MEDIA RELEASE – IPCC’S Latest Future Increases in Global Sea-Level Rise and More Extreme Rainfall in the Region
- Climate science findings released in Stockholm on 27 September by the Inter-governmental Panel on Climate Change (IPCC) suggest significant changes in rainfall patterns and increased global sea-level rise by 2100.
- The findings were released as part of IPCC’s 5th Assessment Report (AR5) ‘Summary for Policymakers’ (SPM) by Working Group I (WGI): The Physical Science Basis (refer to Annex A for details). The SPM contains updated interpretations of past climate as well as projections of the future.
- The findings of AR5 are consistent with those of the 4th Assessment Report (AR4), and show that the climate is undergoing significant change. The Singapore Government will contextualise the global findings from AR5 and study their impact on Singapore and its people. As new knowledge and information on the effects of climate change become available, continual efforts are being made to review and adjust plans.
- For future rainfall, the SPM shows that trends vary widely across different regions of the world. Nonetheless, the SPM notes that in a warmer world, extreme rainfall events over wet tropical regions will very likely become more intense and more frequent. The view from the scientific community is that detailed prediction of rainfall in the tropics is a major challenge due to the complexity of the physical processes involved, and remains an area of active research.
- The SPM, in its analysis of past rainfall, shows that more regions of the world experienced an increase in the number of intense events. However, a number of regions experienced decreases, and there was no uniform pattern world-wide.
- In Singapore, analysis by the Centre for Climate Research Singapore (CCRS) indicates that there has been more frequent and intense short duration heavy rainfall over the past few decades. Over this period, the number of days each year with heavy rainfall of more than 70 mm in an hour increased as a regular trend from five days in 1980 to ten days in 2012. The annual maximum rainfall intensity in an hour also increased from 80 mm in 1980 to 107 mm in 2012. There was no significant trend for prolonged dry spells over this period.
- Scientifically, it is not possible with current models to pinpoint the cause of past rainfall changes in Singapore, as a combination of factors such as global warming, natural climate variability and other effects could have played a part. However, research is ongoing and advances could be made in the future.
- Using global sea level over the period of 1986-2005 as the reference point, the SPM’s current analysis is that there could be a rise of 0.26m-0.82m by the period of 2081-2100, depending on the level of greenhouse gas emissions. The most aggressive climate change scenario1 could see a total rise of 0.52m-0.98m by the year 2100. Location-specific coastal effects, which could be due to ice sheet/glacial processes, tectonic processes, coastal processes, and local human activities will add to this change in mean global sea level.
- Looking further ahead, the SPM mentions that the Greenland Ice Sheet could take over a millennium or longer to melt completely. If this were to happen, mean global sea level would rise by up to 7m compared to present day. However the uncertainty is large in projecting the climate over such a long time-scale, and further research is required to refine the estimates.
- For the period of 2081-2100, the SPM projects that average surface temperatures across the world will increase by at least 0.3°C-1.7°C under the least severe climate change scenario2, and by 2.6°C-4.8°C for the most aggressive climate change scenario.
- The findings of the SPM imply that the temperatures that Singapore encounter occasionally could become the norm in the future. More aggressive climate change may affect how Singaporeans carry out their day-to-day activities and the way that future infrastructure is planned.
Staying Resilient In The Face Of Climate Change
- The effects of climate change operate in the long term, but the Government is taking a proactive approach to address its potential impact. The Inter-Ministerial Committee on Climate Change (IMCCC) was established in 2007 to enhance Whole-of-Government coordination on climate change policies. The Resilience Working Group (RWG), an inter-agency platform under the IMCCC, studies Singapore’s vulnerability to the effects of climate change and recommends long-term plans that ensure the nation’s adaptation to future environmental changes.
- Through Singapore’s 1st National Climate Change Study (2007-2013), which made use of data and scenarios from IPCC AR4, a preliminary understanding was gained of how climate change could affect Singapore. The Study was conducted by the National Environment Agency (NEA), under the auspices of RWG. Phase 1 of the Study was completed in 2009 and Phase 2 concluded this year. Phase 2 looked into the potential impacts of climate change on biodiversity, public health, the urban temperature profile, and energy consumption of buildings. The relevant agencies have taken these findings into account in their resilience plans, such as in enhancing the stability and connectivity of our existing green areas, reviewing our monitoring and maintenance regimes, as well as putting in place plans to better understand the effects of urbanisation together with climate change.
