Freshwater from Greenland’s melting ice is slowly mixing with the salty ocean, threatening the world’s low-lying lands. Sea levels are rising. Thermal expansion alone caused the oceans to rise by 20 centimeters during the 20th century. Everything is shifting.
Coral reefs, for example, are extremely sensitive to even the slightest change in water temperature—30% have already vanished. They are a vital link in the endless chain of life.
In the atmosphere, powerful winds are changing course. Rainfall patterns are being disrupted. Climate zones are shifting. The people of low-lying islands are the first to be affected. Their anxiety is growing—some are already searching for new land to call home.
What will the world’s megacities do if sea levels keep rising? Tokyo—the most populous city on Earth—stands directly in the path of this change. Year after year, scientists issue increasingly dire warnings. Coastal plains are home to more than 70% of the world’s population. Eleven of the fifteen largest cities on the planet sit on coasts or river estuaries.
As the seas rise, saltwater will seep into underground reservoirs, cutting off access to drinking water. Mass migrations will be inevitable. The only uncertainty is how far-reaching they will be.

Excerpt from the film A Thirsty World
by Yann Arthus-Bertrand, Baptiste Rouget-Luchaire, and Thierry Piantanida
© 2012 Hope Production

When the Sea Rises

The ice at the North and South Poles is melting—little by little. The oceans are getting warmer and taking up more space, like balloons swelling in the sun. Over the past century, the sea has risen by 20 centimeters!
Coral reefs don’t like these changes. Many have already disappeared, taking the fish that lived there with them. The wind is shifting, the rain no longer falls as it used to. Some places are becoming too dry, others too wet. People on low-lying islands are worried—one day, their homes might disappear under the water. And the big cities near the sea? If the water keeps rising, it will be harder and harder for them to stay dry.
What can we do? We can’t stop the sea… But we can make space for those who will have to leave their homes—and welcome them as new neighbors.

© Couleurs Grands Lacs – Text | © Armand Amar – Music