Publication Date: August 3, 2023
Source: DIE ZEIT
In many regions of the world it is too hot and too dry these weeks. But the consequences of the climate crisis are particularly evident in the Mediterranean.
By Fritz Habekuß and Maximilian Probst
If you ask climate researcher Wolfgang Cramer how he sees the future of the Mediterranean region, he borrows a word from astrobiology, the science of life on other planets, for his answer: “habitability”. It means habitability. “We are starting to look at the conditions under which humans can still live in the region,” says Cramer. “So far we haven’t used the word habitability.”
Cramer is a professor of global ecology, heads a research institute in southern France and has been writing the world climate report for 25 years. Has the current summer surprised him with its records? “No, not at all,” says Cramer, “unfortunately it’s all within the predictions.” So it seems the Mediterranean has to adjust to what is happening right now in Turkey, Algeria, Morocco, Croatia, Italy and Greece. To weeks of temperatures above 40 degrees, to permanent droughts, to burning forests and fields.
Countries of three continents form the coasts of the Mediterranean, three world religions meet here, different cultures and political systems – a space of differences since time immemorial. What does not fit into it: prehistoric history in Sardinia, Egyptian pyramids, Greek cities on the Italian boot, Roman antiquity in Lebanon, Arab architecture in Spain, Jewish scholarship in North Africa, Norman church building in Sicily, Turkish Islam in the Balkans. This is because, wrote the great French Mediterranean historian Fernand Braudel, the region is “a very ancient meeting place where, for millennia, everything that existed met and helped shape, transform and enrich its history: people, beasts of burden, chariots, goods, ships, ideas, religions, ways of life.” The Mediterranean is a hotspot of civilisation.
In view of this diversity, one could say: the region appears united above all in the imagination of those for whom it is a sunny place of longing. Tourists, for example. Not only because of their cultural treasures dating back thousands of years, but also because of the climatic conditions, many countries with Mediterranean coasts are among the most popular travel destinations in the world. For some years now, however, something new has united the region: the Mediterranean is a hotspot of climate change. The idyll is masked by the deep red of temperature maps and forest fires.
The 1.5-degree threshold, the degree of warming that, according to science, is still tolerable for the world, has already been exceeded in the region. Measured against pre-industrial times, it has warmed 0.4 degrees more than the global average. This is currently 1.2 degrees. The pattern behind this seems stable: according to the forecast, warming here will also be 50 per cent greater than the global average in the coming years. A study from 2018 predicts that heat waves in the eastern Mediterranean could now occur several times a year instead of every two years as before.
And they will affect more and more people: Currently, a good 500 million live around the Mediterranean. By the middle of the century, this number is expected to have risen to 650 million.
The warming of the climate has a massive impact on the water balance. Each additional degree reduces the amount of precipitation by several percentage points – and this in a region that is already suffering from drought, especially in the south (North Africa) and east (Turkey), where agriculture is intensifying and cities are growing. It is quite possible that the largest lake in the region, Lake Beyşehir in Turkey, will have dried up by the 2040s.
Rainfall decline of 20 to 25 per cent?
Where does this extreme heating come from? Climate scientists Alexandre Tuel and Elfatih Eltahir from the Massachusetts Institute of Technology (MIT) provide an explanation. According to their research, two factors are intertwined: the peculiarity that a large body of water is surrounded by land masses. And a change in the upper troposphere that leads to more high pressure over the Mediterranean and less precipitation. “That’s where the Mediterranean has been unlucky,” says Elfatih Eltahir.
The decisive factor is that there is too little rain in winter. Exactly at the time when rainfall should be at its highest in the Mediterranean. As a result, the soils dry out and the cooling effect on the weather in summer does not occur. “We have seen this recently in Spain: Extremely dry winters in 2021 and 2022 were followed by heat waves,” says Alexandre Tuel.
The pattern described is unusual: almost everywhere in the world, the climate crisis leads to more precipitation. This is because hotter air absorbs more moisture, which later falls to earth as rain. But here, the humid air remains suspended over the sea instead of circulating and then raining down.
