Projection on Increase in Surface Temperature

National Action Plan for Climate Change Adaptation RAN-API - Synthesis Report 7

2.2.2 Projection on Rainfall Changes

IPCC-AR4 models generally show changes in rainfall patterns are more varied in Indonesia, both temporally and spatially. Projection analysis based on the output of seven GCM on average showed no significant change for the period of 2020 to 2050 Bappenas, 2010c. This indicates that, up to 2020-2050 period, natural climate variability is more involved than the effects of GHGs in determining changes in rainfall. However, the changes leading up to and after 2050 needs more attention. SNC report KLH, 2010 shows the trend of fourteen GCM models to the changes in seasonal rainfall in Indonesia based on two emission scenarios SRES A2 and B1 for 2025 and 2050. The models that are part of the two scenarios agree that there is a trend towards reduced rainfall in June-July-August JJA and the transition to the September-October-November SON in Java and Nusa Tenggara Islands. In addition, the models also agree that Java and Nusa Tenggara Islands have increased rainfall in December-January-February DJF. This trend is likely to contrast with the projection for most areas in the other islands.

2.2.3 Projection on Sea Level Rise

The increase in sea level sea level riseSLR provides a huge potential threat to Indonesia which is an archipelagic country consisting many islands and small islands. In 2050, SLR due to global warming is projected to reach 35-40 cm relative to year 2000. Based on these projections, the maximum SLR including the dynamics of melting ice in Indonesia can reach up to 175 cm in 2100 Bappenas, 2010b. Estimates of the rate of increase in sea level in Indonesia based on the model that takes into account the dynamics of melting ice Bappenas, 2010b

2.2.4 Projection on Weather and Climate Extreme Events

Analysis on extreme events projection is not easy to do because it requires plenty of time for analysis and more detailed data. Therefore, it can be understood that a comprehensive study related to extreme events in Indonesia is still very limited. National Action Plan for Climate Change Adaptation RAN-API - Synthesis Report 8 Studies on changes in the odds of extreme events in the Indonesian territory are more focused on extreme rainfall events. As for the extreme events related to the temperature change such as heat waves, do not show a significant trend at least up to 2050, either according to the study of historical data such as that written by Manton et al, 2001, as well as GCM studies.

2.3 Potential Impacts of Climate Change

Theoretically, the change in climate indicators such as surface temperature, precipitation, sea surface temperature, sea level, extreme climate events ENSO, IOD, DMI, IPO, and extreme weather events heavy rain, strong storm winds, and storm surge which have been projected above will give rise to a variety of potential impacts on areas related to national development system whether in terms of economic , livelihood, ecosystem, as well as special regions. Climate change impacts in Indonesia have been studies quite a lot eventhough the scope of the studies are generally still in national scale. The two main references which can be used are the Indonesia Climate Change Sectoral Roadmap ICCSR developed by Bappenas and Second National Communication SNC developed by KLH, both in 2010. In ICCSR, it was mentioned that the potential impacts of climate hazards can affect the key sectors such as water, marine and fisheries, health, agriculture, and forestry. In the water sector, climate change may lead to the four major hazard, i.e., decrease in water availability, floods, landslides, and droughts which are generally caused by the parameters of rainfall and extreme weather and climate events. ICCSR and SNC documents have identified the distribution of major climate change hazard risks level in Indonesia. Java, Bali and Sumatra islands are mentioned as three areas that have high and very high risk compared to other regions.The risk is associated with a high degree of vulnerability caused by population, residential areas, and infrastructure in the three regions. The level of climate change risks in Indonesia by region modified from the data of ICCSR and SNC documents Risks Sumatra Java-Bali Kalimantan Sulawesi Nusa Tenggara Maluku Papua Decrease in water availability M, H, VH H, VH L, M H, VH H, VH L, M L Flood H, VH H, VH L, M, H L, M, H L L L, M Drought H, VH H, VH L L, M L, M, VH L L Coastal inundation M, H M, H, VH M, H, VH M, H M, H M, H M, H The spread of dengue fever L, M, H L, M, H L, M L, M L, M L, M L, M, H The spread of Malaria L, M L, M, H L, M L, M, H L, M, H, VH M, H M, H, VH The spread of Diarrhea L, M, H L, M, H L, M, H L, M, H L, M, H L, M, H L, M, H, VH Decrease in rice production H, VH H, VH - - H, VH - - Forest fires M, H, VH M, H - - - - - Note: L: Low; M: Moderate; H: High; VH: Very High