Climate Change Climate Change and the and the

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

Philippines• Responses

Department of Environmental

Science Ateneo de Manila University

Head, Regional Climate SystemsManila Observatory

Pressure = 1,000millibars atground level

Atmospheric pressure (millibars)

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(SeaLevel)

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Temperature (˚C)

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Thermosphere

Heating via ozone

Mesosphere

Stratosphere

Ozone “layer”

Troposphere

Temperature

Pressure

Mesopause

Stratopause

TropopauseWe are fish swimming under a sea

of air!

Types of Air PollutantsTypes of Air Pollutants

Primary Primary PollutantsPollutants

Secondary Secondary PollutantsPollutants

CO CO2

SO2 NO NO2

Most hydrocarbons

Most suspendedparticles

SO3

HNO3 H2SO4

H2O2 O3 PANs

Most and saltsNO3– SO4

2 –

Solarradiation

Energy inEnergy in = = Energy outEnergy outReflected byatmosphere (34%)

UV radiation

Absorbedby ozone

Absorbedby the earth

Visiblelight

Lower Stratosphere(ozone layer)

Troposphere

Heat

Greenhouseeffect

Radiated byatmosphere

as heat (66%)

Earth

Heat radiatedby the earth

Greenhouse EffectGreenhouse Effect

Rays of sunlight pwarm the earth's surface.

Earth's surface absorbs muchcoming degrades it to longer-wavelength infrared radiation (heat), which rises iabsorbed by molecules of greenhouse gases awarms the lower atmosphere.

As concentrations of greenhouse gases rise, more heat to the lower atmosphere.

(a)(a) (b)(b) (c)(c)

Reviewing Reviewing the the

ScienceScience

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

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

• Unprecedented rise in CO2

concentrations is causing global warming, environmental damage

Inconvenient Inconvenient TruthsTruths• It’s our fault

– Impact of human CO2 emissions now exceed natural influences

• It will warm up– Forecasting tools

work, and they predict a warmer planet

What about the What about the Philippines?Philippines?

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

melting glaciers around– Tropical, marine conditions tend to

keep weather and climate stable– GW must be distinguished from

local warming (Urban Heat Island Effect)

Is it just the Urban Heat Island Effect ?Is it just the Urban Heat Island Effect ?

• UHI – Warming of urban areas due to removal of trees UHI – Warming of urban areas due to removal of trees and water bodies, and replacement with concrete and water bodies, and replacement with concrete and metaland metal

• Many weather stations record a steady warming due Many weather stations record a steady warming due to UHI, not GWto UHI, not GW

Stations far away from cities still record a steady warming, though not as large as those in urban areas

Other indicators are also consistent with GW

Climate Change Climate Change and the Philippinesand the Philippines

• Likely Effects of Global Warming on the Philippines: – Sea level rise– (a) Temperature, (b) rainfall and (c) tropical

cyclone activity . . .– . . . Which then cause impacts on other

sectors: agriculture, forests, water resources

Sea Level Rise in the Philippines

Yanagi and Akaki 1994Hulme and Sheard 1999

Perez et al. 1999

Manila Bay (Blue)Legaspi (Red)

Mactan Island, Cebu

Northeast MManila

Bulacan-Pampanga

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

• Not enough to cause heat waves, but may affect agriculture

– IRRI (2004): Rice yields decline with higher nighttime temperatures

Trends in number of hot days and warm nights (inset). Large symbols indicate where p� 0.05. 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

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

1 0 0 E 1 2 0 E 1 4 0 E 1 6 0 E0 N

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

Stronger Stronger Typhoons?Typhoons?

• Effect of GW on TC strength is currently the subject of intense scientific debate– Other TC requirements: uniform winds along

vertical, enough moisture throughout troposphere

– Not clear how global warming will change these

• 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

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: Change 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

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1 5

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- 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 in rainfall means more reliance on imported coal and oil

•Agriculture–Less rain or too much rain means less harvest

–Changes in timing of rain also critical

–CO2 rise favors crops, but weeds like it more

–CO2 rise can enhance corn growth, but only in roots and stalk, not its edible parts

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

–Moist forests will shrink, turn into dry forests

–GW may raise flood risk, worsening habitat degradation and species loss

–However, human impact still much more damaging

•Health–Disease vectors (i.e. mosquitoes) will expand range

–Displacement due to disasters will be a worsening health issue

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

Making a Bad Situation WorseMaking a Bad Situation Worse •Water Resources

–Rainfall is decreasing over Luzon and parts of Mindanao where major dams are found

–Rainfall is increasing in the Visayas where there are no major dams

–Sea level rise may cause salinity intrusion; Laguna Lake at risk

•Marine Resources–Warmer temperatures can kill coral (as in 1998)

–Higher CO2 in atmosphere can disrupt carbonate chemistry, make shell and bone formation difficult

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 100.8

1990 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

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

Actions Needed Actions Needed • Reduce exposure and vulnerability

– Evacuate risky areas; enhance preparedness

• Build new dams• Develop, promote new crops and

farming tech• Seek co-benefits, not just mitigate

– Save energy, promote clean mass transport to improve air quality

– Promote renewables to reduce oil dependence

• Reduce pressure on resources by finding alternative livelihoods

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

• A tropical tree removes 8 kg of CO2 per yr (or 8 tons per hectare)– Old trees don’t count; trees must reach maturity– Trees may be cut, but should NOT be burned nor

allowed to rot• Number of trees each student needs to plant:

~ 31 trees per student250 hectares to reforest

2 times the size of the campus• To sequester current emissions: each Pinoy should

plant at least 100 trees per year• What this means:

Planting trees enhance surroundings and habitats, but it will never be enough against

climate change

Plant How Many Trees?Plant How Many Trees?

A Better Response:

EAT LESS MEAT

• Heller and Keolian (2000): Impact of meat eating is nearly the same as driving a car

• Philippine 1990 livestock production emitted 10,000 tons of CO2 equivalent– Equal to our industrial emissions, or

10 percent of our total

• Ecology 101: feeding a vegetarian uses 90 percent less land than a meat eater

Final NotesFinal Notes• Impacts on many sectors are currently

unclear, but may become more pronounced as warming continues

• Science needed: Focus on understanding, adaptation and preparation

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

• Filipinos should reduce their greenhouse gas emissions, but for the right reasons

Thank You!