text: As a geologist I would have to combine both. There is ample evidence of catastrophic events such as meteor strikes that have caused major extinction events in the earth's history, yet I believe that plate tectonics is a cyclical process that has been the basis of most earth processes. I would argue that earthquakes, most floods, and most volcanic eruptions are part of the uniformitarianist view, since they take place on our planet on a daily (even hourly) basis and are driven by the slow process of plate tectonics. Some floods, such as the filling of the Mediterranean or the Black Sea were more likely catastrophic, but did very little to change the earth in the big picture. Some major volcanic events may have changed the earth's climate for a period of decades afterwards, but are still minor over geologic time. Only when large numbers of volcanoes were erupting together over long time periods did they have potential to change the planet, and this fits easily into uniformitarianism.   \n\nThere is growing evidence that climate change may be more catastrophic than previously believed. Past climate change appears to have been quite sudden at times. This may be due to the nature of feedback within climatic systems that causes several factors to react together to accelerate the overall effects. For example, melting icecaps could shut down or alter major ocean currents, which in turn would accelerate atmospheric circulation patterns that cause warming. Some of these past warming events may have happened quite suddenly, yet much of climatic change has been related to plate tectonic motion (Wilson Cycles) and to Milankovitch cycles in the Earth's orbit that are quite regular. Slow movement of tectonic plates does cause changes in oceanic and atmospheric patterns such as ocean currents and even the jet streams so many of the factors of change are quite slow and gradual, making uniformitarianism as valid as catastrophism and pretty much requiring acceptance of both.