A/HRC/25/48 social support, coping mechanisms and protective environment a community and familiar context provide. Children migrating on their own are easy prey for traffickers. While it holds numerous positive aspects, migration is also an important component of international mobility that facilitates the sale and sexual exploitation of children. 41. The number of migrants worldwide has increased rapidly in the past few years, reaching almost 1 billion persons — one in seven human beings. The number of international migrants in 2010, estimated at 214 million according to the Department of Economic and Social Affairs, could almost double by 2050, and internal migrants accounted for 740 million migrants in 2009, according to the United Nations Development Programme.21 Similarly, the number of people uprooted by conflict or persecution is at its highest level in 18 years.22 42. Children and young people represent an important proportion of the migrant population. It is estimated that there are 33 million international migrants under the age of 20, representing 16 per cent of the international migrant population, but over 20 per cent in Africa and Asia. One third of these migrants are adolescents, while 39 per cent are under the age of 10.23 Data on internal migration and children left behind is not available. However, global trends suggest that this issue will remain significant in the coming years. Conflicts and violence24 4. 43. The breakdown of families, communities and social and institutional structures during conflict and in its aftermath puts children at great risk of being sold, trafficked and sexually exploited. The World Development Report 2011 of the World Bank estimates that approximately 1.5 billion people live in countries affected by repeated cycles of political and criminal violence.25 The current nature of conflicts, mostly civil wars fought by armed groups rather than the military, disproportionately affects civilians. Children pay a high toll. A child living in a conflict-affected or fragile developing country is nearly three times more likely to be out of school than a child living in a developing country that is unaffected by these factors. Sexual and gender-based violence is a major issue, during and in the aftermath of conflict. Women and children account for close to 80 per cent of refugees and internally displaced persons. As more countries fall into conflict and high levels of political and criminal violence, involving an increasingly complex range of protagonists and ever more violent schemes, children will continue to be exposed to heightened risks. Climate change and natural disasters26 5. 44. Global warming and natural disasters have continued to affect children in all parts of the world. According to UNICEF, “climate-related hazards are increasing, accounting for 70 per cent of all disasters today compared to 50 per cent two decades ago, and such 21 22 23 24 25 26 10 See International Organization for Migration, World Migration Report 2011. Available from http://publications.iom.int/bookstore/free/WMR2011_English.pdf. United Nations, The Millennium Development Goals Report 2013. UNICEF, “International migration and generation 2025”, in Population Dynamics: International migration, children and adolescents, April 2013. Available from www.unicef.org/socialpolicy/files/Population_Dynamics_and_Migration%282%29.pdf. See http://childrenandarmedconflict.un.org/ and http://srsg.violenceagainstchildren.org/. http://web.worldbank.org/WBSITE/EXTERNAL/EXTDEC/EXTRESEARCH/EXTWDRS/0,,content MDK:23252415~pagePK:478093~piPK:477627~theSitePK:477624,00.html. See the report of the Special Rapporteur on the sale of children, child prostitution and child pornography on the protection of children from sale and sexual exploitation following humanitarian crisis due to natural disasters (A/HRC/19/63).