As we head into the third decade of the 21st century, the threats posed by climate change only seem to be getting worse. Increasing atmospheric temperatures pose challenges from extended heat waves to ocean warming and rising sea levels, all of which place coastal communities at risk of extreme flooding.
While the Philippines does not significantly contribute to the ongoing climate crisis, the country is at the frontlines of extreme weather events which demonstrate the need for more and better climate action.
Sinking cities
Since the 1950s, carbon dioxide (CO2) emissions have continued to increase. Recently, the global pandemic has forced consumers to remain indoors and has brought structural systems to a halt, moderately and temporarily reducing our carbon footprint. According to a United Nations (UN) report, the construction industry accounts for 38 percent of all CO2 emissions, which largely contributes to rising sea levels.
Dr. Annadel Cabanban of Wetlands International Philippines explains the role of climate change in the rapid melting of polar ice caps, “With increasing atmospheric temperature, polar ice and glaciers on continents melt, and water flows down to [the] sea.” In the latest UN Intergovernmental Panel on Climate Change (IPCC) report, the rise in sea levels has become more apparent in coastal areas despite no significant increase in storm landfall. “[The climate situation] is severe and worrying,” she remarks.
By 2050, the IPCC observes that global sea levels will increase by 15 to 25 centimeters—putting millions of individuals at risk. Currently, coastal communities are exposed to increased flooding, erosion, and storm surges. Both structure and infrastructure developments most especially—like buildings, roads, and bridges—are at severe risk of damage due to these climate phenomena. If sea levels continue to rise, millions of coastal inhabitants will be forced to move further inland.
Amillah Rodil, a licensed environmental planner and architect, explores the varying impacts of extreme flooding in local communities. “[Coastal areas] are already prone to flooding and the land is also sinking because of ground subsidence and sea level rise,” she indicates. Coastal erosion—the gradual wearing down of the coastline or moving away of rocks, sediments, or soil due to strong waves or rising sea levels—also aggravates flooding in vulnerable settlements like Navotas and Malabon. Although inland areas are farther away from the shorelines, the changing environmental landscape makes flooding inescapable.
As concrete buildings and cemented roads dominate highly urbanized areas, cities become more prone to finding their way treading water. Non-permeable surfaces impede the flow of rainfall, resulting in flooding in low areas. These realities reiterate the fact that without coastal protection, many communities are at risk of permanent flooding.
Going with the flow
Mitigation measures play a vital role in the fight against climate change. In the case of The Netherlands, Dutch engineers spearheaded the Delta Works project that closed off estuaries—reducing the coastline and helping two-thirds of the nation’s population remain above water.
Meanwhile, Japan houses the largest underground flood diversion project in the world: the Metropolitan Area Outer Underground Discharge Channel in Tokyo. While these engineering marvels may offer better coastal and urban protection against rising sea levels, they also come with a hefty price tag.
More cost-effective mitigation strategies may come in various forms depending on the needs and capabilities of a community. Structural improvements, such as elevating houses on stilts, can prevent shallow flood water from entering houses. Settlements exposed to frequent storm surges may require flood walls, dikes, and dams to temporarily store excess water.
Dr. Diocel Harold Aquino, a professor of the University of the Philippines Institute of Civil Engineering, asserts that current structural and infrastructural designs are focused on reacting to catastrophic events rather than on mitigation and adaptation measures—which may come at a greater economic cost.
“We look into the typical hazards in the area and use this information fitted to the design parameters,” he expounds. Since Typhoon Yolanda (Haiyan), revisions have been made in the National Structural Code of the Philippines in anticipation of intensifying winds brought by tropical cyclones.
Aquino also stresses the importance of infrastructure-focused solutions against climate change. Infrastructure developments may have paved the way for flood protection systems, but using too much concrete has been detrimental. “If you build a solid infrastructure, then it would release a substantial amount of greenhouse gasses to the environment, exacerbating climate change,” he avers. Shifting toward sustainable practices could then potentially alleviate this concern.
It is also crucial to consider environmental sustainability in infrastructure design. Retrofitting, for example, is an adaptive measure that improves the vulnerable components of existing structures and infrastructures, which includes fixes that could possibly lessen carbon emissions.
In the future, living in floating houses does not seem like a far-fetched idea. However, the irreversible impact of rising sea levels removes the possibility of simply pulling the plug off the drain. As rising sea levels threaten to submerge our coastal cities, it is time to rethink our strategies.
Strength and resilience
While the first line of defense can protect us from unpredictable disasters, as climate change intensifies storms into super typhoons, the walls between us and the sea fall short of being sufficient.
Ecosystem services, such as coastal rehabilitation and forest conservation, can offer efficient protection systems against the climate crisis. “It is important [to] restore our ecosystem that provides us with free protection,” Cabanban affirms.
Although some structures and infrastructures can keep us safe amid disasters, it is also important to look at how we can combat these rapid changes by instead building infrastructure that can easily adapt.
Along with fixed flood control infrastructures, dynamic solutions can provide flexibility amid rapidly changing conditions. Flood plank barriers can be temporarily placed on doorways in anticipation of flooding and removed when not needed. In going against larger storm surges, movable flood gates—like the Rotterdam barrier in The Netherlands—can automatically block flood water when it reaches three meters beyond normal sea levels.
While one solution may be more effective than the other, resilience does not always mean choosing the ideal path. Economic factors could decide whether it would be attainable to consult new designs or improve the adaptability of current infrastructures. Strengthening systems could alleviate some concerns, but it may take away opportunities that brought the people near vulnerable areas. When the storm comes, we need to ensure that nothing and no one is left underwater.
EDITOR’S NOTE: December 14, 2021
The article has been updated to reflect more accurate statements from Dr. Diocel Harold Aquino, as well interpretations of his quotes, to uphold the technicalities of the covered subject matter.
