Climate variability, El Niño/Southern Oscillation, the North Atlantic and the Atlantic Multidecadal Oscillation with remarks on predictability:
The climate has always varied on a broad range of timescales and is governed by a multitude of external factors. Changing solar activity and volcanic eruptions, for instance, can change the climate, in the recent past more and more also mankind.
The climate, however, also fluctuates due to internal interactions within individual and between different climate subsystems. The chaotic atmospheric variability and its interaction with the oceans are of particular importance on the timescales on which anthropogenic climate change evolves. Here some basic concepts of internal climate variability are presented along with a few examples of internal climate modes.