On the Science of V3
Singapore recognises the need to meet the challenges of climate change with actions based on robust science. The Centre for Climate Research Singapore (CCRS) has conducted V3 to further advance our understanding of tropical climate variability and change for Singapore and Southeast Asia for a climate-resilient society.
The models for V3 dynamical downscaling were selected based on standard criteria prescribed by the World Climate Research Programme (WCRP) Coordinated Regional Climate Downscaling (CORDEX) community. The criteria are as follows:
- Historical (present and recent past) simulations from the sub-selected GCMs should compare well with observations for multiple climate variables (such as temperature, rainfall, winds, humidity, etc.) and key climate processes relevant for climate over Singapore and SEA (such as ENSO, IOD, northeast monsoon surges, northeast monsoon, southwest monsoon, MJO, cold tongue bias, etc).
- Sub-selected GCMs should span the range of uncertainty in end-century projections of temperature and rainfall over SEA of the full ensemble of around 50 GCMs.
- Sub-selected GCMs should span the range of model genealogy. Since the GCMs are not all independent and have components in common, they can be divided into a set of family of models, and there are around 7 or so model families based on the available literature.
- Availability of 6-hourly data to force the RCM with the lateral (4 sides) and lower boundary conditions.
Similar to many parts of the world, Singapore has already been experiencing climate change as seen from local observations and satellite estimates.
Singapore's climate will continue to change due to global warming, although the amount of change will depend on the trajectory the world (including Singapore) takes. The possible future trajectories are referred to as the Shared Socioeconomic Pathways (SSPs) in IPCC AR6. Although the amount of change will depend on the SSP, overall, the key changes projected for Singapore are:
- Increase in mean sea level
- Higher temperatures
- Higher levels of Heat Stress
- More intense wet and dry extremes
- Higher wind speeds
Similar to Singapore and the rest of the world, climate change will affect the SEA region, although the magnitude of change will depend on the global warming scenario (SSPs). The key climate change projections for SEA are:
- Increased sea level rise
- Differing rainfall trends over different countries
- Higher temperatures across all SEA
- Increased wind speeds during June-July-August
Overall, compared to V2, V3 projections show elevated end-century projections for Singapore. A summary of projections for Singapore from V3 and V2 is shown in the table below:
| V3 | V2 | |
| Global Models used | CMIP6 | CMIP5 |
| Regional Model | SINGV-RCM | HadGEM3-RA |
| Future Climate Scenarios | SSP1-2.6, SSP2-4.5, SSP5-8.5 | RCP4.5, RCP8.5 |
| Spatial Resolution | 8 km and 2 km | 12 km |
| Domain Size | 8 km domain covers almost the entire Southeast Asia, and is 3 times the size of the V2 domain | Partially covers Southeast Asia |
| Bias Adjustment | Trend-preserving Quantile Mapping used in ISIMIP3 | Simple Quantile Mapping |
| Temporal Resolution of Rainfall | 12 min @ 8 km | 10 min @ 2 km |
On using V3 resources
V3 climate projections data will be available through the V3 Data Sharing and Visualisation Portal (V3-DSVP) that will be launched by early 2025. In the interim, V3 climate projections data can be obtained by Singapore Government Agencies by writing to NEA_CCRS_data@nea.gov.sg.