I have been taught that the changes in current were caused primarily by climate change but upon reading the conclusion of the paper named: "Observed decline of the Atlantic meridional overturning circulation 2004–2012" I am left baffled if climate change caused the change in the currents.
Citation for the paper : Smeed, D. A., McCarthy, G. D., Cunningham, S. A., Frajka-Williams, E., Rayner, D., Johns, W. E., Meinen, C. S., Baringer, M. O., Moat, B. I., Duchez, A., and Bryden, H. L.: Observed decline of the Atlantic meridional overturning circulation 2004–2012, Ocean Sci., 10, 29–38, https://doi.org/10.5194/os-10-29-2014, 2014.