Changing weather and climate conditions worldwide – in combination with livelihood and food production systems, political trends, and human welfare – have affect patterns of human mobility and human population distribution. Research since the 1980s has inquired about the relationship between Earth´s changing environments and the movements of people – from voluntary and forced migration, displacement, on to relocation. As early as 1990, the Intergovernmental Panel on Climate Change (IPCC) warned that significant levels of human mobility could occur as a result of changing climatic conditions. Regions particularly sensitive to climatic stressors – whose societies often are very vulnerable to these and other stressors – include areas like low-lying islands and deltas, coastal zones, glacial-fed water systems and regions subject to persistent drought.