A Brief History of Global Temperature Change

Scientist believe that the warmest global temperature average in the last 2,000 years prior to the 20th century probably occurred between 950 and 1100.  Warmer than average temperatures continued until about 1250.  This period, called the Medieval Global Temperature Optimum, was probably significantly below global temperatures since 1980 although some regional temperatures appear to have matched or exceeded recent levels in these regions.  A period of much cooler global temperatures followed the Medieval Global Temperature Optimum.  This period, usually referred to as the Little Ice Age, is generally considered to stretch from about 1350-1850.  Temperatures were cooler, arctic pack and Greenland's glaciers extended southward, and agriculture in Europe and North America was hindered and in many cases, devastated.

Many people today believe that humans are responsible for global warming.  While the evidence indicates that we may well be accelerating the process, the graph above clearly shows that temperature change is a natural occurrence.  Mankind may be able to slow the process if we curb our dependence on fossil fuel and continue to be sensitive to other factors that affect our atmosphere but natural forces will continue to have the greatest influence on our environment and we will never change that.