Why the Caspian Sea is shrinking

On a beach just outside the Azerbaijani capital Baku, a pair of deserted swings creak back and forth in the wind.

They were built to be close to the water of the Caspian Sea. Now the ground beneath them is parched, and they are just relics of what once was there.

Less than 20 years ago, the land beneath them under the water of the "Mother Caspian", as they call it here.

It is the world's largest inland body of water and the lifeblood of the five countries that surround it.

But the whole sea is shrinking, and on this sliver of land in the Absheron national park, the shoreline is now 200 metres away.

"It is sad… even heartbreaking sometimes," said Elana Alizade, who used to play on other beaches around Baku.

"This is the place where as a kid we first discovered what biodiversity is, where we first saw snakes. We used to see turtles, different kinds of birds. We used to play with sand."

"And they were very narrow beaches. Now it's like we are in a different land."

Scientists are only just starting to understand why.

Migration warning

Water levels in the Caspian Sea, which sits below sea level, have always fluctuated, as tectonic shifts change the shape of the basin.

But they have been falling almost continuously since 1996, and faster still since 2006.

Already fisheries are falling, agriculture is being disrupted by the increasingly salty water and the critically endangered Caspian seal is facing extinction.

By 2100, the Caspian Sea's water levels could plummet by between 9 and 18 metres, various studies project.

"This is more than an environmental crisis. It is a human crisis," warned UN Environment Programme (UNEP) chief Inger Andersen at an event about protecting the sea during COP29 in the capital Baku this week.

"Without urgent action - including global action to slash greenhouse gas emissions - we could see as many as five million people displaced from the Caspian basin by mid-century."

Detecting fingerprints

Until recently, scientists were unsure why the water had been receding so quickly. Now they detect the fingerprints of climate change.

Hotter air temperatures and shifting wind patterns are licking more water from the top of the sea.

Warmer air is also drying up the flow in some of the main rivers that feed it, said Ms Alizade, who is now a climate change consultant for WWF Azerbaijan.

But there is more to it than that.

The water that flows in is already stressed by agriculture, population growth, and 14,000 dams in surrounding rivers, including the River Volga, which feeds the Caspian with 80% of its water.

"It's a microcosm of the global environmental problems that we're seeing," said Elizabeth Sellwood, a senior adviser at UNEP who worked on a recent report commissioned by Azerbaijan ahead of COP29.

"Five littoral states are experiencing major and disruptive changes that are driven in part by climate change and in part by many other factors."

The sea is even home to something that is driving its own destruction.

It rests on top of another key asset for the region: rich oil and gas reserves. Azerbaijan's portion provides 60% of the government budget.

But drilling for these has both polluted the water, and burning them is driving more climate change.

Asked if Azerbaijan accepted its fossil fuels were contributing to the problem, deputy ecology minister Umayra Taghiyeva said: "The problem is global."

She added: "The climate system is very complex... for example, a significant source of pollution may be evident in one continent of the planet, but the effects... can be felt anywhere."

The change has a "huge impact on coastal communities", said Ms Alizade.

Locals don't know whether to move infrastructure, like those swings, nearer the water because it keeps receding, she said.

The Middle Corridor shipping route that transports goods between east and west is also disrupted. Shallower water means ships have to carry lighter loads and make more journeys, causing more emissions.

At COP29, the five countries that share the Caspian agreed to work together to preserve the sea's resources, tackle climate change impacts, and collaborate on science, Azerbaijan's ecology ministry said.

But the group said little about tackling the growing cause: climate change, driven by fossil fuels.

"Adaptation can only go some way to help countries in the region," said Ms Sellwood.

But cutting emissions is "absolutely essential", she added.

(c) Sky News 2024: Why the Caspian Sea is shrinking