A series of ocean currents in the Atlantic drive heat northward and control much of the world’s weather. Scientists believe the current — called the Atlantic Meridional Overturning Circulation, or AMOC for short — will slow down this century due to global warming, and some fear the circulation might collapse entirely. The melting of the Greenland Ice Sheet could be a major factor in the future health of the AMOC. The World’s Host Carolyn Beeler traveled into a fjord in Greenland with scientists studying glacial meltwater to better understand what it could do to the AMOC.

This story originally aired on Oct. 1, 2025.