in for example million people were displaced as a result of suddenonset climaterelated weather events compared to million internally displaced by conflict and violence there is however no global database on migratory movements related to natural disasters at best there are estimates that can be derived from displacement data relating to particular crises although the number of disasters has increased significantly over the last two decades see map showing the change in the number of natural disasters between and there has not been a major impact on international migratory flows as much displacement is shortlived and temporary and those who are displaced do not have the resources or networks to migrate abroad this is why it is often asserted that environmental change is likely to contribute to more internal rather than international migration for example environmental degradation may be the result of changes in average annual temperatures or rainfall levels but it may equally be the result of deforestation or poor land management or a combination of these factors