Almost 50% Loss in Production by 2080 in Mexico due to Climate Change

``The first three panels of Table 3 are based on scenarios and crop yield predictions made by Rosenzweig and Iglesias (38), all assuming an eventual stabilization level of atmospheric CO₂ concentration of 555 ppm, which, under the relatively conservative scenario B1 of the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (1), approximately corresponds to the year 2080 and represents global mean temperature increase of 1 °C to 3 °C above recent temperatures.The three panels use climate forecasts from different General Circulation Models (GCMs), including those of the Goddard Institute for Space Studies, the Geophysical Fluid Dynamics Laboratory (GFDL), and the United Kingdom Meteorological Office(UKMO). Although, in all cases, Mexico is expected to experience some reductions in crop yields as a result of climate change, the magnitude depends to a large extent on whether the fertilization effect of CO₂ is included and whether active agricultural adaptation measures are taken. On the one extreme with no CO₂ fertilization effect and no adaption, crop yields in Mexico are predicted to decline by at least 39% (GFDL), or as much as 48%(UKMO). In that case, the increase in Mexico’s emigration as a share of population (i.e., the fraction of all Mexican-born people living abroad) would be between 7.8% and 9.6%.Mexico’s population will differ in the future and the elasticity may change if the rural population fraction decreases further, and if the agricultural sector itself changes (i.e., results are sensitive to implicit assumptions about the path of development). Nevertheless, to indicate the broad scope of the phenomenon, we convert these percentages to absolute numbers of emigrants. Using today’s population of 70 million as the base for the age 15–65 y population in Mexico, this percentage increase corresponds to an additional 5.5 to 6.7 million emigrants.''

From Feng et al.