A major ocean current system in the Atlantic Ocean, which helps regulate the Earth's climate, has been weakening for nearly 20 years. Credit: NOAA

A major ocean current system in the Atlantic Ocean, which helps regulate the Earth's climate, has been weakening for nearly 20 years. Credit: NOAA

A major ocean current system in the Atlantic Ocean, which helps regulate the Earth's climate, has been weakening for nearly 20 years. Credit: NOAA