- With the release of IPCC AR5, it is necessary to leverage the global and regional-level findings and investigate them at country/ city level, so that we can update our knowledge and resilience plans. This will be carried out in Singapore’s 2nd National Climate Change Study. Work is now ongoing at CCRS, in collaboration with the UK Met Office, to project climate parameters in greater detail to help the Government better understand the local impacts of climate change. The results will eventually strengthen Singapore’s climate resilience and adaptation plans.
For useful Questions and Answers on findings from the IPCC AR5, click here
The Intergovernmental Panel on Climate Change (IPCC)
The Intergovernmental Panel on Climate Change (IPCC) is the international body for assessing the science related to climate change. The IPCC was set up in 1988 by the World Meteorological Organization (WMO) and United Nations Environment Programme (UNEP) to provide policymakers with regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation.
IPCC assessments are policy-relevant but not policy-prescriptive. They present projections of future climate change based on different scenarios, outline the risks that climate change poses, and discuss the implications of response options, but they do not tell policymakers what actions to take.
The IPCC provides rigorous and balanced scientific information to decision-makers because of its scientific and intergovernmental nature. Participation in the IPCC is open to all member countries of the WMO and United Nations. It currently has 195 members. The Panel, made up of representatives of the member states, meets in Plenary Sessions to take major decisions. The IPCC Bureau, elected by member governments, provides guidance to the Panel on the scientific and technical aspects of the Panel’s work and advises the Panel on related management and strategic issues.
IPCC Assessment Reports
The IPCC assessment reports are written by leading scientists who volunteer their time and expertise as Coordinating Lead Authors and Lead Authors of the reports. They enlist hundreds of other experts as Contributing Authors to provide complementary expertise in specific areas. Assessment reports undergo multiple rounds of drafting and review to ensure they are comprehensive and objective, and are produced in an open and transparent way. Thousands of other experts contribute to the reports by acting as reviewers, ensuring the reports reflect the full range of views in the scientific community. Teams of Review Editors provide a thorough monitoring mechanism for making sure that review comments are addressed.
The IPCC works by assessing published literature. It does not conduct its own scientific research. The authors provide information on areas where knowledge is well-established and where understanding is evolving, as well as where multiple perspectives exist in the literature.
The IPCC’s First Assessment Report (FAR) in 1990 played a decisive role in leading to the United Nations Framework Convention on Climate Change (UNFCCC), which was opened for signature at the Rio de Janeiro Summit in 1992. The Second Assessment Report (SAR) of 1995 provided key input for the negotiations of the Kyoto Protocol in 1997. The Third Assessment Report (TAR) of 2001 provided further information relevant to the development of the UNFCCC and the Kyoto Protocol. The 4th Assessment Report (AR4) paid greater attention to the integration of climate change with sustainable development policies and the relationships between mitigation and adaptation, and led to a wider awareness of climate change issues in the general public and among decision-makers. In 2007, after the release of AR4, the Nobel Peace Prize was awarded to the IPCC3 for its efforts in disseminating knowledge and laying the foundations for action on climate change.
The 5th Assessment Report (AR5), which will be finalised in 2014, places greater emphasis on assessing the socio-economic aspects of climate change and its implications for sustainable development. It also includes a number of new features such as a new set of climate scenarios, dedicated chapters on sea level change, the carbon cycle and climate phenomena, greater regional detail and information on risk management.
Working Groups under the IPCC
The authors that produce the assessment reports are mainly organised into three working groups – Working Group I: the Physical Science Basis; Working Group II: Impacts, Adaptation and Vulnerability; and Working Group III: Mitigation of Climate Change.
Each of the working groups generates a report and a Summary for Policymakers (SPM). AR5 comprises the three reports of the working groups and a fourth section known as the Synthesis Report.
The Working Group I contribution to AR5 includes assessing observations of the climate system, across the atmosphere, the surface, the ocean and the cryosphere (ice), as well as information on past climate.
1 “Representative Concentration Pathway” (RCP) 8.5. In AR5, a selection of four greenhouse gas concentration pathways were used as the input to drive climate models: RCPs 2.6, 4.5, 6.0 and 8.5. The higher numbers represent greater projected imbalances in the climate by the year 2100.
2 “Representative Concentration Pathway” (RCP) 2.6. See footnote 1.
3 As co-recipient with Albert Arnold “Al” Gore, Jr, former US Vice-President and environmental activist.