Introduction
As climate change continues to impact our planet, it’s causing a paradoxical effect on lakes worldwide. While rising sea levels due to melting glaciers in Greenland (7.4 meters) and Antarctica (5 meters West, 60 meters East) are a major concern, lake levels are also dropping at an alarming rate. In fact, 53% of the world’s lakes have decreased in size since 1992, threatening freshwater storage crucial for more than a quarter of the global population.
Case Studies
- Lake Pátzcuaro, Mexico: Once covering 118.73 km², it has shrunk to 68.33 km², losing 42% of its surface area and 33% of its volume. The island of Janitzio no longer qualifies as an island due to land connection, caused by climate change and human activities like water theft and irregular agroforestry (aguacate and berries).
- Lake Montbel, France: At 72% of its capacity in MAR2023.
- Lake Chad, Cameroon, Chad, Niger, and Nigeria: Lost 95% of its water since the 1960s.
- Aral Sea: Now only 10% of its size from 30 years ago.
The Caspian Sea: A Global Water Reservoir Under Threat
The Caspian Sea, encircled by Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan, is the world’s largest internal water body, measuring 1,200 km north-south and storing over 40% of the world’s lacustrine water. Its size is comparable to that of Japan or Germany, and it holds more liquid than the seven largest lakes globally.
Due to climate change, primarily through heightened evaporation and reliance on a single river—the Volga—for 80% of its water, the Caspian Sea’s water levels are declining. This trend has been noticeable since the mid-20th century but accelerated after 2000. By 2070-2100, the sea’s water level is projected to drop by 9 to 18 meters, causing the northern third (with an average depth of 5-10 meters) to disappear.
Impacts on Surrounding Regions
With prevailing northwest-southeast and southeast-northwest winds, the shrinking Caspian Sea will lead to less evaporation, fewer clouds, and uneven irrigation of the Pontic steppe—extending across Bulgaria, Moldova, Romania, Russia, and Ukraine. Bordering states are addressing this issue, as evidenced by the COP 29 declaration to foster cooperation and tackle water level decline. All countries within the lake’s basins, both contributing and receiving this precious resource, must participate.
The Importance of Lakes and Our Responsibility
Though lakes may seem localized, their significance is undeniable. The Caspian Sea’s vastness highlights how any reduced lake signifies lesser moisture. Every lake should be regarded as a shared human responsibility, emphasizing our duties towards the environment, lakes, water, and climate.
Rising seas and shrinking lakes are two sides of the same coin, both part of the global water cycle. We must recognize our interconnectedness and act responsibly to protect these vital resources.
Key Questions and Answers
- What is the impact of climate change on lakes worldwide? Climate change contributes to both rising sea levels and decreasing lake levels. This paradoxical effect threatens freshwater storage, crucial for over a quarter of the global population.
- How is the Caspian Sea affected by climate change? The Caspian Sea is experiencing a decline in water levels due to increased evaporation, reliance on a single river (Volga) for most of its water, and human activities.
- What are some examples of lakes affected by climate change? Lake Pátzcuaro in Mexico, Lake Montbel in France, Lake Chad, and the Aral Sea have all experienced significant reductions due to climate change and human activities.
- Why is the Caspian Sea important? The Caspian Sea is the world’s largest internal water body, storing over 40% of the world’s lacustrine water. Its size is comparable to that of Japan or Germany, and it holds more liquid than the seven largest lakes globally.
- What can be done to address these issues? Countries surrounding the Caspian Sea and other affected lakes must collaborate to develop strategies that mitigate climate change impacts, manage water resources sustainably, and protect these vital ecosystems.
