Climate change could drive more than 200 million people from their homes over the next three decades, creating pockets of migration unless urgent action is taken, according to a World Bank report.

The measures, according to the institution, include the overall reduction of pollutant emissions and closing the gaps in development.

The second part of the Groundswell report, released today, analyzes how the slow impacts of climate change, such as water scarcity, reduced productivity, and rising sea levels, could lead to millions of "climate migrants" by 2050 under three different scenarios, depending on climate action and development.

In the most pessimistic scenario, with a high level of emissions and uneven development, the authors of the paper predict more than 216 million people will be displaced from their countries in six regions analyzed.

These regions are Latin America, North Africa, Sub-Saharan Africa, Eastern Europe and Central Asia, South Asia, and East Asia and the Pacific.

In the most favorable scenario, with low emissions and even sustainable development, the number of migrants may be 80% lower, but still cause the displacement of 44 million people.

The report does not analyze the short-term impacts of climate change, such as the effects on extreme weather events.

The findings "reaffirm the potential for climate to induce migration in countries," said Viviane Wei Chen Clement, senior climate change expert at the World Bank and one of the authors of the report.

In the worst case scenario, sub-Saharan Africa - the most vulnerable region due to desertification, fragile coastlines, and agriculture-dependent population - would see the largest movement, with more than 86 million climate migrants.

North Africa, however, may have the highest proportion of climate migrants, with 19 million people moving, equivalent to 9% of the total population, due primarily to increased water scarcity on the northeast coast of Tunisia, the northwest coast of Algeria, western and southern Morocco, and the central foothills of the Atlas, according to the report.

In South Asia, Bangladesh is particularly affected by floods and crop destruction, accounting for nearly half of the climate migrants, with 19.9 million people, including an increase in the percentage of women, moving by 2050 in the pessimistic scenario.

"This is our humanitarian reality right now and we are concerned that it is going to be even worse, where vulnerability is most acute," said Maarten van Aalst, director of the Red Cross International Climate Center, which was involved in the report.

The report did not focus on climate migrants at the borders.

"Globally we know that three out of four people who move stay in countries," pointed out Kanta Kumari Rigaud, a prominent environmental expert at the World Bank and coauthor of the report.

However, migration patterns from rural to urban areas often precede movements to the frontiers.

While the influence of climate change on migration is not new, it is often part of a combination of factors that push people to leave and acts as a multiple threat.

People affected by conflict and inequality are more vulnerable to climate change because they have limited means to adapt.

The authors of the report also warn that migration hotspots may emerge in the next decade and intensify by 2050.

Planning is needed on both sides, in the areas where people will move and in the areas they leave, to help those who stay.

Lusa Agency