National Seminar on Socio-Economic Impact of Extreme Weather and Climate Change

1. Climate Change and Extreme Weather: IPCC Findingsby:Yap Kok SengMalaysian Meteorological DepartmentMinistry of Science, Technology and Innovation National Seminar on Socio-Economic Impact of Extreme Weather and Climate Change 21-22 June 2007, Putrajaya Marriott Hotel

2. Introduction:- trends in climate variables - sea level - extreme weather Future Climate: - climate scenarios - climate projections Climate Variability: - El Nino Concluding Remarks SCOPE

4. Annual Temperature Trend for 1901 to 2005 (above) and 1979 to 2005 (below) Peninsular Malaysia ~ 0.5oC per Century Malaysia ~ 0.1oC per Decade Source: IPCC, 2007

6. Annual Rainfall Trend for 1901-2005 (above) and 1979-2005 (below) Peninsular Malaysia ~ 3% per Decade Source: IPCC, 2007 Drier Wetter

8. Changes in Temperature, Sea Level and Northern Hemisphere Snow Cover Relative to 1961–1990 Averages Increase in global average temperature, 100-year linear trend (1906 – 2005): 0.74oC [0.56 to 0.92] Rate of global average sea level rise, Over 1961 – 2003:1.8 mm per year [1.3 to 2.3] Over 1993 – 2003: 3.1 mm per year [2.4 to 3.8] Source: IPCC, 2007

9. SEA LEVEL HAS RISEN BY 0.2-0.3 METERS IN LAST CENTURY

10. Have tropical cyclones become more extreme?

11. Number of intense hurricanes has increased 100 Cat. 1 80 Cat. 2+3 60 Cat. 4+5 Webster, Holland, Curry and Chang (2005)

12. How about smaller scale severe weather systems such as thunderstorms and tornadoes? Water Sprout at Kudat, 2006

13. Recent Trends of Extreme Weather Events and Assessment of Human Influence on the Trend (IPCC, 2007) Virtually certain: > 99% probability of occurrence Extremely likely: > 95% Very likely: > 90% Likely: > 66% More likely than not: > 50% Unlikely: < 33% Very unlikely: < 10% Extremely unlikely: < 5%

14. Future Climate: - climate scenarios - climate projections

15. Multi-model means of surface warming relative to 1980-1999 for the scenarios A2, A1B and B1. Numbers indicate the number of models which have been run for a given scenario. The gray bars at right indicate the best estimate (solid line within each bar) and the likely range assessed for the SRES marker scenarios. (IPCC, 2007)

16. Projected global average temperature changes for the early and late 21st century relative to the period 1980 – 1999, as calculated by multi-model averages for a low (B1), a medium (A1B) and a high SRES scenario for the decades 2020-2039 (left) and 2090-2099 (right). (IPCC, 2007)

17. Projected global average precipitation changes for the late 21st century (2090-2099) relative to the period 1980–1999. The estimates are based on multi-model average projections for the medium (A1B) scenario for December to February (left) and June to August (right). White areas are where less than 66% of the models agree in the sign of the change and stippled areas are where more than 90% of the models agree in the sign of the change. (IPCC, 2007)

18. SEA LEVEL RSIES AT END OF 21ST CENTURY Smaller range in sea level rise compared to TAR because of improved information on uncertainties in the projected contributions c pared to TAR

20. Projections for Extreme Weather Events (IPCC, 2007)

21. Future climate over Pacific (El Nino/La Nina) : • Weak shift towards towards average background conditions which may be • described as “El Nino” like • Eastward shift in mean precipitation • Weakened tropical Circulation • Continued inter-annual variability of ENSO • No consistent indication of discernable changes in amplitude or frequency • of ENSO

22. NORTH ATLANTIC THERMOHALINE CIRCULATION – approx 25% reduction by end of 21st century

23. pH reduction between 0.14 to 0.35 units in the 21st century adding to the present decrease of 0.1 units From pre-industrial times

24. Abnormal weather in 2005 & 2006 – Is it due to Climate Change or Climate Variability? 2006 Thunderstorm and Strong Winds at Subang Jaya, 9 Mac 2006 Lightening caused fire at Pasir Gudang Port, Johore on 18 April 2006 Haze in Kuala Lumpur on 3 October 2006 Flood in Kota Tinggi, Johore on 29 December 2006.

25. Abnormal Northeast Monsoon 2006/2007 Warmer winter & late onset Late ending of tropical storm season El-Nino -Warmer sea surface temperature Late onset of northeast monsoon Warmer sea surface temperature Late onset of Australia/Indonesia monsoon These conditions had caused complex interaction within the atmosphere and ocean circulation system Is it due to Climate Change or Climate Variability?

26. Concluding Remarks The climate will be warmer in future independent of the scenario assumed. However, the degree of this warming, particularly during the latter half of the century, is determined by the strength of the scenario pathway followed. IPCC scientists have interpreted the increase in climate variability and extreme weather events as signals of the impacts of climate change due to global warming. Whether these increases are due to global warming as a result of anthropogenic activities of mankind, or due to long term natural variability of the climate itself, it is clear we need to take further steps to better prepare ourselves against the impacts of such changes.

27. Thank You