Consequences of climate warming in Euskal Herria

1998/01/01 Mintegi, Imanol Iturria: Elhuyar aldizkaria

• Ingurumena

The Euskal Herria of warm winter and warm summer could be a dream and the need to go to the Benidorm or Canary islands would disappear. In addition, our baserritarras should not be afraid of ice and would produce throughout the year what today only comes out in summer. But this temperate, in addition to its positive consequences, would have tragic consequences.

And if the climate is stormed, it will be temperate worldwide, in some more notable places, in others more modest. According to the measurements made and the computer models developed, one of the biggest effects of the greenhouse effect would occur in the high latitudes of our planet, totally modifying the local climates. As a result, both glaciers and ice hats in Antarctica and Greenland and other Arctic regions could probably be immersed in a geological lipar. This melting, on the one hand, would cause the appearance of large covered regions today, about tens of millions of square kilometers approximately, of ice and snow, but on the other hand, the dumping to the seas of a huge volume of water, thousands of cubic kilometers.

Water flows continuously to the sea due to river mouths, icebergs from glaciers in high latitudes and atmospheric precipitation. Likewise, the sea presents constant losses through evaporation and leaks to the interior, which compensates for the benefits, thus maintaining the sea level. However, if, as a result of a slight climate change, the world's snow and ice melt, the sea is not able to compensate for this rapid influx of water, so sea level will rise.

This is already happening, and although in geological history it has occurred with regularity, this time more than by natural causes, it may be due to the greenhouse effect caused by humans and, in addition, to a greater speed than has happened.

According to observations, the sea is rising at least one millimeter a year in recent years, but it seems that the speed of this ascent is accelerating. Of course, it is difficult to know the extent of this acceleration and, therefore, it is not easy to calculate the sea level increase in the coming years. Although the most conservative calculations claim that the sea will only rise half per meter in the next hundred years, there are researchers who claim the ascent, two meters and more. In short, let us not forget that in times of glaciations the sea level was between 100 and 200 meters below the current one and that the Basque coast was located a few kilometers from the current position.

This rise of the sea would have very serious consequences worldwide, especially considering that much of the population lives on the coast. On the other hand, facing the Basque Country, the rise in sea level would not have, in principle, many terrible consequences, since our country is mountainous and part of the population lives far from the coast. However, after a more relaxed analysis, there may be regions that increase their consequences. In our coasts abound the sea cliffs and in them the rise of the sea level would little change.

But, apart from the cliffs, we have the mouths of the rivers, the beaches, the urbanized areas next to the sea branches. For example, Biarritze-Baiona, Donostia-Hernani and Abra-Gran Bilbao are built with respect to the current sea level and any sea rise, both in the case of hard marejismo and in the case of high atmospheric precipitation, would produce a total impact. And we must not forget that geomorphology and current geodynamic processes are adapted to the sea level we have, but their ascent would change the balances that were formed over the centuries.

Even outside atypical climatological episodes, sea level rise would affect and alter daily activities. In this way, most of our beaches would remain on few occasions, since its upper limits are urbanized, assuming an unalterable wall, and the tape covered by the sand would be embedded or disappear under water, as happens in the winter tides on the beach of Concha. On the other hand, not only on the beaches, but also on the docks of our coastal towns, some constructions would be affected, so it would be necessary to carry out important work of protection and maintenance. These types of conditions would be particularly significant both in the lower part of the Nerbioi-Ibaizabal (Bilbao, Erandio, Barakaldo, Sestao,...) and in lands near the Abra.

In addition to the damage, the influence of the sea would reach places where it does not feel today, such as tides, and changes would occur in the associations of different aquatic beings, colonizing new niches or losing the necessary ones.

On the other hand, the changes, the inconveniences and the commented loss are many other possible but we still do not know them or we cannot measure them, since so far very little has been done in this field. However, considering the terrible disaster that sea level rise can only mean in our economy, we will have to start working as soon as possible to cope with what may come to us, even though we do not really know how much it will be.

The rise in sea level would not have, in principle, many consequences for the Basque Country, since our country is mountainous and part of the population lives far from the coast. However, after a more relaxed analysis, there may be regions that increase their consequences.