Defining the meaning of “climate refugee” in legal terminology is complicated. (The International Organization for migration and the Office of High Commissioner for Refugees (UNHCR) prefers to avoid the use of the terms as their use may potentially underline the status of refugees.) The main reason for the impact of human-induced greenhouse gas emissions is extremely broad and might apply to the plight of many millions of refugees. It is hard to find an acceptable legal definition in international law since climate refugees are not formally protected in any Treaty. There are concerns that changing the current definition of “refugee” to include “climate refugee” would be too controversial and would have the unintended consequence of weakening the protection for refugees in general. While Paris COP21 did not make direct reference to climate refugees, it recommended setting up a task force to provide integrated strategies to minimize displacement relating to adverse climate change. Estimating the number of people around the world that have been forcibly displaced because of floods, windstorms, or droughts is challenging, as major natural disasters occur with some regularity and the number of refugees or displaced people varies yearly. Some move within their own country and others seek refuge abroad. The number of climate refugees appears to be rising but estimates are hard to establish. Even so, since 2008, the United Nation's Internal Displacement Monitoring Centre has monitored migration numbers on an annual basis and there are on average 26.4 million people displaced throughout the world because of extreme weather events. It is predicted that 200 million or more people will migrate because of climate change factors by 2050.
The Impacts of Climate Change, A Comprehensive Study of Physical, Biophysical, Social, and Political Issues, 2021, Pages 537-545,