Higher temperatures turn Spain into a desert

Lavezzi Island (Corsica region, France). Photo: Daniel Pavon, IMBE, Aix Marseille University

The bad news is for investors who have gathered on the cheap to buy a cottage or apartment in the resort town of Greece or Spain. Climatologists warn that even with the limitation of the average global warming, we are waiting for a noticeable climate change in specific regions. If the increase goes according to the pessimistic scenario, the consequences will be very unpleasant. For example, Southern Spain will turn into a desert.

Under the 2015 Paris Agreement, under the UN Framework Convention on Climate Change, countries agreed to reduce CO ₂ emissions in order to keep warming within 2 ° C above the pre-industrial level, as well as “make efforts to limit the temperature rise within 1.5 ° C above pre-industrial level

It would seem - great. Countries finally agreed. The temperature will rise only a couple of degrees, and more will not grow. All is well.
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But climatologists add a bit of pessimism to this idyllic picture. They note that a global average temperature increase of 2 ° C means a significantly greater increase in average temperatures in certain regions. At the same time, daily highs reached extreme values. That is, on some days, the temperature on the street will be just deadly. The result of modeling this situation was published in January 2016 in the journal Nature by specialists from the Institute of Atmospheric and Climate Sciences of the Swiss Higher Technical School Zurich (Switzerland), the Research Center on Climate Change at the University of South Wales (Australia) and Loughborough University (United Kingdom), doi: 10.1038 / nature16542 .

The recent increase in global average temperature of less than 1 ° C has already led to a noticeable destabilization and disruption of many existing ecosystems, as detailed in the Fifth Assessment Report (OD5) of the Intergovernmental Panel on Climate Change (IPCC), especially in Part A.

Some regions of the world are at particular risk. Climatologists cannot confidently say in which particular regions of the world the temperature will rise especially when the average global level rises 2 ° C above the pre-industrial level. But if you extrapolate the current situation, the residents of some countries will have a hard time.

At the moment, the global average temperatures have risen by just 0.85 ° C relative to the pre-industrial level, but specifically in the Mediterranean, the increase was about 1.35 ° C. Even the optimistic scenario of the UN Framework Convention on Climate Change (the green box on the diagram) looks threatening for the countries of the region.


The colored rectangles on the graph correspond to the framework laid down in various scenarios of the United Nations Framework Convention on Climate Change for 2010–2100. Blue circles and blue vertical bars indicate the same frame for the Mediterranean region.

According to the forecast, the growth of average global temperature by 1.5 ° C or> 2 ° C - these are two completely different scenarios for the Mediterranean. Researchers from the European Center for Research and Teaching Ecology and Earth Sciences have prepared the result of a climate simulation under various global warming scenarios. The scientific work was published on October 28, 2016 ( doi: 10.1126 / science.aah5015 ).

Very few climate simulations before the end of the 21st century allow a climate increase of less than 2 ° C. The problem is that the Mediterranean is very sensitive not only to rising temperatures, but also to a shortage of fresh water. This means that further increases in temperature and drought threaten significant changes in plant diversity in the local ecosystem. As the historical reconstruction shows, for the Mediterranean, the upcoming drought will exceed all historical drought periods of the Holocene epoch, even taking into account the measurement error (the blue vertical boundaries in the upper diagram on the lower left). As it is known from past scientific works, droughts in the region contributed to the decline of civilizations in the Mediterranean . And these were droughts of a smaller scale than the one that expects the Mediterranean in the near future. Now the story seems to be repeated. Thus, the period 1998–2012 in Syria and other countries of the western Mediterranean was the driest in 500 years. Coincidentally, during this period, the social situation was heated.

Researchers emphasize that the Mediterranean is an important region of the world in terms of biological diversity. Here lives a diverse flora and fauna, there are sources of fresh water. Although this is a relatively small patch of our planet, but still I would not want to lose it.

The simulation of the Mediterranean biome map shows the historical reconstructions of the biome, the current situation and the forecast of how the ecosystems of the natural climatic zone will change under different global warming scenarios.



The simulations for the ambitious scenarios RCP2.6L and RCP2.6 do not show a significant biome change until the end of the 21st century, but the more extreme scenario RCP4.5 shows the expansion of the desert in North Africa, the degradation of alpine forests and the expansion of the hardwood vegetation in the Mediterranean. Probably, this scenario can be considered as the most realistic.

According to the RCP8.5 scenario, the southern regions of Spain turn into a desert, deciduous forests cover most of the mountains, and Mediterranean vegetation takes the place of deciduous forests in most of the Mediterranean. As seen in Figure 3H, climate change will affect the territory of Ukraine and Russia.

According to scientists, the only acceptable scenario for the Mediterranean ecosystem is the most ambitious scenario RCP2.6L, which provides for a sharp reduction in carbon dioxide emissions and an increase in average global temperature by only 1.5 ° C relative to the pre-industrial level.

However, life shows that scenarios that are optimistic for the environment are unlikely to be realized. Rather, the development will follow a pessimistic scenario. It should be noted here that climatologists did not take into account in their simulation other factors of human impact on the environment except for temperature increase: for example, pollution by industrial waste, soil erosion due to agriculture, etc. “Human participation can only exacerbate the forecast, and then our work will seem too optimistic,” admits Joel Guiot from the European Center for Research and Teaching Ecology and Earth Sciences (France), one of the authors of the scientific work.