Over coming years, migration flows related to climate change are expected to increase, particularly in the world’s poorest countries. This is because climate change is expected to increase the frequency and
severity of extreme environmental events, such as drought, sea level rise, floods and hurricanes. The links between environmental changes and migration are extremely complex. Migration is often the result of a variety of layered causes – economic, social and political – which are accentuated by changing environmental
conditions as well as frequently by developmental and demographic conditions.
The patterns of movement of environmental migrants can also vary – these may be internal within a country or international; voluntary or forced; temporary or permanent. Forced migration might result from an environmental catastrophe such as a tsunami or flood, or a government-instigated relocation, while more
gradual process of migration could be caused by slow onset environmental deterioration, such as the long-term effects of drought on agriculture experienced in parts of Morocco, Algeria, Tunisia, Somalia and Egypt.
Although not all related to climate change, extreme weather events in 2010 affected over 320 million people – the highest number this century – according to the 2013 World Disasters report from the International
Federation of Red Cross and Red Crescent Societies (IFRC).