IPCC AR5 Synthesis Report
IPCC Fifth Assessment Report
Synthesis Report Jan Fuglestvedt, CICERO
Karen O’Brien, University of Oslo
Working Group I WGI
Working Group II WGII
Working Group III WGIII
Synthesis Report
Bredt og åpent internasjonalt samarbeid
Bredt og åpent internasjonalt samarbeid
IPCC AR5 Synthesis Report
AR5 SYR SPM
IPCC AR5 Synthesis Report
AR5 SYR SPM
IPCC AR5 Synthesis Report
AR5 SYR SPM
IPCC AR5 Synthesis Report
AR5 SYR SPM
More recent data (1970-2010) and other gases than CO2
What factors have driven emission changes?
IPCC AR5 Synthesis Report
Sources of emissions
Energy production remains the primary sources of GHG emissions
35% 24% 21% 14%
6.4%
2010 GHG emissions
Energy Sector
Agriculture,
forests and
other land uses
Industry Transport
Building
Sector
AR5 WGIII SPM
IPCC AR5 Synthesis Report
Causes of climate change
IPCC AR5 Synthesis Report
IPCC AR5 Synthesis Report
IPCC AR5 Synthesis Report
IPCC AR5 Synthesis Report
Causes of climate change
Anthropogenic greenhouse gas emissions have
increased since the pre-industrial era, driven
largely by economic and population growth, and
are now higher than ever.
Their effects, together with those of other
anthropogenic drivers, have been detected
throughout the climate system and are extremely
likely to have been the dominant cause of the
observed warming since the mid-20th century.
IPCC AR5 Synthesis Report
Impacts are already underway
• Tropics to the poles
• On all continents and in the ocean
• Affecting rich and poor countries
AR5 WGII SPM
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
IPCC AR5 Synthesis Report
What is happening in Norway?
IPCC AR5 Synthesis Report
What about the future?
IPCC AR5 Synthesis Report
Projected climate changes
Continued emissions of greenhouse gases will cause
further warming and changes in the climate system
AR5 WGI SPM
IPCC AR5 Synthesis Report
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
Ocean acidification will continue.
IPCC AR5 Synthesis Report
Potential Impacts of Climate Change
• Risk of severe ill-health and disrupted livelihoods;
• Systemic risks due to extreme weather events;
• Risk of loss of ecosystems, biodiversity, and
ecosystem goods, functions and services;
• Risk of food and water insecurity. AR5 WGII SPM
IPCC AR5 Synthesis Report
Climate Change Poses Risk for Food Production
AR5 SYR SPM
IPCC AR5 Synthesis Report
Adaptation to climate change
Adaptation can reduce the risks of climate change
impacts, but there are limits to its effectiveness.
Some adaptation responses involve significant
co-benefits, synergies, and trade-offs.
Increasing climate change will increase
challenges for many adaptation options.
AR5 WGI SPM, AR5 WGII SPM,AR5 WGIII SPM
IPCC AR5 Synthesis Report
We need both adaptation and mitigation
AR5 WGIII SPM
Effective adaptation and mitigation responses will depend on policies and measures across multiple scales: regional, national and sub-national.
Adaptation and mitigation responses are underpinned by common enabling factors
IPCC AR5 Synthesis Report
IPCC AR5 Synthesis Report
Limiting Temperature Increase to 2˚C
Measures exist to achieve the substantial emissions
reductions required to limit likely warming to 2°C
Implementing reductions in GHG emissions poses
substantial technological, economic, social, and
institutional challenges
But delaying mitigation will substantially increase the
challenges associated with limiting warming to 2°C
AR5 WGI SPM, AR5 WGII SPM,AR5 WGIII SPM
IPCC AR5 Synthesis Report
Mitigation Measures
More efficient use of energy
Greater use of low-carbon and no-carbon energy • Many of these technologies exist today
Improved carbon sinks • Reduced deforestation and improved forest management
and planting of new forests
• Bio-energy with carbon capture and storage
Lifestyle and behavioural changes AR5 WGIII SPM
RCPs
This assumes that there will be no major volcanic eruptions or changes in some natural sources (e.g., CH4 and N2O), or unexpected changes in total solar irradiance.
