3:46 pm today
By Laura Paddison, CNN
Clouds over the Atlantic Ocean.
In the North Atlantic Ocean, south of Greenland and Iceland, a large patch of water is doing something very strange. While the rest of the ocean heats up, it's been getting colder. A new study says it has the answer to this mystery - and it's an ominous sign the world is hurtling toward one of the most alarming climate tipping points.
The swath of ocean - dubbed the "cold blob" or "warming hole" - has cooled by nearly 1 degree Celsius since 1900.
