“I think this drought will end overnight with a downpour of very heavy rain”
The SMC makes a cautious analysis of the semi-arid zone in Catalonia.
We have been cautious. And to be rigorous, we base our analysis on a 30-year period. That’s why we updated the analysis for the 1991 to 2020 period because the previous one covered 1960 to 1990, and the climate has changed a lot since then. We have updated the data, and so every time we say “the temperature has risen” or “it’s rained more than would be considered normal”, we are basing our comments on the past 30 years, not during the time of our parents, when the climate was quite different. Now we can say with certainty that, in the past 30 years, the temperature has risen by one degree and the semi-arid zone has increased in size.
What are the main features of climate change today?
Catalonia is more arid in every way. Some seasons like the summer are longer, which means spring and autumn are a little shorter, and winters are less cold. In terms of precipitation, it generally rains less. This does not prevent random episodes of very intense and very concentrated rain, which overall can make a year rainy, but the rainfall comes in a few concentrated moments rather than in a continuous manner as in previous years.
Is the extension of the semi-arid region into central Catalonia caused by the fall in precipitation?
Yes. When I was a student, the wettest parts of Catalonia were the counties of Girona and the north of Barcelona, while the driest part was Lleida in the west. In the past three years this has changed radically. The River Ebre reservoirs are now much fuller than those of the interior. We’re finding that there are fewer episodes of rain in the east.
Does this influence the extent of this semi-arid zone?
The record dry weather of the past three years suggests so. The fact that we have few episodes of rain from the east has had a major influence. And let me point out that Catalonia’s wettest town is only 200 km from the driest, and both are in the Lleida region, which are the towns of Espot and Ribarroja.
Can we expect the semi-arid areas to extend in the future into the neighbouring counties of Catalonia’s interior?
The climate projections that we’re working on indicate that the main changes in terms of reduced precipitation will be in the Pyrenees and Pre-Pyrenees. But if we talk about semi-arid areas we also have to think about places in the interior of Catalonia. In fact, our projections for the second half of the century we’re seeing already, with drought in the past three years.
Is this severe drought an exceptional episode or is it part of a trend?
I’d say it’s a new trend. We have data from the early 1800s, but they are based on local and church records. If we rely on scientific data, we have records since 1916, and since then the current drought has surpassed the record drought of 2006 in both territorial extent and intensity. We had forecast drought of this magnitude for later. Everything seems to indicate that the situation will get worse if we don’t make changes. This doesn’t mean there will be no rainy years, but the intensity and frequency of these droughts will be greater. The exceptionally high temperatures of 2022 and 2023 were forecast for the second half of the century. Without doubt the Catalonia of the future will be much warmer, with more tropical nights, which will affect more areas. Until now the usual areas of high night temperatures were the coastal areas due to high humidity. But now nights like these have extended inland.
We still have a drought but there were floods in Libya, Greece and Italy.
Everything makes me think our drought will also end overnight with an downpour of very heavy rain, because we have similarities with these areas, which have recovered from an extensive and intense drought.