CLIMATE CHANGE, AGRICULTURE AND MIGRATION: EVIDENCE FROM BANGLADESH

2015 ◽  
Vol 06 (02) ◽  
pp. 1550006 ◽  
Author(s):  
KAZI IQBAL ◽  
PARITOSH K. ROY
Keyword(s):  
Climate Change ◽  
Standard Deviation ◽  
Behavioral Response ◽  
Climatic Variables ◽  
Income Shocks ◽  
Migration Rates ◽  
Livelihood Options ◽  
Level Data ◽  
Per Capita ◽  
And Migration

Changes in climatic variables influence households' decision regarding livelihood options and strategies to mitigate income shocks. Migration is one of the most frequently adopted coping strategies that affected people use. This paper studies how the changes in climatic variables such as temperature and rainfall impact migration through agriculture. Using district level data (64 districts) for three inter-census periods (1974–1980, 1981–1990 and 1991–2000), fixed effect (FE) and IV results show that uncertainty about changes in temperature and rainfall impacts migration through agricultural productivity. We found that a one standard deviation decrease in real per capita revenue increases net out-migration rates by 1.4% to 2.4%. The results suggest a predicted increase in rainfall uncertainty would increase net out-migration rates by 20% in 2030 relative to 1990, assuming that there will be no behavioral response from the farmers.

scholarly journals Understanding the Nexus of Climate Change and Migration: A Case of Dhye Peoples from Upper Mustang, Nepal

2019 ◽  
Vol 2 (1-2) ◽  
pp. 1-19
Author(s):  
Pragya Sherchan
Keyword(s):  
Climate Change ◽  
Water Availability ◽  
Land Suitability ◽  
Precipitation Trend ◽  
Suitability Analysis ◽  
Livestock Farming ◽  
Mass Migration ◽  
Livelihood Options ◽  
Underlying Causes ◽  
And Migration

People of Dhye village are recognized as the Nepal’s first climate refugees. Historical records show that mass migration of people from Dhye village has occurred for three times, with latest one attributed to the climate change. This article aims to explore and understand the underlying causes of the Dhye people’s migration, and to analyze the land suitability for their relocation. The article discusses that people of Dhye have migrated mainly to look for livelihood options, water availability and land for cultivation. As of now, more than two dozen water ponds have dried completely, and the only community reservoir serves as main source of irrigation water. This led to a decrease in cultivated area by one-fourth within last 40 years. The livestock farming has also been decreasing year by year with only one yak herder left in the entire Dhye village. The temperature trend is positive, whereas precipitation trend is negative. The land suitability analysis done by using Multi-Criteria Decision Analysis (MCDA) shows that Thangchung Chawale village is more suitable location than Dhye village in terms of cultivation area, water availability, and distance to health-post and transportation facilities.

scholarly journals Breathing space: deoxygenation of aquatic environments can drive differential ecological impacts across biological invasion stages

2021 ◽  
Author(s):  
James W. E. Dickey ◽  
Neil E. Coughlan ◽  
Jaimie T. A. Dick ◽  
Vincent Médoc ◽  
Monica McCard ◽  
...  
Keyword(s):  
Climate Change ◽  
Oxygen Saturation ◽  
Ecological Impacts ◽  
Neogobius Melanostomus ◽  
Aquatic Environments ◽  
Relative Impact ◽  
Low Oxygen ◽  
Per Capita ◽  
The Impact ◽  
Prey Populations

