Commentary: Spain’s flooding tragedy is a small taste of what climate change has in store

LONDON: There’s no disguising the floods in Spain as anything other than a jaw-droppingly extreme weather event. The worst affected areas saw more than 400 litres of rain per square metre fall in just eight hours on Oct 29. As rescue and clean-up missions continue, the carnage is a small taste of what climate change has in store for us.
The death toll has surpassed 200, a number that’s likely to increase as relief efforts continue. A rapid partial analysis of the deluge by World Weather Attribution, an academic collaboration examining extreme meteorological events, estimates that human-caused climate change made the rainfall about 12 per cent heavier and doubled the likelihood of a storm of such intensity. 
There’s justified rage over a slow response from the Spanish authorities, along with conflicting accounts of the timing of alerts.
The civil protection agency in the Valencia region failed to send an alert to residents’ phones until after 8pm, by which point some streets were already underwater and people in grave danger. Maribel Albalat, the mayor of Paiporta, a town in the affected region, described the situation as “a trap” because many residents decided to enter underground garages at the worst possible time in an effort to move their cars to higher ground. 
Rather than taking responsibility for mistakes, leaders of regional and central governments are pointing fingers at each other. When Prime Minister Pedro Sanchez and King Felipe VI finally visited Paiporta, the reception was hostile.
We won’t know exactly what went wrong in Spain unless there’s an inquest, but this isn’t the first time that flood warnings and responses have been found lacking in Europe.
In July 2021, flash floods in Germany killed 189 people. An analysis of the flood alert system found it to have serious weaknesses, with survey data indicating that many residents didn’t receive a warning, or underestimated the magnitude of the deluge, while up to 50 per cent of those that were warned didn’t know what steps to take to protect themselves and their property.
As the report says, warnings are only helpful if the people in flood-prone areas and civil protection agencies “receive and notice the warning in time, trust the warning, understand its content, and know how to respond and behave adequately”. That wasn’t the case in Germany; the shortcomings were clearly repeated in Spain.
Providing effective forecasts and warnings can be challenging. While weather models these days are fairly accurate, it remains extremely difficult to predict precisely where thunderstorms will strike and whether the rain will translate into flash floods, as it depends on many local variables such as topography, infrastructure and surfaces.
It’s made more difficult by the fact that we’re seeing rare events more often because of climate change. It’s hard to predict what the impact of a year’s worth of rainfall in just eight hours are when it’s never been observed before. That’s true for both forecasters and the public.
While generating more precise forecasts would be helpful, we’re also often not communicating the information we already have effectively enough.
Improving messaging is quicker and easier than developing new weather models, but requires coordination between multiple stakeholders – meteorologists, local authorities and even businesses, who can all play an important roles in passing on threat information.
This is a growing area of science. As behavioural economists have found, people don’t always behave rationally. For instance, during a deadly 2013 tornado outbreak in Oklahoma, thousands of people fled their homes in cars despite years of messaging about the dangers of encountering twisters in a vehicle.
Weather warning systems are now being reviewed. Should there be a new category of alert above red for really serious events? How explicit should messaging be in terms of telling people what to do? How should risks be communicated?
The prospect of life-threatening flash floods is more readily understood than predictions of 400mm of rain. But there’s a balance to be struck: Being overly cautious and sending too many alerts may lead to distrust or warning fatigue.
Typically, forecasting, warning and response systems will see a burst of funding after an event like the Valencia floods. For a while, people will pay more attention: The response to the flooding in Barcelona this week may have been very different had people not just seen how serious the situation was a few days prior. 
On Tuesday, Sanchez pledged a relief package of €10.6 billion (US$11.5 billion), including direct aid for households and funds for city governments to pay for repairs and reconstruction. But what’s needed is investment to ensure Spain is ready for future rainfall extremes.
After all, to stay resilient, communities need to prepare for these events before they strike. People should know whether they’re at risk from flooding before rain is even forecast.
Authorities should have action plans for road closures and emergency service responses. Cities need to be built with space for water to reduce the risk of flooding in the first place. Integrating alerts with other platforms – Google Maps, for instance – could help nudge people toward safe and protective behaviours; warning systems and those who run them need sufficient investment. 
When a densely populated urban area is deluged by rain, the impacts are going to be large. But well-functioning forecast and alert procedures can save lives and reduce damage from extreme weather events.
The climate crisis isn’t going away; the disaster in Spain should be a wake-up call. We need to be equipped for the next time – and the next and the next.