There is also another factor, explains Piero Lionello, a climate researcher at the University of Salento in southern Italy. In winter, storms bring rain to central Europe and have so far reached the Mediterranean region via a branch. However, this branch is shifting further north due to climate change, so that the storm no longer reaches the Mediterranean.
The zones most affected by the lower precipitation are those south of the 40th parallel (where Rome lies, for example). Nowhere in the world is the decrease greater. Northwest Africa, the MIT authors write, will have to adjust to 30 to 40 percent less precipitation in winter. Countries like Morocco, which are already extremely dry, will be affected. For the eastern Mediterranean, on the other hand, the researchers predict a 20 to 25 percent drop in rainfall. There, from 2007 to 2010, there was a drought of historic proportions, with consequences as far away as Europe: In Syria, farming families fled from the drought to the cities, which exacerbated the social and political conflicts in the country. When civil war broke out in 2011, hundreds of thousands sought refuge in Europe.
Societies will be able to adapt to some of the consequences; agriculture, for example, has great potential to do so: irrigate more efficiently, grow more robust varieties. In other areas, the possibilities for adaptation are limited – for example, in the case of rising sea levels. If the sea level rises by one metre by the end of the century, as many forecasts predict, entire cities will be directly affected. Venice is only the best-known example. A 2018 study concluded that of 49 world heritage sites located in low-lying coastal areas, 37 are already at risk from flooding and 42 from coastal erosion. These include the Medina of Tunis, the Old Town of Dubrovnik and the villas of Renaissance architect Andrea Palladio near Vicenza.
It is not only humans who will feel the effects of climate change. “Many ecosystems have very little chance of adapting,” says Piero Lionello. “Already today, masses of animals are dying regularly in the Mediterranean due to heat waves, plus ocean acidification.” On land, the heat waves and droughts in turn form the breeding ground for forest fires. It is true that the number of fires in the European part of the Mediterranean has declined over the past 20 years because countries have stepped up their fire-fighting efforts. But when there is a fire, as the data of the European Forest Fire Information System show, the fire spreads faster and eats up more area.
Most forest fires are caused by deliberate or negligent arson and could be prevented. Nevertheless, there is a connection between the fires and the climate crisis, says climate researcher Friederike Otto from Imperial College London. She collaborated on a study showing that the current heat wave in Europe would “practically never” have occurred without climate change. Regarding the recent forest fires, she says the past few weeks have created the conditions. Otto calls it “fire weather”: high temperatures and drought, plus wind. The first two factors have increased – and so has the risk of forest fires.
The example shows that it is not only physics that is decisive, but also how societies deal with the climate crisis. The drought and the fires are hitting a space of differences in the Mediterranean that are not only social or cultural, but also economically considerable. In the north (France, Italy), per capita income is three to five times higher than in the south and east (Morocco, Tunisia, Lebanon). Climate change could further fuel this divide. Those who lack the means to adapt to climatic exacerbations will fall even further behind.
The Mediterranean region is becoming a community of destiny. The problems triggered by the climate crisis are similar everywhere. What differs is how well the individual countries are prepared for it. Adaptations, wherever they are possible, will be essential for survival. But the gap between European countries and many others is large, not only economically: climate data is also many times better in the North than in the South, and with it the knowledge of what exactly the century will bring.
In this way, the Mediterranean can also be read as a laboratory of change. What is happening on a large scale in so many places in the world is reflected here on a small scale. It also reflects what is needed in the future: cooperation. Although a Union for the Mediterranean has already existed since 2008, it is not powerful. So far, nothing has come of the idea of a G10 Mediterranean initiative.
The Romans once called the Mediterranean Mare Nostrum: our sea. They used the term to express their dominion over the entire area. Climate change is pushing to fill the term with new life. For the people who live along the Mediterranean, there is a need for quick-witted alliances – for a rapid transition to renewable energies (there is enough sun) and effective protection of the life-sustaining ecosystems.
Tourism can help itself, flexible as it is. Holidaymakers will then come to their place of longing in spring and autumn instead of in the sweltering heat of midsummer.
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