MEXICO'S CONTRIBUTION TO GLOBAL RADIATIVE FORCING BY MAJOR ANTHROPOGENIC GREENHOUSE GASES: CO2, CH4 AND N2O

Víctor Manuel Mendoza Castro, René Garduño, Elba E. Villanueva, Blanca Mendoza

Abstract

The IPCC (2013) gives simplified formulas to compute the radiative forcing (RF) resulting from the increase in anthropogenic greenhouse gases (AGG): carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and halocarbons. These formulas allow to compute the global RF of these gases relative to their pre-industrial (1750 A.D.) concentrations, and are used in this work to estimate the contribution of Mexico to the global RF by its emissions of CO2 (the most significant of the AGG), CH4 and N2O during the period 1990-2011, which are reported in the Inventario Nacional de Emisiones de Gases de Efecto Invernadero (National Inventory of Greenhouse Gases Emissions, INEGEI) (INECC, 2013). In comparison, by 2010 the national emissions per capita of Argentina, Spain and the United States were 108.8, 110.8 and 327.0% of the Mexican emissions, respectively, in units of equivalent CO2. Mexico’s CO2 emissions retained in the atmosphere during 1990-2011 amount to 4 624 457 Gg; they are higher than those of Spain and Argentina together, and represent 1/12 of the USA contribution. Mexico’s contribution is 1.47% of the global RF due to CO2, with a similar proportion than Spain and Argentina, but a smaller fraction compared to that of the USA (1/15). The main uncertainties of our computations for Mexico’s contribution to the global RF come from national emissions; the INEGEI indicates that the emissions considered for the calculation of uncertainties represent 89% of the total emissions of the inventory, resulting in a total uncertainty of ±5.6%. We are aware that, as a consequence, the concentration increase of CH4 and N2O due to Mexico’s emissions retained in the atmosphere during 1990-2011 is lower than their respective uncertainties for global concentrations: 1.72 vs. 2 ppbv and 0.13 vs. 1 ppbv.

Keywords

Anthropogenic greenhouse gases, global radiative forcing, contribution of Mexico.

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