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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)
0 200 400 600 800 1,000
120
110
100
90
80
70
60
50
40
30
20
10
0
(SeaLevel)
–80 –40 0 40 80 120
Temperature (˚C)
Alt
itu
de
(kil
omet
ers)
Alt
itu
de
(mil
es)
75
65
55
45
35
25
15
5
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
2 0 N
4 0 N
- 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).
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
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 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!