One of the major ocean currents, the Atlantic Meridional Overturning Circulation (AMOD), is weakening. Ocean currents carry heat with the water. As that heat transfer changes, it changes the heating of the air and land that it encounters. In this case, less heat into the north Atlantic means a cooler Europe and a warmer Caribbean, which could also become worse winters in Germany and worse hurricanes in Florida. The downturn started at about the start of the Industrial Revolution, and may take some time to alter. In the meantime, we may just have to adapt.