Climate Change Climate Change and the and the

PhilippinesPhilippines• Reviewing the Science• Detecting the Changes• Impacts on the

Philippines• Tasks to Do

Emmanuel Anglo, Ph.D.

Associate Professor Department of Environmental

Science Ateneo de Manila University

Head, Regional Climate SystemsManila Observatory

Reviewing Reviewing the the

ScienceScience

• Greenhouse warming makes earth habitable– Without CO2, Earth’s mean

temperature will be about -18°°C (no liquid water)

• Despite skeptics, unprecedented rise in CO2

emissions is causing global warming, environmental damage

GW, Clouds and Water GW, Clouds and Water VaporVapor

CO2 LEVELS RISE

TEMPERATURES RISE

EVAPORATION FROM THE OCEANS INCREASES

WATER VAPOR IN THE ATMOSPHERE INCREASES

WATER VAPOR, BEING A GREENHOUSE GAS, ABSORBS OUTGOING INFRARED RADIATION

MORE CLOUDS MEANS LESS RADIATION REACHING THE SURFACE

LESS RADIATION MEANS LESS WARMING

TEMPERATURES FALL !

Feedback processes complicate forecastsFeedback processes complicate forecasts Another major Another major positivepositive feedback: melting feedback: melting icecapsicecaps

MORE WATER VAPOR MEANS MORE CLOUDS

Red: Red: Positive Positive FeedbacFeedbac

kk

Blue: Blue: Negative Negative FeedbacFeedbac

kk

?

Climate Change Climate Change and the Philippinesand the Philippines

• Many well-known impacts of global warming (GW) not applicable to RP– Deadly heat waves are unlikely, no melting

glaciers– GW must be distinguished from local

warming (Urban Heat Island Effect)

Sea level rise: 1950 to 1990

Yanagi and Akaki 1994

Impacts of a 1-m rise in sea level

Perez et al. 1999

CRU-UEA Climate model results

• For B1 (+4% emissions, 1.5C sensitivity) to A2 (+320% emissions, 4.5C sensitivity)– SLR 7-38cm, AT 0.5-1.3 C in 2020– SLR 13-68cm, AT 0.8-2.4 C in 2050– SLR 19-104cm, AT 1.1-3.5 C in 2080

• For 2050 rain, B1 yields +6% Jun-Aug in Mindanao, A2 yields -20% Dec-Feb in Visayas and +15% Jun-Aug in Mindanao (consistent with other models)

Mactan Island, CebuCebu-Mactan

Northeast MManilaManila Bay-Laguna Lake

Bulacan-Pampanga

Climate Change Climate Change and the Philippinesand the Philippines

• Effects of GW on RP’s weather will be on

(a) Temperature, (b) rainfall and (c) tropical cyclone activity

– Which then cause impacts on other sectors: agriculture, forests, water resources, etc.

Trends in Trends in Regional Regional Surface Surface

TemperaturTemperatureses

• Nearly all non-urban stations in the region show a rise in mean temperatures between 1960 to 1998– More hot days, warm nights, fewer cold days and nights

Trends in number of hot days and warm nights (inset). Large symbols indicate where p0.05. From Manton et al. 2000.

Tropical Cyclones (TCs) and Tropical Cyclones (TCs) and Global Warming: Quick FactsGlobal Warming: Quick Facts

• Typhoons form in warm waters (>27°C)– Fewer typhoons in January to March, most frequent in

July to November– Typhoons affect Mindanao mainly in December when

sea surface temperatures (SSTs) remain warm enough– In theory, warmer SST means more frequent, stronger

storms

• Other requirements: uniform winds along vertical, enough moisture throughout troposphere– Not clear how global warming will change these

Western Pacific Typhoon Tracks (1945-2003)

100E 120E 140E 160E 180E0N

20N

40N

All YearsJuneM ax=0.76

A ll YearsM ayM ax=0.49

A ll YearsM archM ax=0.24

A ll YearsFebruaryM ax=0.27

A ll YearsAprilM ax=0.39

0N

20N

40N All YearsJanuaryM ax=0.29

0N

20N

40N All YearsDecem berM ax=0.68

0N

20N

40N All YearsNovem berM ax=1.17

100E 120E 140E 160E

All YearsSeptem berM ax=1.34

100E 120E 140E 160E

All YearsAugustM ax=1.41

100E 120E 140E 160E0N

20N

40N All YearsO ctoberM ax=1.27

100 120 140 160

All YearsJulyM ax=1.54

100E 120E 140E 160E0N

20N

40N

0 1 2 3 4 5 6 7

All YearsAnnualM ax=7.12

0 0.5 1 1.5

Legend for M onth ly Frequency:

Mean monthly and annual tropical cyclone frequency maps for the Western Pacific (1945-2003)

Geographic Trends in Tropical Geographic Trends in Tropical CyclonesCyclones

• Number of tropical cyclones appearing in the Western Pacific has been increasing

• In the Philippines, the rise in typhoon crossings is most pronounced over Visayas

100E 120E 140E 160E0N

20N

40N

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Annual increase in number of TCs. Shading indicates where p 0.01.(From Anglo 2005).

What is causing this rise?What is causing this rise?Western Pacific Sea Surface Temperatures Western Pacific Sea Surface Temperatures

(SSTs) and Annual Tropical Cyclones(SSTs) and Annual Tropical Cyclones

• Western Pacific has been warming up by 0.15°C per decade since 1976, weakly influencing tropical cyclone activity

10

15

20

25

30

35

40

45

50

1960 1965 1970 1975 1980 1985 1990 1995 2000

No

. o

f T

Cs

21.6

21.8

22.0

22.2

22.4

22.6

22.8

23.0

23.2

SS

T (

deg

C)

WPac TC SST WPac TC Trend SST Trend

Stronger Stronger Typhoons?Typhoons?

