The use of two frost series (Dijon-Ouges and Besançon Observatory), and a serie of 120 years of temperature in Besançon Observatory, allowed restoring a tendency of global warming. This appears clearly since 1885 on the series 1885-2004 (Besançon). It can be interpreted as the result of natural warming on which is superimposed, in the second half of XXe Century, a global warming attributable to the human action. It is within this tendency completed with normal variation in successive years that the heat waves and scorcher of 2003 are situated. |