According to the United Nations High Commissioner for Refugees’ (UNHCR) annual Global Trends and accompanying Global Report, more than 1 percent of humanity were forced to flee their homes last year – the equivalent of one in every 97 people in the world. Of these displacements, 24.9 million were caused by disasters, including Cyclone Idai, one of the worst tropical cyclones on record to affect Africa and the Southern Hemisphere. This figure was three times the number caused by conflict and violence.

As the climate crisis worsens and with it the frequency of extreme weather events, its contribution to global displacement increases. In fact, this year for the first time the UNHCR’s annual report recognized climate change as a reason that caused refugees to flee.

“Major natural disasters, such as Cyclone Idai in Mozambique and neighbouring countries, and slow-onset climate change drove significant internal displacement,” the Global Report stated.

“Climate change contributed to worse, and more frequent, seasonal droughts and flooding, with resulting internal displacement in countries such as Afghanistan, Ethiopia, South Sudan, and Yemen,” it continued.

Matthew Saltmarsh, a global spokesperson for UNHCR, expressed the agency’s concern about the risk of the climate-related displacement of people.

“The impacts of climate change are unevenly weighted against the world’s most vulnerable people – those who are the poorest, most exposed, and have the least resources to withstand climate shocks and stresses,” Saltmarsh told IFLScience. “As the direct and indirect impacts of climate change exacerbate environmental, economic, and social vulnerabilities, many refugees and displaced persons originate from regions that are highly impacted by climate. At the same time, developing regions that are among those most climate-vulnerable host 85 percent of the world’s refugees."

This latter point could lead to further displacement of refugees, as the report explained.                           

“People of concern to UNHCR are on the frontlines of climate change, with refugees and IDPs [internally displaced people] often hosted in “climate hotspots” where they are exposed to the risk of secondary or multiple displacement due to disasters linked to natural hazards and the effects of climate change,” the Global Report said. “Furthermore, the impacts of climate change on certain regions may also hamper, or even rule out, possibilities for voluntary return.”

This final point brings into question the labeling of “climate refugees”. According to the 1951 Refugee Convention, a refugee is “someone who is unable or unwilling to return to their country of origin owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group, or political opinion.”

"While the term ‘climate refugee’ is sometimes used to categorize some or all of the various types of climate-related movements, in reality, it has no legal basis," Saltmarsh told IFLScience. 

"When people are displaced solely by the effects of climate-related disasters and hazards and cross international borders, they do not generally become refugees under the 1951 Refugee Convention."

There are several arguments for the use of the alternative term "climate migrants", to describe people who are displaced by climate change, but as the report suggests return may not be possible if the climate crisis continues.

"With climate change amplifying the frequency and intensity of sudden disasters (such as hurricanes, floods, and tornados), we are seeing a rise in forced displacement as a result," Saltmarsh said. "In recent years, according to the Internal Displacement Monitoring Centre, millions of people were forced to flee within their own countries due to disasters and weather-related hazards, including storms, cyclones, floods, droughts, wildfires, and landslides."

"Climate change is also contributing to more gradual environmental phenomena such as drought, desertification, and rising sea levels," Saltmarsh continued, "which can make land uninhabitable and will drive displacement over time. These longer-term impacts of climate change will have major consequences on people, cities and communities."

A report by the World Bank last year predicted that there could be 140 million “climate refugees" by 2050 unless “concrete” action is taken. A worsening climate crisis will continue to exacerbate the refugee crisis until world governments do better.