• Effect of GW on TC strength is currently the subject of intense scientific debate– Recent studies show a significant rise in number

of strong hurricanes in Atlantic, less pronounced increase in the Western Pacific

– Skeptics: Observed rise in TC strength due to (i) better observations, or (ii) natural variation

• What is certain: Philippine populations are much more vulnerable to typhoons than before– More people living in riverbanks, mountainsides– Even if TC strength doesn’t increase, numbers of

people at risk are rising

The Philippines, as The Philippines, as seen in Global seen in Global Climate Change Climate Change StudiesStudies

2007 IPCC Fourth Assessment Report: Unclear or weak trends for

the SEA region, especially RP

Jun-Jul-Aug rainfall total

Recent NASA study: Global tropical rainfall is increasing, but what about the Philippines?

Changes in Regional Changes in Regional Rainfall Extremes, 1961 to Rainfall Extremes, 1961 to

19981998 (Manton et al 2001)

Change in the frequency of days with rain

Change in the proportion of total annual rainfall contributed by heavy rain

• What this can mean: longer dry periods, but heavier rains during wet season

Changes in Mean Annual Rainfall Changes in Mean Annual Rainfall over the Philippinesover the Philippines

•Significant reduction over NE Luzon•Significant increase over Western Visayas during La Niña

•Under investigation:– Changes in the frequency of extreme rainfall events – Changes in the start of rainy season

NORMAL EL NINO LA NINA ALL YEARS

1 2 0 1 2 55

1 0

1 5

2 0

1 2 0 1 2 55

1 0

1 5

2 0

1 2 0 1 2 55

1 0

1 5

2 0

1 2 0 1 2 55

1 0

1 5

2 0

- 8 0 0 - 6 0 0 - 4 0 0 - 2 0 0 0 2 0 0 4 0 0

0 . 0 1 0 . 0 5

R a i n f a l l A n o m a l y ( m m )

S i g n i f i c a n c e ( p - v a l u e )

Difference in mean annual rainfall, 1976-2000 minus 1951-1975. ENSO events based on Multivariate ENSO Index (Wolter and Timlin 1998)

Downstream Effects of a Changing Philippine Downstream Effects of a Changing Philippine Climate Climate

Making a Bad Situation WorseMaking a Bad Situation Worse

•Energy: Bulk of local power supply in RP comes from hydroelectricity–Any decrease means more reliance on imported coal, oil

•Agriculture–Less rain or too much rain, less harvest–Changes in timing of rain also critical

–CO2 rise favors crops, but weeds like it more

–New crop varieties will be needed

Downstream Effects of a Changing Philippine Downstream Effects of a Changing Philippine Climate Climate

Making a Bad Situation WorseMaking a Bad Situation Worse •Forests and biodiversity

–Lasco (2007): Moist forests will shrink, turn to dry forests

–GW will raise flood risk, worsening degradation and species loss

•Health–Disease vectors like mosquitoes can expand range

–Water conflicts can intensify•Public welfare: More displacement

due to disasters

Marine resources: coral reef bleaching loss of fisheries

Summary of 1994 RP Summary of 1994 RP EmissionsEmissions

Summary of 1994 RP Summary of 1994 RP EmissionsEmissions

WasteWaste7%7%

AgricultureAgriculture33%33%

Industry Industry 11%11%

EnergyEnergy 49%49%

Sector

CO2 Emission

s (103 tons)

Energy 50.0Agriculture 33.1

Industry 10.6

Waste 7.1

Total 100.81990 Total (ADB 1994): 81.9 x 101990 Total (ADB 1994): 81.9 x 1033 tons tons

Where We Where We Stand Stand and and

What it What it MeansMeans

Where We Where We Stand Stand and and

What it What it MeansMeans

CO2 Emissions per Capita (tons)

•Even if the Philippines stops emitting CO2 there will be little effect on global warming

•We should reduce emissions for its other benefits: cleaner air, less oil dependence

•We should decide for ourselves

Planting Trees?Planting Trees?• How many?

– Ateneo: 14,000 students emit 3500 tons/yr: 250 kg per student

– A tropical tree removes 8 kg of CO2 per yr (or 8 tons per hectare)

– Number of trees each student needs to plant: ~ 31 trees per student

250 hectares to reforest2 times the size of the campus

• What this means: We should plant trees, but it will not be

enough

What to Do? Beg for CDM Funds

• CDM – Clean Development MechanismCDM – Clean Development Mechanism• Rich country pays industries in poor nations to Rich country pays industries in poor nations to

reduce pollution, gets the credits for reductionreduce pollution, gets the credits for reduction– Reducing COReducing CO22 emissions from poor countries has the same emissions from poor countries has the same

benefits to the donor country benefits to the donor country – Industries in rich countries already very clean and efficient, Industries in rich countries already very clean and efficient,

so a $1-M investment will reduce more COso a $1-M investment will reduce more CO22 in RP than in in RP than in the U.S. the U.S.

– Types of projects: forestry, alternative power generation, Types of projects: forestry, alternative power generation, pollution control, energy efficiencypollution control, energy efficiency

• Win-winWin-win– Rich country gets credit for CORich country gets credit for CO22 reduction as required by reduction as required by

Kyoto Protocol, poor country gets money for projectsKyoto Protocol, poor country gets money for projects

Final NotesFinal Notes• Philippine climate is changing• Impacts on many areas are currently

unclear, but may become more pronounced when warming continues

• Old lessons: Use less energy, walk, eat more veggies; reach out to the grassroots

• More science: Focus on understanding, adaptation and preparation