Fifth Assessment Report - Synthesis Report

Fifth Assessment Report - Synthesis Report

1. 1. IPCC Fifth Assessment Report IPCC AR5 Synthesis Report Synthesis Report
2. 2. The IPCC Synthesis Report ➜ Integration of three Working Group Reports of the 5th Assessment, 2013-2014 • WG I : The Physical Science Basis • WGII: Impacts, Adaptation and Vulnerability • WG III: Mitigation of Climate Change IPCC AR5 Synthesis Report
3. 3. The IPCC Synthesis Report ➜ Written by 60 authors from Working Group reports ➜ Chaired by the IPCC Chair R.K. Pachauri ➜ Member governments approved the SPM on 1st November 2014 (total membership of IPCC is 195 governments) IPCC AR5 Synthesis Report
4. 4. 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 IPCC AR5 Synthesis Report AR5 WGI SPM, AR5 WGII SPM, AR5 WGIII SPM
5. 5. Humans are changing the climate It is extremely likely that we are the dominant cause of warming since the mid-20th century IPCC AR5 Synthesis Report Year Globally averaged combined land and ocean surface temperatures AR5 WGI SPM
6. 6. Temperatures continue to rise Each of the past 3 decades has been successively warmer than the preceding decades since 1850 IPCC AR5 Synthesis Report Year Globally averaged combined land and ocean surface temperatures AR5 WGI SPM
7. 7. Oceans absorb most of the heat IPCC AR5 Synthesis Report ➜ 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
8. 8. IPCC AR5 Synthesis Report AR5 SYR SPM
9. 9. IPCC AR5 Synthesis Report AR5 SYR SPM
10. 10. IPCC AR5 Synthesis Report AR5 SYR SPM
11. 11. GHG emissions growth between 2000 and 2010 has been larger than in the previous three decades IPCC AR5 Synthesis Report AR5 WGIII SPM
12. 12. Sources of emissions Energy production remains the primary driver of GHG emissions 35% IPCC AR5 Synthesis Report 24% 21% 14% 6.4% 2010 GHG emissions Energy Sector Agriculture, forests and other land uses Industry Transport Building Sector AR5 WGIII SPM
13. 13. Antropogenic forcings are extremely likely the cause of warming IPCC AR5 Synthesis Report
14. 14. Some of the changes in extreme weather and climate events observed since about 1950 have been linked to human influence IPCC AR5 Synthesis Report AR5 WGI SPM
15. 15. Impacts are already underway • Tropics to the poles • On all continents and in the ocean • Affecting rich and poor countries IPCC AR5 Synthesis Report AR5 WGII SPM
16. 16. Projected climate changes Continued emissions of greenhouse gases will cause further warming and changes in the climate system Oceans will continue to warm during the 21st century IPCC AR5 Synthesis Report Global mean sea level will continue to rise during the 21st century Global glacier volume will further decrease It is very likely that the Arctic sea ice cover will continue to shrink and thin as global mean surface temperature rises AR5 WGI SPM
17. 17. Potential Impacts of Climate Change Food and water shortages Increased poverty IPCC AR5 Synthesis Report Increased displacement of people Coastal flooding AR5 WGII SPM
18. 18. Climate Change Poses Risk for Food Production IPCC AR5 Synthesis Report AR5 SYR SPM
19. 19. Stabilization of atmospheric concentrations requires moving away from the baseline – regardless of the mitigation goal. Based on Figure 6.7 IPCC AR5 Synthesis Report AR5 WGIII SPM
20. 20. Stabilization of atmospheric concentrations requires moving away from the baseline – regardless of the mitigation goal. IPCC AR5 Synthesis Report ~3°C Based on Figure 6.7 AR5 WGIII SPM
21. 21. Figure SPM.10, A reader’s guide From climate change risks to GHG emissions
22. 22. 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
23. 23. 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
24. 24. The link between cumulative CO2 emissions and global mean temperature The ellipses show results from the WGIII models, using a simple climate model. It does not include climate and carbon cycle uncertainty, but explores more comprehensively the scenario uncertainty from a range of CO2 and non-CO2 pathways
25. 25. 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)
26. 26. The link between changes in annual GHG emissions by 2050 and the cumulative CO2 emissions of the WGIII scenario categories
27. 27. 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.
28. 28. The constraint on changes in GHG emissions by 2050 depends on the sensitivity of the climate response. Here, with large climate sensitivity
29. 29. The constraint on changes in GHG emissions by 2050 depends on the sensitivity of the climate response. Here, with low climate sensitivity
30. 30. Limiting Temperature Increase to 2˚C Measures exist to achieve the substantial emissions reductions required to limit likely warming to 2°C (40-70% reduction in GHGs globally by 2050 and near zero GHGs 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 But delaying mitigation will substantially increase the challenges associated with limiting warming to 2°C IPCC AR5 Synthesis Report AR5 WGI SPM, AR5 WGII SPM,AR5 WGIII SPM
31. 31. 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 IPCC AR5 Synthesis Report and planting of new forests • Bio-energy with carbon capture and storage Lifestyle and behavioural changes AR5 WGIII SPM
32. 32. Ambitious Mitigation Is Affordable ➜ Economic growth reduced by ~ 0.06% (BAU growth 1.6 - 3%) ➜ This translates into delayed and not forgone growth ➜ Estimated cost does not account for the benefits of reduced climate change ➜ Unmitigated climate change would create increasing risks to economic growth IPCC AR5 Synthesis Report AR5 WGI SPM, AR5 WGII SPM
33. 33. The window for action is rapidly closing 65% of our carbon budget compatible with a 2°C goal already used IPCC AR5 Synthesis Report Amount Used 1870-2011: 1900 GtCO2 Amount Remaining: 1000 GtCO2 Total Carbon Budget: 2900 GtCO2 AR5 WGI SPM
34. 34. The Choices We Make Will Create Different Outcomes With substantial mitigation IPCC AR5 Synthesis Report Without additional mitigation Change in average surface temperature (1986–2005 to 2081–2100) AR5 WGI SPM
35. 35. IPCC Fifth Assessment Report IPCC AR5 Synthesis Report Synthesis Report