When will we realize that the “new normal” of climate change has arrived? – 06/22/2023 – Fundamental Science

In the midst of the last Carnival, Brazil watched in amazement at the tragedy that killed 65 people and affected thousands more on the North Coast of São Paulo. In São Sebastião, the municipality most affected, the accumulated rainfall between the 18th and 19th of February surpassed 600 mm — that is, it rained more than 600 liters of water for each square meter. Now in June, the region is once again on alert for flooding because of heavy rains that have fallen again.

Make no mistake: this news will repeat itself again, and again, and again.

This type of episode, according to meteorologist Izabelly Costa, a researcher at the National Institute for Space Research (Inpe), is part of what scientists call the “new normal” of climate change. Costa is head of the Institute’s Weather and Climate Forecast Division (DIPTC) and says that what happened in São Sebastião was a point outside the curve in relation to the historical series of more than 30 years of rainfall that they have for the region — and to Brazil. “We haven’t seen anything of that magnitude in such a short period yet. But maybe this is one of the first episodes of what lies ahead,” she says.

Brazil is not yet ready for this new normal. A survey carried out by Agência Pública shows that, of the 27 capitals, 17 have no plans to face climate change. Adaptation is out of step with the urgency that the moment demands and with the knowledge produced by science.

“Many Brazilian cities have adaptation plans for this ‘new normal’. But many of these plans were not made by scientists, but by consultants or people who are unfamiliar with meteorology,” observes climatologist José Marengo, general coordinator of Research and Modeling at the National Center for Natural Disaster Monitoring and Alerts (Cemaden). “So often these plans don’t consider climate change or extreme events. It’s not that managers don’t take the issue seriously — it’s that they don’t have the knowledge,” says the researcher.

In Brazil there are ongoing projects with the objective of improving the prediction of extreme events. One of them is Nowcasting, which is the result of a partnership between INPE and Brazilian universities with the objective of implementing and operationalizing short and very short-term weather forecasts in the country.

“By severe weather we mean conditions like rain of more than 40 millimeters in an hour, hailstones larger than two centimeters and wind gusts above 80 km/h or that cause destruction,” explains the researcher. Very short term, in this case, means predicting the development and displacement of storm clouds accurately up to six hours before an extreme event happens.

“Nowcasting must be carried out for a small area, due to the complexity and amount of information that must be considered, but the criteria used need to be standardized. The idea is that based on the guidelines prepared by the Scientific Committee on Nowcasting, it can be implemented in the country,” says Costa.

Nowcasting is an evolution of SOS Chuva, a research project funded by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) focused on immediate forecasting of storms that ran in Campinas between 2015 and 2019 — and has a working app until today. All of this, says Costa, helps drive a change in the country’s culture, with a view to creating a broad, standardized and institutionalized database of extreme events. Once this bank is created, decision makers will be able to plan actions that increase the resilience of cities. There is a long way to go, but it is a matter of prioritizing what is most important. “This type of project never has the necessary financial incentive and the bank of severe events that we have today works on a voluntary basis,” observes Costa.

And then there is an even greater mismatch between the speed with which public authorities act and the speed with which knowledge production advances.

Nowcasting is a novelty that can greatly improve knowledge of extreme events in Brazil, but it comes in the wake of a weather forecasting process that already works and by itself already has conditions to avoid catastrophes like the one seen in São Sebastião. “What happened in São Sebastião was predicted. But if people receive alerts for any type of rain, it’s hard to believe that a storm is going to fall that could cause catastrophe. We need to improve what we want to communicate and how to do it, in addition to training the population to know what to do,” says Costa.

“Cities become more vulnerable and civil defense units may start to not act, perhaps because they start to think that the weather forecast and risk alert is unreliable,” observes Marengo.

What happened in São Sebastião marked Izabelly Costa. “Some extreme events are more difficult to predict, but this one we had a good forecast… In the end, in Brazil we are still not making good use of the information we already have,” he vents. “The hardest part of my job is convincing people that the country is lagging behind and we need to rush to implement high-precision systems for extreme events. For what purpose? To save lives,” she adds.

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Meghie Rodrigues is a science journalist.

The blog Ciência Fundamental is edited by Serrapilheira, a private, non-profit institute lucrative, what promotes science in Brazil. Subscribe to the Serrapilheira newsletter to follow the institute and blog news

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