it

also increases the time available for adaptation to a

particular level of climate change, potentially by several

decades.”

Adaptation and Mitigation

IPCC Fifth Assessment Report

IPCC AR5 WGII

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IPCC AR5 Synthesis Report

There are strategies that can help manage disaster risk now and

also help improve people’s livelihoods and well-being

The most effective strategies offer development benefits in the

relatively near term and reduce vulnerability over the longer term.

IPCC SREX

IPCC AR5 Synthesis Report

Effective risk management and adaptation are tailored to local and

regional needs and circumstances

• Changes in climate extremes vary across regions

• Each region has unique vulnerabilities and exposure to hazards

• Effective risk management and adaptation address the factors contributing to exposure and

vulnerability

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IPCC AR5 Synthesis Report

Limiting Temperature Increase to 2˚C

Measures exist to achieve the substantial emission reductions required to limit

likely warming to 2°C (40-70% reduction in GHGs globally by 2050 and near zero or below emissions levels in 2100)

A combination of adaptation and substantial, sustained reductions in

greenhouse gas emissions can limit climate change risks

Implementing reductions in greenhouse gas emissions poses substantial

technological, economic, social, and institutional challenges

Ambitious mitigation is affordable and translates in