Asia’s Sinking Cities: Philippines

Being an archipelagic country, the Philippines is experiencing sea level rise (SLR) three to four times faster than the global average rate (DFA). The graph shows up to 9 million people in the Philippines living on land are expected to be under sea level by 2100.

Fig. 1. Philippines is tagged red in the global estimate of people living on land expected to be under sea level by 2100 (adapted from Statista graph https://www.statista.com/chart/19884/number-of-people-affected-by-rising-sea-levels-per-country/)

Below are projections on sea level rise (SLR) and its implication to coastal municipalities until the end of the century:

  1. Sea level in the country will continue to be slightly larger than the global average. Certain parts of the country have risen sea level by 5.7– 7.0 millimeters per year from 1993-2015. This is approximately double the highest global average rate of 2.8–3.6 millimeters per year. Increased frequency and severity of storm surge, floods, landslides, and droughts are expected to exacerbate risks to agriculture, energy, water, infrastructure, human health, and coastal ecosystem – Climate Change Commission
  2. Projected SLR is 23–47 cm by the end of the century (2090-2099). Actual SLR vary around the country due to differences in ocean circulation and density – USAID
  3. Four Philippine cities (San Jose, Manila, Roxas, Cotabato) rank among the top 10 East Asian cities likely to be affected by SLR and storm surges. Some studies project that storm surge zones may increase by over 25% relative to present levels – 2011 Global Facility for Disaster Reduction and Recovery and World Bank
  4. Forest mangroves in the pacific islands are predicted to have 13% decrease using upper projection of global SLR by 2100 (10-15% mangrove is lost globally). Mangrove forests protect coastal communities from storm surges and prevent soil erosion and coastal sedimentation that leads to low photosynthesis, vulnerability to bleaching events, and mortality in corals and seagrass. Increase in soil erosion and sedimentation creates cascading hazards and disaster in the fisheries and decreased biodiversity and biomass (or marine resources).
  5. Increase in sequestered carbon due to declining mangrove forests in coastal areas perpetuates an increase in temperature that will also result in SLR (OML).

Sinking Cities

Among the most vulnerable cities that are projected to be inundated due to rising sea level is the City of Manila. According to Greenpeace East Asia, it will be submerged in seawater and coastal flood by 2030 should extreme sea level rise and subsequent storm surge occur. Its highly populated residential, industrial, and commercial areas are projected to have a GDP loss of US$39 billion. Manila Bay seawater is rising 13.24 millimeters per year. Metro Manila is sinking by 10 centimeters annually due to rapid urbanization and extraction of groundwater.

Fisher communities and low-lying islands are at high risk to SLR. About 64 million people living along the coast will be directly exposed to SLR are threatened with loss of homes, livelihood, and even lives. Dr. Laura David from the University of the Philippines Marine Science Institute discussed the current and future risks and impacts of sea level changes to communities/municipalities relying on coastal resources (such as coral, mangrove, and seagrass). In a forum, she identified the municipalities that will likely be exposed to extreme effects of rising sea level: Sulu and Tawi-tawi, Cotabato City, Pangasinan, Isabela, Bulacan (3), Batangas, Quezon,Cavite, Palawan, Masbate and Camarines Sur, Negros Occidental, Iloilo, Bohol, Cebu Eastern Samar, Zamboanga del Norte and Zamaboanga del Sur. 

Adapting to threat

According to climate.gov, despite the efforts to curb GHG emissions, global sea level would rise at least 8 inches (0.2 meters) above 1992 levels by 2100. However, it is important to note that higher GHG rates would trigger higher chances of SLR. 

Fig . 3. Possible future sea levels for different GHG pathways (adapted from Climate.gov).

Poor urban planning, poverty coupled with a degraded environment will worsen the effects of SLR. In the Philippines and most Southeast Asian countries, traditional disaster risk reduction measures aren’t holistic and sufficient to deal with our warming planet, according to Ven Paolo Valenzuela (Inquirer.net). 

“Philippines needs an extensive and careful assessment of observed local sea level rise. The country should identify what are adversely affected by SLR (vulnerability assessment) and incorporate them in the Comprehensive Land Use Plan (CLUP) of the local government units. The findings of the vulnerability assessment must then be the basis of the local climate change action plan. Actions to address sea level rise should include adaptation of buildings and human settlements, including farms, protection and/or defence by building dikes or flood barriers, retreat by either relocation and/or abandoning settlements that are threatened. The country should mainstream these observations in the national and local development planning, in particular in terms of local climate change action,” says Dr. Lourdes Tibig, meteorologist and climatologist.

Greenpeace believes that the government efforts to avoid SLR such as the NDC is insufficient. Unlike other extreme weather events, sea-level rise and its effects will take decades to be noticed. However, with the failure of the government to take action, livelihood, as well as lives of people will be at risk. Greenpeace is urging the government to enable cities and communities to build climate resilience by updating infrastructure, including establishing early warning systems, decentralizing climate information to enable more people to plan for climate impacts, and strengthening community-based disaster risk reduction and response to climate impacts.

References:

https://www.omlopezcenter.org/addressing-sea-level-rise-importance-of-historical-data-projections-and-local-adaptation-highlighted-by-experts-during-online-forum/

https://dfa.gov.ph/dfa-news/dfa-releasesupdate/29139-philippines-raises-alarm-on-impacts-of-sea-level-rise

https://www.rappler.com/environment/rising-sea-levels-top-list-climate-induced-risk-facing-philippines

https://icsc.ngo/ph-sea-level-rise-may-be-faster-than-global-average-climatologist/

https://documents1.worldbank.org/curated/en/657521468157195342/pdf/WPS4901.pdf

https://www.greenpeace.org/eastasia/press/6622/sea-level-rise-poses-economic-threat-to-asia-coastal-cities/

https://www.greenpeace.org/static/planet4-eastasia-stateless/2021/06/966e1865-gpea-asian-cites-sea-level-rise-report-200621-f-3.pdf

ttps://documents1.worldbank.org/curated/en/657521468157195342/pdf/WPS4901.pdf

https://reliefweb.int/sites/reliefweb.int/files/resources/climate-risk-country-profile-philippines.pdf

https://www.int-res.com/articles/cr/12_2/c012p097.pdf

https://www.ipcc.ch/srocc/chapter/chapter-4-sea-level-rise-and-implications-for-low-lying-islands-coasts-and-communities/

https://www.climatecentral.org/pdfs/2019CoastalDEMReport.pdf

https://www.nature.com/articles/s41467-019-12808-z.pdf

https://icsc.ngo/wp-content/uploads/2019/07/PAGASA_Observed_Climate_Trends_Projected_Climate_Change_PH_2018.pdf

Researcher at Climate Tracker

A research specialist and editor in a national government agency in the Philippines. Considers herself a polymer clay artist. Loves watching true-crime documentaries and drinking green tea with honey. Also speaks Filipino.