Extreme rainfall

Climate change is supercharging extreme rainfall. That’s the conclusion of a Washington Post investigation published last Monday.

As a result, the floods of the future will not be like those of the past. Expect floods to be vastly more devastating and deadly.

“As long as humans keep heating the planet,” scientists interviewed by the WP warned, “the warmer and more waterlogged atmosphere will deliver ever more intense floods.”

Warmer oceans resulting from climate change have supercharged the movement of moisture through the skies and that’s causing the super typhoons we are experiencing with more frequency and more ferocity.

The Post’s analysis, based on state-of-the-art weather data and computer models of the climate system, reveals that rising global temperatures have made the atmosphere more waterlogged, causing wetter and more dangerous storms.

The Post article talks of “invisible rivers streaming across the sky, massive plumes of moisture from oceans flowing across continents. These moisture plumes can result in a drizzle or a deluge.”

To determine where atmospheric water vapor has increased the most, The Post examined a metric called integrated vapor transport (IVT).

The Post explains: “Drawing on direct observations and estimates of wind speeds and water vapor throughout the atmosphere – captured by satellites, weather balloons, and airplanes, for instance — IVT helps meteorologists assess where moisture is coming from and how fast it is flowing. The higher the IVT in a region, the higher the chance of rainfall that can devastate communities below.”

It is these zones of rising moisture that are at greatest risk of unprecedented floods from above. According to The Post, moisture flows in the Philippines have increased by 7.8 percent since 1992, more than the global average.

Also, around 72 percent of our country’s land area is considered a hot spot where moisture flows have increased significantly and frequently produce heavy rain.

Water vapor in the atmosphere increase in our increasingly warm world. The Post says this activates something which “doesn’t look like anything most humans have seen before.”

Few phenomena can be more destructive than a rush of water streaming from the sky. “It takes just six inches of moving water to sweep an adult off their feet. At twice that height, a flood can lift a car off the road and carry it away.

“We need a new appreciation of the power of water,” hydrologist Ed Clark, director of the National Oceanic and Atmospheric Administration’s National Water Center, told The Post.

“This much is clear: When a stream of vapor from a fast-warming ocean arrives above a community, the consequences can be catastrophic.”

On Oct. 29 last year in Spain, one weather station recorded a year’s worth of rainfall in just eight hours. The water rushed down hillsides, swelled the region’s rivers, and swept into the city of Valencia and its surrounding towns, causing floods even in places where no rain had fallen.

Survivors told The Post that the deluge was so fast and forceful it ripped the clothes from their bodies and smashed buildings to rubble. Videos showed vehicles spinning through floodwaters like toys.

Many of those killed in Spain were elderly residents who drowned when the torrent surged into their homes. It was Spain’s deadliest natural disaster in more than half a century.

The flow of water vapor through the atmosphere is a natural phenomenon. “It’s just the extreme versions that cause the most harm,” Christine Shields, a scientist at the University Corporation for Atmospheric Research told The Post. “And we know we will see more of these extremes with climate change.”

How must we address this new reality of killer typhoons? The Post article offers suggestions:

“It means engineers must design bridges and culverts to handle storms beyond anything in the historical record. Planners must institute policies to keep people out of the most dangerous parts of flood plains. Meteorologists, emergency managers and local officials must develop better ways to warn residents and help them move to safety.”

All these reminded me of the foresight of my former boss at the Lopez Group. The late Oscar M. Lopez was warning of the catastrophic dangers of climate change before it was fashionable.

OML placed his money where his mouth was by funding the establishment of the Oscar M. Lopez Center for Climate Change Adaptation and Disaster Risk Management Foundation (OML Center) in 2012.

The OML Center was a pioneering academic institution championing science-based solutions for climate change adaptation and disaster risk management. The center aims to generate the science and technology needed for building resilient communities in the Philippines, a country highly vulnerable to climate impacts.

OML viewed the climate crisis as a critical challenge that businesses must address proactively, emphasizing that companies should focus on solving human and planet problems rather than profiting from creating them.

A central tenet of OML’s approach was that effective climate action requires a strong scientific basis. The OML Center, for example, is a pioneer in producing localized climate data and reports, such as the Philippine Climate Change Assessment (PhilCCA) report and the annual “State of the Philippine Climate” (SPC), to help decision-makers at all levels make informed, climate-smart risk management decisions.

Of course, we also now have the UP Resilience Institute whose Project NOAH has a treasure trove of up-to-date data that could guide decision makers in government and business to make informed decisions that take climate change risks in mind.

From the OML Center studies and data available from the UP Resilience Institute, we have the tools to deal with the new normal. Flood control projects should be science-based, not a pork barrel insertion.

About P26 billion has been spent on flood control projects in Cebu according to its governor. Yet, we saw last Tuesday so much suffering and economic loss. The high cost of corruption and the failure to use science in planning flood control projects is simply criminal.

Boo Chanco’s email address is [email protected]. Follow him on X @boochanco