Temperature as climate change indicators and reference evapotranspiration in the western region of Libya

Abstract

Climate change is the main environmental issue all over of the world. Temperature is the main climate change indicator. The warming is the main feature of the climate change. Libya is one of the driest and the semi driest regions in the world, therefore the climate changeresearch should be the main research issue.The area of study is located in the north western region of Libya, where the most population of Libya is concentrated. The monthly basis historical temperature for long term data station in the western zone of Libya were obtained from the Libyan National Climate Centre (LNCC). Data of threestations were used to representJeffara plain from east to west (Misurata,Tripoli city, Tripoli A/P) in addition to Zwara, and data of two stations were used to represent Nefusa upland (Garian and Nalut). These stations are considered a good representative for the Western region, as they cover the north –west, north-east, south-west and midlands-east part of Western region. The entire climate database is divided into four periods; 1961- 1990 represents the recent historic prediction or baseline, while 2010- 2040, 2041-2070, 2070-2100 represents the short-term, middle-term and long-term future climate projections for air temperature. The mean of the temperature of the six stations were estimated to represent the mean annual temperature of the region. The results show that the annual temperature mean of the region shows an increasing trend. The regression equations shows increasing indicators for all stations and the expected temperature for the mid of years of short, mid and long term of the future which are within the expected rise in global temperatures of between 1.4 and 5.5°C by the end of the 21^sh century. The decade beginning 1990 has been the warmest decade where the warmest year is 1999 (in contrast to the global year 1998) in the instrument record for the region. The regression analysis shows an increasing trend of reference evapotranspiration (ET_o) with the time. Reference evapotranspiration ET_o for the mid of years of short, mid and long term of the future show as the temperature will increase the reference evapotranspiration will be increased too.