As the global climate warms, isolated cooling trends can still occur, driven by disruption of regional circulation patterns or natural variability. While average global temperatures rise with global warming, a few region such as the North Atlantic Ocean have experienced cooling over the last century as a whole, though it has warmed over recent decades.
North Atlantic trends and projections
Such contributions to decreased density of the ocean surface layer in the North Atlantic could act to reduce deep ocean convection there and contribute to a near-term reduction of strength of Atlantic Meridional Ocean Circulation (AMOC). However, the strength of the AMOC can also be modulated by changes in temperature, such as those from changing radiative flux.”