Session 1.1.3. Climate Projections
- 1. Climate Change Projections: Contribution to adaptation pathways Dr Bertrand Timbal Centre for Climate Research Singapore Meteorological Service Singapore ASEAN Specialized Meteorological Centre
- 2. Physical Science Basis Mitigation Impacts, Vulnerability, Adaptation Climate Science: The IPCC • 5th AR (2013-2014) • 6th AR (2021-2022) What is the IPCC? • International body to assess the science: scientists volunteer time and expertise • ARs provide the scientific basis for governments at all levels to develop climate related policies Policy Relevant not policy prescriptive
- 3. Climate Change information and data • Global Climate database: Coupled Model Intercomparison Project: CMIP (currently 6) Understand the response of the global climate system • Regional Climate Models: CORDEX (WMO sponsored program as part of WCRP) Accessing VIAs compatible regional data (high resolution: 10-40km) • National projections: National Meteorological & Hydrological Services (NMHSs) Information tailored to National Adaptation Planning International effort to coordinate and stream line delivery of climate information Global Framework for Climate Services (GFCS) supported by WMO
- 4. Full CMIP5 archive from the international community (4 RCPs & 40+ GCMs) “Illustrative” scenarios selected (RCP 4.5 & 8.5) 9 GCMs selected: “suitable” for Singapore climate RCM Downscaling: century-long simulations 12km resolution Convection Permitting RCM 10 years “time-slices” Bias corrected local projections •Anthropogenic forcing: Plausible future paths of socio-economic development •Global Climate System: Different modelled responses to the anthropogenic forcing •Downscaling linkage: Response of the regional climate to global climate change(s) •Convective Process resolved: Response of localized weather systems to regional climate change •Local Information: Statistical adjustments to provide local information for quantities of relevance to users Numerical Modelling Tools Uncertainties Considered The cascade of uncertainties
- 5. An holistic approach to adaptation Courtesy of Singapore Water management agency Changes in • Rainfall • Sea Level • Temperature Changes in: • Mean • Variability • Extreme frequency • New extremes Science based!
- 6. Adapt to Climate Change or Variability? Climate Variability: natural variations in the average climate on different time scales (some understood) Climate Change: more ‘persistent’ variation over a long period of time indicate a change in the climate: mean, variability or extremes 1500 2000 2500 3000 3500 4000 1860 1880 1900 1920 1940 1960 1980 2000 2020 MacRitchie (Singapore) annual rainfall Is this Climate Change ? Or is this Climate Variability ? Climate Change vs. Climate Variability is a timescale issue Annualrainfall(mm)
- 7. Adaptation: variability (now) & change (future) Singapore’s Temperature Dashboard Emission scenarios: • Mid-term (2030-2050): no real impact • Critical by end of century: decision is now! Monitoring tool: • Climate is changing • Variability & change • Envelop of risk is evolving
- 8. Adapting to uncertain future(s) Differing extent of change for different climate scenario: Climate Change Projections Range of results for different climate models • All models provide plausible climate futures • Median model does not equate to the most likely change • Not feasible to plan for worst case in every aspect affected by climate change • Not advisable to treat extremes as outliers and remove them when planning for climate change Source: 2nd National Climate Change Projections for Singapore, 2015 Stakeholder Report
- 9. Source: Mekong River Commission (MRC), 2017: Technical Report of Climate change impacts on hydrology of the Lower Mekong Basin Chiang Sean Vientiane Adapting to uncertain future(s)
- 10. Lessons learnt from ASEAN community • Need for a centralised approach – Coordinate studies on projections and data consolidation activities – Provide guidance on: generation and usage of climate models • Region-specific guidance document – Standardisation of technique for intercomparability synthesise different studies – Provide regional perspective on robust scientific understanding optimisation • Early user engagement communicate uncertainties & packaging of information • Probabilistic projections still not common translation to risk • Not all NMHSs are tasked to generate climate projections •Regional workshops on: •Best practices •Climate extremes Discuss •Science: CORDEX-SEA •Applications to sector specific users Design •South-East Asia RCC-Network •Delivery of Climate Services Deliver
- 11. • One-stop portal for accessing, analyzing and visualizing GCM outputs CDAAS – Climate Data Access and Analysis System Regional data portals (I)
- 12. Pacific Climate Change Data Portal For the upload, analysis and visualisation of homogenised climate data in the Pacific Approx. 100 station records for 23 countries and territories (excluding the Aust. and NZ mainland) Data can be updated/modified by participating national meteorological services Regional data portals (II)