According to a new analysis from the journal Nature Communications, the Atlantic Ocean’s sensitive circulation system has become slower and less resilient. Scientists are concerned that the Atlantic Meridional Overturning Circulation (AMOC) could collapse any time between 2025 and 2095.

The AMOC plays a critical role in transporting warm, salty water from the tropics to the North Atlantic and sending colder water back south along the ocean floor. Because Arctic ice is melting at a rapid pace due to global warming, there is an overabundance of cold freshwater in the system, putting it in danger of irreversible collapse. Such a collapse could dramatically alter weather patterns, lowering temperatures in North America and Europe, propelling severe storms in the tropics and elevating sea levels on the U.S. Atlantic coast.

To measure the AMOC’s strength, scientists use buoys and proxy indicators, such as microscopic organisms and tiny sediments from the seafloor, and according to the data, it is at its weakest state in more than 1,000 years. Other experts suggest that the entire ocean system must be studied to more accurately predict the effect of these AMOC changes.