IAM Meeting, NCAR, July 21-22, 2014 Situated ex situ adaptations: U.S. migration from rural Mexico as a response to climatic variability Fernando Riosmena Population Program and Geography Department University of Colorado at Boulder In collaboration with University of Colorado scholars Lori Hunter (Sociology), Raphael Nawrotzki (Sociology), Dan Runfola (POP/NCAR), Stefan Leyk (Geography), and Sheena Murray (Economics)
Climate change has implied increasing temperaturas in Northern, Arctic latitudes, (semi-)arid biomes Source: http://data.giss.nasa.gov/gistemp/
Under medium-high emissions scenario, precipitation also expected to (decrease) in (e.g., Mexico); more variability, extremes as well Nota: Cifras de verano, escenario A1B 2080-2099, JJA Source: NRC (2010)
Adaptation, coping responses to climate change, variability We have done some work to understand whether relative rainfall (deficits) are associated with (international) migration responses l (Useful for projections/forecasting) l Plenty of experts note that CC change will not create a large number of international environmental refugees l But what about countries with well-established international migrant networks? Migration, one of several possible responses l V i = f ( E i, S i,j, AC i,j,k,l ) l A sign of vulnerability and a show of adapative capacity in families, communities
Vulnerability, a function of Institutions, markets, networks New Economics of Labor Migration Social Capital Theory Definition Exposure Nature/degree of stress (magnitude, frequency, duration, areal extent) Sensitivity Degree to which system is directly or indirectly modified or affected by perturbation Adaptive capacity Entitlements/capitals: actual/potential resources available to individuals based on own production, assets, reciprocity Measures Role Environmental stressor (Relative) rainfall deficits ( climatic variability) Mediator/modulator of impact of environmental stressor Irrigation availability Total agricultural surface Mediator/modulator of response to stressor Local economic diversity Migrant networks Adaptations, coping actions (outcomes; ex post, ex ante) In situ Received food rations, requested loan, sold equipment, replanted field, sold livestock, alternative crops, activities (e.g., milk production) Ex situ Wage labor through mobility/ migration
Some highlights of our work 100.0 80.0 60.0 40.0 20.0 0.0-20.0-40.0-60.0-80.0 In Historical region Outside of Historical region -100.0 Drought in current year Drought in prior year Drought two years prior
Relationship is contingent on exposure (drier period, places) & sensitivity (Nawrotzki, Riosmena, & Hunter 2013) Results from analyses of 2000 Mexican Census long form using multilevel model (household, municipality, state) controlling for: - Household lifecycle, labor supply, SES - Municipality migrant networks, marginalization - State-level GDP growth Source: Nawrotzki, Riosmena, & Hunter (2013, Population Research and Policy Review) Probability that a HH sends an international migrant in 1995-1999 (%) Decrease in rainfall in 1994-1999 relative to 1988-1993 (%)
Relationship in times with higher rainfall, fairly contingent on adaptive capacity, i.e., networks (Riosmena et al., under review) Results from analyses of 2010 Mexican Census long form using multilevel model (household, municipality, state) controlling for: - Household lifecycle, labor supply, SES - Municipality migrant networks, marginalization, irrigated farmland - State-level GDP growth Source: Riosmena, Nawrotzki & Hunter (under review) Probability that a HH sends an international migrant in 2005-2009 (%) Change in rainfall in 2004-2009 relative to 1974-1993 (%)
Relationship in times with higher rainfall, fairly contingent on adaptive capacity, i.e., networks (Riosmena et al., under review) Results from analyses of 2010 Mexican Census long form using multilevel model (household, municipality, state) controlling for: - Household lifecycle, labor supply, SES - Municipality migrant networks, marginalization, irrigated farmland - State-level GDP growth Source: Riosmena, Nawrotzki & Hunter (under review) Probability that a HH sends an international migrant in 2005-2009 (%) Change in rainfall in 2004-2009 relative to 1974-1993 (%)
Relationships, robust to use of quasi-longitudinal data that allow us to control for period fixed effects Results from analyses of Mexican Migration Project data (66 communities) using multilevel model (household, municipality) controlling for: - Household lifecycle, labor supply, SES - Local migrant networks, municipal economic diversity - State- and time fixed effects Source: Hunter, Murray, and Riosmena (2013, IMR) Percent difference in odds of sending a migrant to U.S. (%) 100.0 80.0 60.0 40.0 20.0 0.0-20.0-40.0-60.0-80.0-100.0 *** * *** In Historical region Outside of Historical region **** p < 0.001 ** p < 0.01 * p < 0.05 p < 0.1 Drought in current year Drought in prior year Drought two years prior
Similar, but stronger, results when using satellite imagery-derived rainfall estimates Results from analyses of 2010 Mexican census data using Poisson regression modeling municipal (1) international and (2) internal migration (rates) controlling for: - Average household lifecycle, SES - Municipal migrant networks, total agricultural surface, irrigation availability Source: Runfola et al. (in progress) (mm/hour)
International migration is higher in municipalities with higher direct dependence on rainfall, with lower rainfall than expected Source: Runfola et al. (in progress)
Lower absolute precipitation also associated with higher emigration, but a small effect (Poisson regression on international and intermunicipal igration, 2010 Census) Source: Runfola et al. (in progress)
Discussion (implications for modeling and projections) Indeed, some international movement out of countries, places with wellestablished networks may be likely as a result of climate change However, highly situated relationship suggest incorporating social, economic, and migration history aspects to modeling and forecasting such movement More work is needed in our case to better understand role of sensitivity and adaptive capacity more precisely
Thanks! 100.0 80.0 60.0 40.0 20.0 0.0-20.0-40.0-60.0-80.0 In Historical region Outside of Historical region -100.0 Drought in current year Drought in prior year Drought two years prior
Source: Eakin (2005) Migrant networks as (transnational) forms of adaptive capacity (and thus flexibility, resourcefulness, resilience?)
Source: Smit and Wandel (2006: Fig. 1) But is migration truly a (translocal) adaptation, or a more simple, last-resort ex situ coping mechanism (for a few, in either case)?