Journal of Environmental Science and Engineering B 1 (2012) 690-694 Formerly part of Journal of Environmental Science and Engineering, ISSN 1934-8932 Temperature Variations in Sidi Bel Abbes during the Last Three Decades Sara Lebid 1 , Youcef Amar 1 , Macho Anani 1 , Benyounes Djahed 1 , Kada Mouedden 1 and Christian Mathieu 2 1. Green Laboratory, Djillali Liabes University of Sidi Bel Abbes, Sidi Bel Abbes 22000, Algeria 2. Faculty of Sciences Jean Perrin. Artois University, Lens Cedex 62000, France Received: September 19, 2011 / Accepted: January 12, 2012 / Published: May 20, 2012. Abstract: The Mediterranean climate of the Sidi Bel Abbes city in northwestern Algeria has not been the subject of many investigations except some sporadic syntheses reports. However, climate change studying its most important parameters has not, at our knowledge, been the subject of a rigorous study. For this purpose this work intends to gather several temperatures ranging between 1980 and 2006 and find a mathematical model that tells us climate changes following changes in temperature during this time interval. Consequently and undesirably, the results confirm firmly the global greenhouse effect affecting our planet, but what seems rather puzzling is the fact that this warming trend has accelerated over time resulting in a changing climate toward warmer periods, for that reason a likely shift in the region of a semi-arid to tropical or arid regime overall, depending mainly on the evolution of the Azores anticyclone. Key words: Climate, temperature, heat quantity, global warming, greenhouse effect. 1. Introduction This work’s main goal is to study the variations of temperature as a climate parameter in the town of Sidi Bel Abbes and its suburbs. This town covers an area of over 20 square miles with a population estimated late 2010 to more than 230,000 inhabitants. It is located in north western Africa, north western Algeria north of the Mekerra river plain which takes its source right 80 km further south. The climate of this region is the Semi-arid Mediterranean type with hot summers and relatively cold winters due to the relative altitude of over average 470 m but also because it is situated in a bowl and the fresh winds of the Mediterranean blowing in the winter are relatively blocked by the Tessala’s chain which peaks at 1,070 m, straight 10 km north of the city, while the Daia mountains close the southern Corresponding author: Macho Anani, Ph.D., associate professor, main research fields: energy sources, bioinformatics, computational biology, environment and pollution. E-mail: anani66@yahoo.fr. horizon with regular peaks over 900 m. This creates a kind of microclimate that makes the city and its close region not fully completely open either to the effects of the sea or to the hot breath of the southern Highlands instead of the fact those days of frost as well as those of heat waves are still common. Climate could be defined as average physical conditions that occur in a given place, like temperature and precipitation quantity calculated according to 30 years consecutive observations, as defined by the IMO (International Meteorological Organization). It is, thus, identified by average values but also characterized by extremes measures variations. At a larger scale of the planet in a whole, the climate represents a complex machinery product, in space and time, of elements that constitute the different compartments of the atmosphere interactions successions, like atmosphere, lithosphere (earth), hydrosphere (set of oceans, lakes and rivers), cryosphere (ices of whole world) and biosphere (whole of living organisms and particularly vegetation). DAVID PUBLISHING D