The last breath of the Aral Sea
Sofía Rodríguez at the Aralkum desert
Sofía Rodríguez at the Aralkum desert

The story is well known. The gloomy fate of the Aral Sea was sealed at the beginning of the 20th century, when the most prestigious of Russian climatologists, Alexander Voeikov, defined it as a “useless evaporator.” However, it was not until the 1960s that this destiny began to crystallize before the incredulous eyes of the inhabitants of its shores. Most of the water from the two enormous rivers that fed the Aral Sea was diverted to meet the irrigation demand of the cotton crops that the Soviet Union promoted in Central Asia, which destroyed the delicate hydrological balance of the sea, which began to evaporate. It only took fifty years of agricultural exploitation to reduce it to 10% of its size. In less time than it took to depreciate a boat, the inhabitants of fishing towns in Kazakhstan and Uzbekistan saw the fourth largest sea on the planet and its most important freshwater fishery disappear, leaving them in economic and human ruin. Within a few more years, the Aral had retreated so far and so quickly from its ports and shores that for generations born after the 1980s, fishing or swimming in the Aral Sea is only something that appears in the longings of the elderly. In just three generations the sea had disappeared.

«The Aral Sea is still the protagonist of one of the greatest environmental catastrophes of the 20th century»
A journey through time through sediments

What was once the thermoregulator of Central Asia is now nothing but a desert. The ports still house their majestic cranes and ships, today, all hopelessly rusty. A landscape incomprehensible to the new generations who have never seen the sea and had to trade fish for camels. The inhabitants still wonder where the sea is, and they continue to believe, deep in their hearts, that one day it will return.

«The inhabitants still wonder where the sea is, and they continue to believe, deep in their hearts, that one day it will return»

But what if the most iconic environmental catastrophe of the 20th century still has a surprise in store for us? Beyond the Kokaral Dam, which partially saved the northern bay that bathed the city of Aralsk, all that remains is the gigantic wound that the hand of man has left there. The scar consists of a new desert of salt and extremely fine sand, which storms raise to infiltrate the noses, lungs, blood, and souls of the region’s inhabitants.

«The Aral Sea is now one of the largest living laboratories on the planet where the consequences of global changes can be studied»

Aralkum, the new desert, is nothing more than sediments accumulated at the bottom of the ancient sea and the salt that was deposited when the water evaporated. The sediments, accumulated over hundreds of thousands of years, hold the ecological memory of what was the Aral Sea and a treasure trove of buried carbon. The lakes and inland seas receive a large amount of material from the terrestrial ecosystems that surround them, and much of it ends up buried in their sediments. Some of this material is the remains of plants that once used atmospheric CO2 to grow. When rain and runoff wash these remains down into the lake sediments, an amazing thing happens: this carbon, originally in the form of atmospheric CO2, now rests trapped at the bottom of lakes and seas, accumulated as detrital material. This journey of carbon from the atmosphere to the bottom of lakes is part of the delicate and extremely complex planetary machinery that regulates atmospheric CO2 and, therefore, the climate.

«The heart of what was once the Aral Sea is now a mind-boggling landscape, causing an overwhelming mix of fascination and fear.»

But what happens when we dry up a sea? Will the carbon stay buried in the sediments, or will it be released back into the atmosphere? Unfortunately, thousands of lakes and inland seas are drying up as a result of our water consumption and climate change. Will this cause the carbon accumulated in the sediments of these lakes to end up in the atmosphere, accelerating climate change? Will the Aral Sea’s last gasp be a CO2 gulp that pushes us to the point of no return?

From ally against the climate crisis to carbon emitter

Read the full article pulished at Revista Mètode

Rafael Marcé. Scientific researcher at the Blanes Center for Advanced Studies CEAB-CSIC.

Laura Carrau. Biologist, documentary filmmaker and founder of the production company Mileva Films.