SEARCH BLOG: GLOBAL WARMING
Yesterday, I began to look at the significance of 1 degree C warming over the past century. Today, I want to put that change in clearer perspective.
This graph is adapted from a website by Dr. Richard A. Muller of the University of California, Berkeley. You can click on the graph to see an enlarged image. Note the scale on the left is change relative to a 1950 baseline (approximately 15 degrees C) while the right scale shows absolute (measured) temperatures.
Based on the variation of average annual temperatures at the locations shown... and your understanding of what those climates are like... you can get a clearer perspective of what "warming" has meant... and judge for yourself what that means if the temperatures increase a little more.
Certainly, there will be geographical variations in the impact of any warming or cooling and 1 degree C change on a global scale will probably affect some regions more than others.
But just what those changes might be seem unclear at present... and may be only nominal. For example, the 1930s were characterized by hot "dust bowl" conditions, but the absolute temperatures as shown on the 120 year history were "cooler" than today's average... realistically, there really has been no appreciable change in average global temperature. Climate, quite obviously, is a combination of many factors. Crop failures of the 30s were not repeated in the past decade. There was no "obvious" relationship of warmth to rainfall during this period. Geographic features may dictate part of how a region reacts to temperature changes. Land use will modify the impact . Ocean temperatures and flows will also impact climates. Hot/cold and dry... or hot/cold and wet... were not simply a function of absolute temperature.Regardless, to put things in further perspective, when glaciers last roamed North America, earth's average temperature probably was much closer to Detroit's than Orlando's.
The present hyperbole is that we might experience more of what happened in the past 30 years... if you can distinguish that on the graph that displays regional climate averages.
Another good post with comments by Gavin Schmidt of RealClimate and Roger Pielke, Sr. of Climate Science is worth reading.
... more tomorrow....