What causes the uneven insolation that results in global wind currents?
The increase of the greenhouse effect worldwide causes what was called global warming. At the present time global warming is more frequently called global climate change as the effects may be more complex (from the human point of view) than simple warming. Some areas may be warmer, some colder, some wetter and some drier as changes to ocean currents and air currents modify the distribution of heat and moisure around the world.
Surface currents are caused by wind, and affected by the rotation of the Earth and the gravity of the moon (tides). When the oceans are deep, convection within the layers can also affect the flow of currents. * While wind currents are greatly affected by uneven heating of the Earth's surface, there is no corresponding heating of the ocean bottom by the Sun. So currents do not form spontaneously at depth.