Climate Change And The Philippines

Climate Change and the Philippines
Reviewing the Science
Detecting the Changes
Impacts on the Philippines
Responses
Department of Environmental Science Ateneo de Manila University Head, Regional Climate Systems Manila Observatory

We are fish swimming under a sea of air! Pressure = 1,000 millibars at ground level Atmospheric pressure (millibars) 0 200 400 600 800 1,000 120 110 100 90 80 70 60 50 40 30 20 10 0 (Sea Level) – 80 – 40 0 40 80 120 Temperature (˚C) Altitude (kilometers) Altitude (miles) 75 65 55 45 35 25 15 5 Thermosphere Heating via ozone Mesosphere Stratosphere Ozone “layer” Troposphere Temperature Pressure Mesopause Stratopause Tropopause

Types of Air Pollutants Primary Pollutants Secondary Pollutants CO CO 2 SO 2 NO NO 2 Most hydrocarbons Most suspended particles SO 3 HNO 3 H 2 SO 4 H 2 O 2 O 3 PANs Most and salts NO 3 – SO 4 2 –

Solar radiation Energy in = Energy out Reflected by atmosphere (34%) UV radiation Absorbed by ozone Absorbed by the earth Visible light Lower Stratosphere (ozone layer) Troposphere Heat Greenhouse effect Radiated by atmosphere as heat (66%) Earth Heat radiated by the earth

Greenhouse Effect Rays of sunlight p warm the earth's surface . Earth's surface absorbs muchcoming degrades it to longer-wavelength infrared radiation (heat) , which rises i absorbed by molecules of greenhouse gases a warms the lower atmosphere. As concentrations of greenhouse gases rise , more heat to the lower atmosphere. (a) (b) (c)

Reviewing the Science
Greenhouse warming makes earth habitable
Without CO 2 , Earth’s mean temperature will be about -18 ° C (no liquid water)
Unprecedented rise in CO 2 concentrations is causing global warming, environmental damage

Inconvenient Truths
It’s our fault
Impact of human CO 2 emissions now exceed natural influences
It will warm up
Forecasting tools work, and they predict a warmer planet

What about the 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 ?
UHI – Warming of urban areas due to removal of trees and water bodies, and replacement with concrete and metal
Many weather stations record a steady warming due to 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 and 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 1994 Hulme and Sheard 1999 Perez et al. 1999 Manila Bay (Blue) Legaspi (Red)

Mactan Island, Cebu

Northeast MManila

Bulacan-Pampanga

Trends in Regional Surface Temperatures
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 Global 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 Cyclones
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
Annual increase in number of TCs. Shading indicates where p  0.01. (From Anglo 2005).

Stronger 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 Rainfall Extremes, 1961 to 1998 (Manton et al 2001)
What this can mean: longer dry periods, but heavier rains during wet season
Change in the frequency of days with rain Change in the proportion of total annual rainfall contributed by heavy rain

Changes in Mean Annual Rainfall over the Philippines
Significant reduction over NE Luzon
Significant increase over Western Visayas during La Ni ñ a
Under investigation: Change in the start of rainy season
Difference in mean annual rainfall, 1976-2000 minus 1951-1975. ENSO events based on Multivariate ENSO Index (Wolter and Timlin 1998) NORMAL EL NINO LA NINA ALL YEARS

Downstream Effects of a Changing Philippine Climate Making 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
CO 2 rise favors crops, but weeds like it more
CO 2 rise can enhance corn growth, but only in roots and stalk, not its edible parts

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

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 CO 2 in atmosphere can disrupt carbonate chemistry, make shell and bone formation difficult

Summary of 1994 RP Emissions 1990 Total (ADB 1994): 81.9 x 10 3 tons Waste 7% Agriculture 33% Industry 11% Energy 49% Sector CO 2 Emissions (10 3 tons) Energy 50.0 Agriculture 33.1 Industry 10.6 Waste 7.1 Total 100.8

Where We Stand and What it Means CO 2 Emissions per Capita (tons)
Even if the Philippines stops emitting CO 2 there will be little effect on global warming
We should reduce emissions for its other benefits : cleaner air, less oil dependence

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 CO 2 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 student
250 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?

A Better Response:
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 CO 2 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
EAT LESS MEAT

Final 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!

Climate Change And The Philippines

by meih on Apr 20, 2009

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Climate Change And The Philippines — Presentation Transcript