AbstractThe influence of climate change on the ecological impacts of invasive alien species (IAS) remains understudied, with deoxygenation of aquatic environments often-overlooked as a consequence of climate change. Here, we therefore assessed how oxygen saturation affects the ecological impact of a predatory invasive fish, the Ponto-Caspian round goby (Neogobius melanostomus), relative to a co-occurring endangered European native analogue, the bullhead (Cottus gobio) experiencing decline in the presence of the IAS. In individual trials and mesocosms, we assessed the effect of high, medium and low (90%, 60% and 30%) oxygen saturation on: (1) functional responses (FRs) of the IAS and native, i.e. per capita feeding rates; (2) the impact on prey populations exerted; and (3) how combined impacts of both fishes change over invasion stages (Pre-invasion, Arrival, Replacement, Proliferation). Both species showed Type II potentially destabilising FRs, but at low oxygen saturation, the invader had a significantly higher feeding rate than the native. Relative Impact Potential, combining fish per capita effects and population abundances, revealed that low oxygen saturation exacerbates the high relative impact of the invader. The Relative Total Impact Potential (RTIP), modelling both consumer species’ impacts on prey populations in a system, was consistently higher at low oxygen saturation and especially high during invader Proliferation. In the mesocosm experiment, low oxygen lowered RTIP where both species were present, but again the IAS retained high relative impact during Replacement and Proliferation stages at low oxygen. We also found evidence of multiple predator effects, principally antagonism. We highlight the threat posed to native communities by IAS alongside climate-related stressors, but note that solutions may be available to remedy hypoxia and potentially mitigate impacts across invasion stages.

scholarly journals Spatial and space-time correlations in systems of subpopulations with genetic drift and migration.

Genetics ◽  
1993 ◽  
Vol 133 (3) ◽  
pp. 711-727
Author(s):  
B K Epperson
Keyword(s):  
Population Genetics ◽  
Time Correlation ◽  
Space Time ◽  
Spatial Correlations ◽  
Gene Frequencies ◽  
Migration Patterns ◽  
Migration Rates ◽  
Space And Time ◽  
Time Correlations ◽  
And Migration

Abstract The geographic distribution of genetic variation is an important theoretical and experimental component of population genetics. Previous characterizations of genetic structure of populations have used measures of spatial variance and spatial correlations. Yet a full understanding of the causes and consequences of spatial structure requires complete characterization of the underlying space-time system. This paper examines important interactions between processes and spatial structure in systems of subpopulations with migration and drift, by analyzing correlations of gene frequencies over space and time. We develop methods for studying important features of the complete set of space-time correlations of gene frequencies for the first time in population genetics. These methods also provide a new alternative for studying the purely spatial correlations and the variance, for models with general spatial dimensionalities and migration patterns. These results are obtained by employing theorems, previously unused in population genetics, for space-time autoregressive (STAR) stochastic spatial time series. We include results on systems with subpopulation interactions that have time delay lags (temporal orders) greater than one. We use the space-time correlation structure to develop novel estimators for migration rates that are based on space-time data (samples collected over space and time) rather than on purely spatial data, for real systems. We examine the space-time and spatial correlations for some specific stepping stone migration models. One focus is on the effects of anisotropic migration rates. Partial space-time correlation coefficients can be used for identifying migration patterns. Using STAR models, the spatial, space-time, and partial space-time correlations together provide a framework with an unprecedented level of detail for characterizing, predicting and contrasting space-time theoretical distributions of gene frequencies, and for identifying features such as the pattern of migration and estimating migration rates in experimental studies of genetic variation over space and time.

scholarly journals A meta-analysis of the literature on climate change and migration

2021 ◽  
pp. 1-52
Author(s):  
Michel Beine ◽  
Lionel Jeusette
Keyword(s):  
Climate Change ◽  
Climatic Factors ◽  
Human Mobility ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Displacement Effect ◽  
Methodological Choices ◽  
Econometric Methods ◽  
And Migration

Abstract Recent surveys of the literature on climate change and migration emphasize the important diversity of outcomes and approaches of the empirical studies. In this paper, we conduct a meta-analysis in order to investigate the role of the methodological choices of these empirical studies in finding some particular results concerning the role of climatic factors as drivers of human mobility. We code 51 papers representative of the literature in terms of methodological approaches. This results in the coding of more than 85 variables capturing the methodology of the main dimensions of the analysis at the regression level. These dimensions include authors' reputation, type of mobility, measures of mobility, type of data, context of the study, econometric methods, and last but not least measures of the climatic factors. We look at the influence of these characteristics on the probability of finding any effect of climate change, a displacement effect, an increase in immobility, and evidence in favor of a direct vs. an indirect effect. Our results highlight the role of some important methodological choices, such as the frequency of the data on mobility, the level of development, the measures of human mobility and of the climatic factors as well as the econometric methodology.

