I think any sort of change in the climate that lasts for a very long period of time can affect regional climate changes (eg. mini ice ages). An example of regional changes would be the country of Iceland. Iceland has periodic volcanic eruptions that can even cause the grounding of planes, however, these type of regional disruptions may not reach other continents in forms of changing temperatures. The sea, however, is a predominate cause of temperature changes around the world, in my opinion.