PAGASA-DOST
ntroduction Observed Local Trends Temperature Rainfall Tropical Cyclones Projections for the Philippines Temperature Rainfall
Climate Change ssue ncreased use of fossil fuel Global Warming Climate Change GHG emissions Consumption of fossil fuels increases - 1.6 times over the last 4 decades Global Warming Global average temperature risen 0.74 o C during the last 100 years Changing atmospheric circulation, weather pattern Sea level rise, frequent Extreme weather Events, ncreasing Frequency and intensity of typhoons
Global mean temperatures are rising faster with time Warmest 12 years: 1998,2005,2003,2002,2004,2006, 2001,1997,1995,1999,1990,2000 Period Rate 50 0.128 0.026 100 0.074 0.018 Years /decade Source: PCC
mpacts of Climate Change (PCC AR4) TC
Observed Trends in the Philippines
OBSERVED TRENDS: Temperature Observed Temperature Anomalies in the Philippines Period: 1951-2006 (departures from the 1961-1990 normal values) ANNUAL MEAN TEMPERATURE almost 3 times increase in maximum temperatures An increase of 0.6104C from 1951-2006 MEAN ANNUAL MAXMUM TEMPERATURE MEAN ANNUAL MNMUM TEMPERATURE An increase of 0.3472C from 1951-2006 An increase of 0.8904C from 1951-2006
Majority Decreasing of trend stations show an increase in hot days and warm nights ncreasing trend Decreasing trend ncreasing trend Significant increase in the frequency of hot days Significant increase in the frequency of warm nights * Tibig, LV,et al (2004)Trends in extreme daily temperatures and 24-hr rainfall in the Phil. CABTechnical Report,PAGASA
Decreasing trend (not significant) Decreasing trend (significant) ncreasing trend (not significant) Decreasing trend (significant) Significant decrease in the number of cold days Significant decrease in the number of cool nights * Tibig, LV,et al (2004)Trends in extreme daily temperatures and 24-hr rainfall in the Phil. CABTechnical Report,PAGASA
Mean warming over the 20 th century is less than global mean land temperature change, typical of tropical regions. A pattern is apparent, with northern, southern regions warming most. Metro Manila has warmed less than most other parts of the Philippines. Warming pattern relative to 1961-1990 is somewhat weaker, but qualitatively similar.
Anomaly of Annual Philippine Rainfall With Normal Base Period 1961-1990 150 125 100 75 50 25 0-25 -50-75 -100-125 -150 Annual 5 years mean An increase of 0.6104 C from 1951-2006 (56 years)
Regions that have warmed the most (northern Luzon, Mindanao) have also dried the most. Largest precipitation trends are on the order of 10% over the 20 th century.
1128 Actual tracks With the projected increase in temperature this could mean much stronger and more intense tropical cyclones.
Frequency of tropical Cyclones Annual Number Tropical Cyclones and five-year running mean 31 26 y = -0.0104x 19.755 21 16 11 6 1 1948 1953 1958 1963 1968 1973 1978 1983 1988 1993 1998 2003 Year Number of Tropical Cyclones 5 per. Mov. Avg. (Number of Tropical Cyclones) Linear (Number of Tropical Cyclones) * Cinco,T.A.,et al.(2006). Updating Tropical Cyclone climatology in the PAR., Phil. Met-Hydro Congress 2006.
Number TRENDS N TROPCAL CYCLONE N THE PHLPPNES 250 200 150 1951-80 1961-90 1971-00 51-80 61-90 100 71-00 50 0 LUZON Luzon VSAYAS Visayas MNDANAO Mindanao
Climate Change Scenarios PRECS (25 KM) - UK MR/GCM (20 Km) - Japan
(PRECS) Projected changes in future climates in Mean Temp. For 2020 and 2050 under A1B scenario over Philippines DJF MAM JJA SON
(PRECS) Projected changes in future climates in Rainfall for 2020 and 2050 under A1B scenario over Philippines DJF MAM JJA SON
Jan-Feb-Mar (JFM) generally increase except R9,R11, decrease in mountainous rainfall over CAR April-May-Jun (AMJ) Generally decrease R3, loilo, Mindoro Occ- up to 20% major Luzon area, Visayas and Mindanao - Up to 10% But increase up to 5% in ARMM NEAR FUTURE (2015-2039) RANFALL SCENARO
July-Aug-Sep (JAS) generally increase by up to 10% Slight decrease R12 & CAR Oct-Nov-Dec (OND) greater decrease over Luzon, Visayas increase in R10 up to 20% NEAR FUTURE (2015-2039) RANFALL SCENARO
Areas statistically significant at 95% level more dry increase Eastern part wet, will be wetter JFM- An increase in rainfall (0.5-2 mm/day) decrease over the mountainous areas (W.Luzon) AMJ - Rainfall reduction in entire archipelago (5-20%); greater decrease over the mountainous areas END OF 21 ST CENTURY RANFALL SCENARO
Areas statistically significant at 95% level - significant increase along the west - coastal regions - END OF 21 ST - JFM / AMJ JAS generally increasing Greater increase R1,VB,R10 Greater increase in convective precipitation enhanced SW monsoon activity OND - Decrease about 10-20% Greater decrease over the mountainous area and coastal areas in w Luzon ncrease 10-20% in some parts of Mindanao RANFALL SCENARO
Temperature Projection 1.8-3 C increase 1.8-3 C increase ncrease in entire archipelago; Greater increase in MAM 2.1-2.7 C increase 2.1-2.7 C increase FUTURE (2075-2099)
The Philippines has warmed over the past century, but less than the global mean land surface has warmed. Northern and southern regions have dried slightly during the 20 th century, while the center, including Metro Manila, has become slightly wetter. No trend in the total number of annual country-wide tropical cyclones, but TCs in the Visayas are slightly increasing
Rainfall and Temperature projections Wet areas during NE Monsoon season (JFM) becoming wetter Wet months (JAS) becoming wetter in the future Dry months becoming Drier Warm months (MAM) becoming warmer