How Should We Talk About Climate Change and Migration?

2020 ◽  
Author(s):  
James Morrissey
Keyword(s):  
Climate Change ◽  
Human Migration ◽  
Policy Response ◽  
Limited Capacity ◽  
Flexible Approach ◽  
Single Term ◽  
And Migration

Abstract This paper is a response Ferris (2020), specifically to the call for coalescence around a single term by which to talk about people migrating in response to climate change. While sympathetic to the imperative behind Ferris’ (2020) call, my overall argument is to reject this proposal. Instead I argue for less of focus on what we call people migrating in response to climate change, and more of a focus on how we talk about them. To justify this, I argue that a single term is inherently reductive and likely to play upon anti-immigrant sentiment due to the need to portray ‘migration as a problem’. At best this will result in a policy focus with limited capacity to address the challenge of migration in a context of climate change. At worst it will drive a policy response that is overtly counter-productive. As an alternative, I propose embracing a multitude of discourses, informed by principals that I argue will drive a humane climate agenda, and allow for a flexible approach that can account for the variety of concerns at the nexus of climate change and human migration.

China’s Fairness Discourses and Allocation of Climate Responsibility

2021 ◽  
Vol 5 (1) ◽  
pp. 63-95
Author(s):  
Feiyue Li
Keyword(s):  
Climate Change ◽  
Legal System ◽  
Fair Allocation ◽  
Active Engagement ◽  
Global Response ◽  
Climate Change Negotiations ◽  
The World ◽  
International Climate ◽  
International Legal System ◽  
Per Capita

Abstract The idea of ‘fairness’ may be viewed as fundamental to a nation’s participation in the development of the international legal system governing climate change. As the second-largest economy and the largest Greenhouse Gas (GHG) emitter in the world, China’s actions on climate change are critical to the global response. Indeed, international cooperation on climate change is unlikely to succeed without China’s active engagement. Therefore, China’s perception of the fairness of responsibility allocation will significantly influence its attitudes toward its international climate responsibilities. However, limited work has been done to date to concretely examine China’s perspective of the fairness of responsibility allocation and to understand its fairness discourses and practices of climate responsibility in a dynamically evolved process. This article aims to fill that gap in the literature by elucidating how China perceives the fair allocation of climate responsibility and how its fairness discourses and practices have evolved over the course of the three phases of international climate change negotiations. It will be shown that China has perceived the factors of historically accumulated emissions, per capita emissions and capability to lie at the very core of its understanding of fairness.

Estimating Effective Population Size and Migration Rates From Genetic Samples Over Space and Time

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 429-446 ◽  
Author(s):  
Jinliang Wang ◽  
Michael C Whitlock
Keyword(s):  
Population Size ◽  
Effective Population Size ◽  
Joint Estimation ◽  
Large Sample Size ◽  
Effective Population ◽  
Likelihood Methods ◽  
Marker Allele ◽  
Migration Rates ◽  
Space And Time ◽  
And Migration

Abstract In the past, moment and likelihood methods have been developed to estimate the effective population size (Ne) on the basis of the observed changes of marker allele frequencies over time, and these have been applied to a large variety of species and populations. Such methods invariably make the critical assumption of a single isolated population receiving no immigrants over the study interval. For most populations in the real world, however, migration is not negligible and can substantially bias estimates of Ne if it is not accounted for. Here we extend previous moment and maximum-likelihood methods to allow the joint estimation of Ne and migration rate (m) using genetic samples over space and time. It is shown that, compared to genetic drift acting alone, migration results in changes in allele frequency that are greater in the short term and smaller in the long term, leading to under- and overestimation of Ne, respectively, if it is ignored. Extensive simulations are run to evaluate the newly developed moment and likelihood methods, which yield generally satisfactory estimates of both Ne and m for populations with widely different effective sizes and migration rates and patterns, given a reasonably large sample size and number of markers.

Sign in / Sign up

Export Citation Format

Share Document