MANILA, Updated 14 March 2019 – As residents in areas of Metro Manila grapple with water scarcity issues for several days, a climate and energy policy group cautioned that climate change would only exacerbate existing risks and development issues.

Renato Redentor Constantino, executive director of the Manila-based Institute for Climate and Sustainable Cities, commented:

“As a climate policy institute, we are often the first to convey caution in prematurely attributing adverse economic, ecological or social outcomes to climate change. Many times as well, climate change merely amplifies the impacts of wrong development policies to begin with.

“Prematurely assigning blame to climate change for the current water issues of Metro Manila serves to muddle if not downplay actual projected water security risks that are several magnitudes greater than current challenges, if global temperatures continue to rise unabated. Just as important, linking climate change now dilutes critical accountability issues among government agencies and water service businesses.

“As well, go beyond Metro Manila as the public debates the scale of suffering. The country’s best scientific minds, some of whom are in PAGASA, project far greater looming human security challenges that may spark conflict in areas such as Central Mindanao, where rainfall is expected to decline dramatically exceeding the range of historical observations over the next few decades.

“Water scarcity is an annual concern especially during the summer season. We know this and the public expects the government to plan with foresight. It is thus alarming that residents in areas of Metro Manila have not had water for almost a week now.

“Government needs to also take a deeper look into how salinization, land and forest degradation, and other creeping impacts of climate change are baked into government plans and budgets. More coordination is required among government, suppliers, regulators and local government units. There is still time to address the challenges we face before a full-blown water crisis truly tests the country.”


Denise Fontanilla,


NOTE: ICSC has partnered with climate scientists from Intergovernmental Panel on Climate Change, PAGASA, the Climate Change Commission’s National Panel of Technical Experts, and state universities and colleges to study the impact of slow onset events due to climate change. Below is a synthesis of PAGASA’s second edition of “Observed and Projected Climate Change in the Philippines” which includes projections for 2050 and 2100, which was published last year.

A. Temperature

Observed temperature in the Philippines is warming at an average rate of 0.1°C/decade over the past 65 years (1951-2015). By 2050, average mean temperature could increase by as much as 0.9°C to 1.9°C for a moderate emission scenario, and by as much as 1.2°C to 2.3°C for a high emission scenario. By 2100, average mean temperature could increase by as much as 1.3°C to 2.5°C for a moderate emission scenario, and by as much as 2.5°C to 4.1°C for a high emission scenario.

B. Rainfall

Changes in rainfall have been found to vary spatially. But increasing trends in annual and seasonal rainfall have been observed in many parts of the country. These trends were found to be associated with extreme rainfall events. Projections suggest a range of +/-40% change in rainfall by the mid-21st century:

  • Wettest possible change could exceed 40% increase in rainfall, particularly over Luzon, western sections of Visayas, and some parts of Mindanao.
  • The driest possible rainfall change could reach beyond 40% reduction in many areas, particularly over Mindanao by the mid-21st century. A drier future is seen over Central Mindanao (North Cotabato, Sarangani, South Cotabato, and Sultan Kudarat), particularly during Sept-Oct-Nov and Dec-Jan-Feb seasons, which might require adaptation plans.

Province Lower bound projections Rainfall projections (2036-2065)
(% change from 1971-2000 observed trends)
Dec-Jan-Feb Sep-Oct-Nov
North Cotabato Moderate emission -13.9% decrease -28.5% decrease
High emission -15.9% decrease -18.7% decrease
Sarangani Moderate emission -24.9% decrease -31.3% decrease
High emission -9.4% decrease -26.8% decrease
South Cotabato Moderate emission -27.3% decrease -41.4% decrease
High emission -20.7% decrease -23.2% decrease
Sultan Kudarat Moderate emission -24.0% decrease -33.8% decrease
High emission -22.3% decrease -21.7% decrease

C. Tropical Cyclones

A slight decrease in the number of tropical cyclones and minimal increase in the frequency of very strong tropical cyclones have been observed over the Philippine Area of Responsibility from 1951-2015. Three of PAGASA’s five (3/5) climate model simulations suggest the frequency of tropical cyclones would decrease by the mid-21st century, four out of five (4/5) models suggest their intensity is increasing.

D. Sea Level Rise

The sea level over certain parts of the Philippines have risen by nearly double the global average sea level rise rate from 1993 to 2015. Projections reveal that sea level rise in the country is expected to increase by approximately 20 centimeters (almost 8 inches) under a high emission scenario, which might worsen storm surge hazards.