During Post-classical times, there is evidence that many regions of the world were affected similarly by global climate conditions; however, direct effects in temperature and precipitation varied by region. According to the Intergovernmental Panel on Climate Change, changes did not all occur at once. Generally however, studies found that temperatures were relatively warmer in the 11th century, but colder by the early 17th century. The degree of climate change which occurred in all regions across the world is uncertain, as is whether such changes were all part of a global trend. Climate trends seemed to be more recognizable in the Northern than in the Southern Hemisphere.