Of the options listed, changes in ocean currents have a more immediate impact on Earth's climate over a shorter period of time. Ocean currents can influence regional climates relatively quickly through their effects on heat distribution, weather patterns, and marine ecosystems.
In contrast, changes in orbital shape (eccentricity), tilt (obliquity), and solar output (solar irradiance) typically lead to longer-term climate changes and are associated with Earth's natural climate cycles over thousands to hundreds of thousands of years.