Estimation of Greenhouse Gas (CH4 & N) Emissions from Ruminants and Monogastric under Libyan Climate

Abstract

Because of the direct role of Green House Gases (GHG) in causing global warming، this study was undertaken to estimate GHG emitted by livestock under Libyan climate. The estimation was performed on ruminants (sheep, goats, cattle and camels) and mono-gastrics (horses, donkeys and mules) by applying certain equations according to the guidelines recommended for Tier 1 by (IPCC 2006). Tier 1 is primarily used to estimate GHG in the developing countries based on the total number of livestock in each country .In Libya, The animal Data used in this study for ruminants for period 2010 - 2019 was extracted from, while. Data for horses, donkeys and mules was taken for years 2015 - 2019 issued by Libyan committee of animal genetic resources (2020). Extrapolation of animal numbers for year 2030 and 2050 was done according to animal growth rate. The calculations showed that total gas emissions (methane and nitrogen) Gg CO2. Eq. from all animals was 3981 in 2019, and expected to be elevating to 4424 and 5665 Gg CO2. Eq. by year 2030 and 2050 respectively. Total nitrogen emission was slightly higher than methane during whole period (53%). Amount of methane emitted was higher in sheep than goat and cattle. In contrast nitrogen emission was higher in cattle than other animal’s .The contribution of mono-gastric animals does not exceed 2% of total emissions. The rate of gases emission is positively related to number of animals and to per animal head (the heavy head > lighter head), and inversely related to per unit body weight (the smaller the animal the higher the emission rate per unit of body weight (sheep &goats >horses &donkeys > cattle > camels). The differences in the results  of GHG emissions from livestock in numerous  developing countries  were due to variations in animal populations, emission factors, Gas warming potential (GWP) used to convert emission values to CO2. Eq. manure management (collection, storage and end use) and others. Most previous studies undertaken by developing countries recommended the need for updating the guidelines of using Tier 1 (IPCC 2006) to fit local and regional climate and livestock characterizations. However, using Tier 1 under existing circumstances is still more recommended for preliminary estimates to GHG emissions of livestock in developing countries. These estimates will help policy and decision makers locally and climate panels considering climate changes to establish local and global strategies to mitigate level of livestock GHG emissions. In addition, to ameliorate suitable climate for livestock to produce and reproduce to assist establishing local food security.