IPCC AR5 Synthesis Report

Presentation of the IPCC Fifth Assessment Report

23rd February

Key Messages of the IPCC AR5Nairobi, Kenya

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

Oceans absorb most of the heat

➜ More than 90% of the energy accumulating in the climate system between 1971 and 2010 has accumulated in the ocean

➜ Land temperatures remain at historic highs while ocean temperatures continue to climb AR5 SYR

It is extremely likely that human influence has been the dominant

cause of warming since the mid-20th century

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• Surface temperatures have

increased by 0.5°C or more

during the last 50-100 years over

most parts of Africa.

• Surface temperature anomalies in

Africa were significantly higher for

the period 1995–2010 compared to

the period 1979–1994.

• Increase in seasonal mean

temperature in many areas of

Ethiopia, Kenya, South Sudan, and

Uganda over the last 50 years.

Evidence of warming over land regions across Africa, consistent with

anthropogenic climate change, has increased

AR5 WGII

Observed and projected changes in annual average temperature

AR5 WGII Fig 22-1

Observed and projected changes in annual average precipitation

AR5 WGII Fig 22-1

Anthropogenic GHG emissions have increased since the pre-industrial era, driven

largely by economic and population growth, and are now higher than ever.

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The atmospheric concentrations of carbon dioxide, methane and nitrous

oxide that are unprecedented in at least the last 800,000 years.

Sources of emissions

Energy production remains the primary driver of GHG emissions

35%24% 21% 14%

6.4%

2010 GHG emissions

Energy Sector

Agriculture,

forests and

other land uses

Industry Transport

Building

Sector

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AR5 WGII Fig 22-3 (a) Confidence in detection and in attribution of observed climate change over

Africa to anthropogenic emissions. (b) Confidence in detection and in attribution of the impacts of observed regional climate change on various African systems.

Some of the changes in extreme weather and climate events

observed since about 1950 have been linked to human influence

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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

Projected climate changes

Continued emissions of greenhouse gases will cause further

warming and changes in the climate system

Global glacier volume will further decrease

Global mean sea level will continue to rise during the 21st century

It is very likely that the Arctic sea ice cover will continue to shrink and thin as global mean surface temperature rises

Oceans will continue to warm during the 21st century

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Potential Impacts of Climate Change

Food and water shortages

Increased poverty

Increased displacement of people

Coastal flooding

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Climate Change Poses Risk for Food Production

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African ecosystems are already being affected by climate change, and future impacts are expected to be substantial

• Temperatures in Africa are projected to rise

faster than the global average increase during

the 21st Century,

• Under a high RCP, an exceedence of 2°C could

occur by mid-century across much of Africa and

reach between 3 and 6°C by the end of the

Century.

• Ocean ecosystems, in particular coral reefs, will

be affected by ocean acidification and warming,

thus negatively affecting economic sectors such

as fisheries.

• Climate change will amplify existing stress on

water availability in Africa.

• Increasing temperatures and changes in

precipitation are very likely to reduce cereal crop

productivity. This will have strong adverse effects

on food security.

AR5 WGII

Figure SYR SPM.10,

A reader’s guide

From climate change risks to GHG emissions

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 into delayed but not foregone

growth (economic growth reduced by ~ 0.06% / BAU growth 1.6-3%). Estimated

costs do not account for the benefits of reduced climate change

AR5 WGI SPM, AR5 WGII SPM,AR5 WGIII SPM

But delaying mitigation will substantially increase the challenges associated

with limiting warming to 2°C

Adaptation Experience in Africa

Since 2007, Africa has gained experience in

planning and beginning to implement

adaptation activities, from local to national

levels and across a growing range of sectors.

However, across the continent, most of the

adaptation is reactive in response to short-

term motivations, is occurring at the

individual/household level, and lacks support

from government.

Africa’s urgent adaptation needs stem from

the continent’s foremost sensitivity and

vulnerability to climate change, together with

its low levels of adaptive capacity.

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Inherent adaptation-related strengths in Africa include:

• The continent’s wealth in natural

resources

• Well-developed social networks

• Longstanding traditional

mechanisms of managing variability

through, for example, crop and

livelihood diversification, migration,

and small-scale enterprises,

• Local or indigenous knowledge

systems for sustainable resource

management

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Adaptation needs in Africa

Since Africa is extensively exposed

to a range of multiple stressors that interact

with longer term climate change,

adaptation needs are broad,

encompassing:

• Institutional, social, physical, and

infrastructure needs

• Ecosystem services and environmental

needs

• Financial and capacity needs

• Making climate change information

more reliable and accessible is one of

the most pressing and cross-cutting

adaptation needs

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Mitigation Measures

More efficient use of energy

Greater use of low-carbon and no-carbon energy• Many of these technologies exist today

• Nearly a quadrupling of zero- and low-carbon energy supply

from renewable energy by 2050

Improved carbon sinks• Reduced deforestation and improved forest management

and planting of new forests

• Bio-energy with carbon capture and storage

Lifestyle and behavioural changesAR5 WGIII SPM

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“…stabilization of GHG concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system…” ~ Article 2 of the UNFCCC

Very likely more intense and

frequent extreme precipitation

events in many regions.

A likely nearly ice-free Arctic

Ocean in September before

mid-century (RCP8.5).

Very likely that global sea-level

rise will continue in the 21st

century (0.26-0.55m in RCP2.6

/ 0.45-0.82m in RCP8.5).

Projections of reductions of

renewable surface- and

groundwater resources in

some regions.

Projections of increasing

displacement of people, and

risks of violent conflicts.

The risk associated with

crossing certain thresholds

increases with rising

temperatures.

Effective decision making to limit climate change recognizes the importance of

ethical dimensions, equity, value judgments, economic assessments, and diverse

perceptions and responses to risk and uncertainty.

Climate change and equity

Issues of equity, justice, and fairness arise

with respect to mitigation and adaptation:

• Different past and future contributions to

the accumulation of GHGs in the

atmosphere

• Varying challenges and circumstances

• Different capacities to address mitigation

and adaptation.

Options for equitable burden-sharing can

reduce the potential for the costs of climate

action to constrain development.

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The window for action is rapidly closing

65% of our carbon budget compatible with a 2°C goal already used

Amount Used

1870-2011:

1900GtCO2

Amount

Remaining:

1000GtCO2

Total Carbon

Budget:

2900GtCO2

AR5 WGI SPM

IPCC AR5 Synthesis Report

IPCC Fifth Assessment Report