Environmental degradation and migration in Mexico

The January 2011 issue of Scientific American contains “Casualties of Climate Change” which takes an in-depth look at three case studies (Mozambique, Mekong Delta and Mexico) where (according to the authors) climate-forced migrations will be inevitable in the next 70 years.

The article combines research which formed part of the European Commission’s Environmental Change and Forced Migration Scenarios project (EACH-FOR), a global study on environmentally induced migration, with maps produced by the Center for International Earth Science Information Network (CIESIN) at Columbia’s Earth Institute.

In the case of Mexico, the case study suggests that the declining rainfalls and decreasing water availability resulting from climate change will lead to more frequent and more prolonged droughts, especially in central and western Mexico, alongside an increase in the frequency and severity of tropical storms and hurricanes. The authors cite evidence from interviews in the state of Tlaxcala that some climate-induced migration is already under way, as rainfall totals and timing have become less predictable.

Of course, predicting what the climate in Mexico (and elsewhere) will be like in 2080 is a decidedly risky undertaking. At best, such predictions are a statistical guesstimate. Even so, it is still useful to consider alternative climate change scenarios, together with their likely impacts on  environmental hazards and future movements of people. Looking at the alternatives may allow the development of strategies and policies which can reduce or minimize the adverse  social, human, economic and environmental impacts.

Four colorful maps accompany the Mexico case study:

• population density
• rain-fed agricultural land
• incidence of drought
• predicted change in runoff.

The downside: In some instances, data given in the text appears to conflict with the data shown on these maps. Furthermore, no definition for “drought” is offered in either the text or the relevant map. The drought map’s categories are stated to be “percent of growing season that experienced drought, 1988-2007) but some methodological clarification of the underlying assumptions made and how these figures were calculated would have greatly enhanced the map’s value.

Previous posts about climate change in Mexico:

• Expected impact on Mexico of global climate change
• The link between climate change and migration from Mexico to the USA
• Dust, snowmelt and the reduced flow of the Colorado River into Mexico