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The ongoing scarcity of precipitation causes meteorological drought, which generally affects large zones and generates the rest of droughts: hydrological, agricultural, socioeconomic, etc. According to the AEMET (Spanish National Weather Agency), Spain has been in a situation of meteorological drought since January of 2022 (winter 2022/2023 climate balance sheet).
Storing water in reservoirs is essential to manage this valuable resource and be sure that we can supply it both regularly and in times of drought. Within this context of climate change and scarce precipitation, the amount of stored water has reduced in recent years, and this trend is plunging downward.
At the beginning of this hydrological year, 1 October 2022, which is when a typically Mediterranean climate such as our own is at its lowest, Spanish reservoir reserves were at 14,944 hm3, which is 32% of total capacity. And in 2023, after an extremely dry spring (the second driest since 1995), and despite the late rains in May, at the beginning of the meteorological summer, the reservoirs were at 47.4% capacity, 21% below the average of the past 10 years.
This reduction in the amount of water stored in reservoirs is accompanied by increased extreme temperatures, which stress periods of drought and complicate management of reserves.
In this vein, according to the World Meteorological Organization, world temperatures will break records over the next five years. The cause: not only greenhouse gas emissions caused by human activity, but also the end of the natural phenomenon La Niña in March 2023, which will foreseeably be followed by El Niño in upcoming months. The El Niño phenomenon normally goes hand-in-hand with increased temperatures around the world the year after its formation, meaning in 2024.
Mid-long term, according to models made by the Intergovernmental Panel on Climate Change (IPCC) for an intermediate emissions scenario (with current emissions reduced to a certain extent, but without a drastic change in energy models), from now until 2100 there will be a pronounced reduction in precipitation in the Mediterranean region, with decreased snowfall and uncertainty in terms of the evolution of extreme precipitations.
The situation we have just described is accelerating processes like desertification, which can be defined as degradation of land in arid, semi-arid, and sub-humid dry lands, the result of factors such as climate variations and human activities. In this context, an increase in the aridity index on the Iberian Peninsula is predicted, where broad zones in the southeast and centre of the Peninsula will join the semi-arid and arid categories at the end of the century.
In order to halt this desertification process, the Ministry for the Ecological Transition and Demographic Challenge drew up the Estrategia Nacional de Lucha contra la Desertificación (National Strategy for the Fight Against Desertification) in 2022, which adapts the Programa de Acción Nacional contra la Desertificación (National Action Programme Against Desertification) (PAND, 2008) to the new international agenda with sustainable land management measures and measures to restore desertified land, in addition to other measures, such as improving tools for risk management and decision-making in the fight against this phenomenon.
It is precisely within the international sphere that we find interesting initiatives to attempt to reverse this situation, such as the Great Green Wall in Africa. This is a project promoted by the African Union to fight the impact of desertification and environmental degradation, supported by the United Nations and the European Union. It involves 20 Sub-Saharan African countries and seeks to reforest a swath 7,000 km long and 15 wide to the south of the Saharan desert with different initiatives. The UN estimates that 33 billion dollars will be needed to restore the 100 million hectares by 2030. To facilitate funding flows, an Accelerator for the Great Green Wall has been provided. To date, it has raised 19 billion dollars for the project.
Initiatives like this one show us that it is in our hands to take action, to double down in our efforts for sustainable water management, and to promote imaginative and innovative solutions to contain and reverse the climate crisis toward a scenario with greater balance and respect for our environment.