IPCC AR5 Synthesis Report
The Choices We Make Will Create Different Outcomes
With substantial
mitigation
Without additional
mitigation
Change in average surface temperature (1986–2005 to 2081–2100) AR5 WGI SPM
IPCC AR5 Synthesis Report
Stabilization of atmospheric concentrations requires moving away from the baseline – regardless of the mitigation goal.
AR5 WGIII SPM
IPCC AR5 Synthesis Report
Stabilization of atmospheric concentrations requires moving away from the baseline – regardless of the mitigation goal.
~3°C
AR5 WGIII SPM
Key characteristics of the scenarios collected and assessed for WGIII
Delaying mitigation increases the difficulty and narrows the options for limiting warming to 2°C.
„immediate action“
Delaying mitigation increases the difficulty and narrows the options for limiting warming to 2°C.
Delaying mitigation increases the difficulty and narrows the options for limiting warming to 2°C.
Delaying mitigation is estimated to increase the difficulty and narrow the options for limiting warming to 2°C.
„immediate action“
„delayed mitigation“
Delaying mitigation is estimated to increase the difficulty and narrow the options for limiting warming to 2°C.
Delaying mitigation is estimated to increase the difficulty and narrow the options for limiting warming to 2°C.
Based on Figures 6.32 and 7.16
IPCC AR5 Synthesis Report
Implications for sustainable development
➜ Climate change is a threat to equitable
and sustainable development
➜ Strategies and actions can be pursued
now that will move towards climate-resilient
pathways for sustainable development
➜ at the same time helping to improve livelihoods, social and economic well-being, and effective environmental management.
AR5 WGI SPM, AR5 WGII SPM
The window for action is rapidly closing
65% of our carbon budget compatible with a 2°C goal already used
Amount Used
1870-2011:
515 GtC
Amount
Remaining:
275 GtC
Total Carbon
Budget:
790 GtC
Fossil carbon reserves exceed this remaining budget by a factor of 4 to 7, with resources much larger still.
IPCC AR5 Synthesis Report
Synthesis is essential !
AR5 WGIII SPM
A combination of adaptation and substantial, sustained reductions in
greenhouse gas emissions can limit climate change risks
The risks from climate change, assessed by the WGII of the IPCC AR5, and aggregated in five “Reasons for Concerns”
Levels of risk across the Reasons for Concern can be associated with
a level of global temperature change.
Here shown for a warming by 2oC
The link between cumulative CO2 emissions and global mean temperature
The pink plume is from WGI complex models.
It includes the uncertainty from non-CO2 gases and climate and carbon cycle uncertainty, using the likely
range
Levels of risks can be connected to cumulative CO2 emission levels, for the average climate response, for high climate sensitivity (lower cumulative emissions), and for low climate
sensitivity (higher cumulative emissions)
Høy klima-følsomhet
Lav klima-følsomhet
The link between changes in annual GHG emissions by 2050
and the cumulative CO2 emissions by 2100 of the WGIII
scenario categories
Høy klima-følsomhet
Lav klima-følsomhet
Levels of risks can now be connected to GHG emission changes by 2050.
Added uncertainty arises from action on non-CO2 gases, timing of pre-2050 action, and ambition of
post-2050 action.
Høy klima-følsomhet
Lav klima-følsomhet
The constraint on changes in GHG emissions by 2050 depends on the sensitivity of the climate response.
Here, with large climate sensitivity
Høy klima-følsomhet
Lav klima-følsomhet
The constraint on changes in GHG emissions by 2050 depends on the sensitivity of the climate response.
Here, with low climate sensitivity
Høy klima-følsomhet
Lav klima-følsomhet
IPCC AR5 Synthesis Report
Take home messages
➜ Human influence on the climate system is clear
➜ Observed impacts are visible in all parts of the world
➜ The more we delay our responses the greater the risk
of severe, widespread and irreversible impacts; and
the greater the costs
➜ We have the options to limit climate change and build
a more prosperous, sustainable future
The report is a comprehensive map for policy makers
What does the SYR mean for the path ahead?
Policy relevant but not policy prescriptive
IPCC does not give recommendations.
But there is one thing we would like to
recommend:
Read the report!
IPCC AR5 Synthesis Report
IPCC Fifth Assessment Report
Synthesis Report