Migrants who have crossed borders in search of work and a better life could exceed 400 million, or nearly 7 per cent of the present global population, by 2050, said a report issued this week.

The report, by the Geneva-based International Organisation for Migration (IOM), said movement within countries is also climbing as people move into cities, and has taken the global migrant total to one billion this year.

\”Over the next few decades, international migration is likely to transform in scale, reach and complexity,\” said the report which is issued every two years by the IOM.

\”If the migrant population continues to increase at the same pace as the last 20 years, the stock of international migrants worldwide by 2050 could be as high as 405 million.\”

The IOM\’s U.S. director-general, William Lacy Swing, said governments must now develop long-term policies to ensure the trend benefits host nations as well as the migrants themselves.

The study said the world stock of migrants — those who have already migrated and settled in new countries — climbed from 191 million in 2005 to 214 million last year.

The report said the rise is inexorable and unavoidable in the face of changing global demographics with surging numbers of workers chasing too few jobs in developing economies and people fleeing the effects of climate change.

It said however the response of governments, although spending vast sums annually to strengthen their ability to manage the trend, is often short-term, piecemeal and fragmented.

\”The risk of not putting in place policies and adequate resources to deal with migration is to lose an historic opportunity to take advantage of this global phenomenon,\” Swing said.

\”Given the unrelenting pace of migration, the window of opportunity for states to turn the negatives of migration into positives is shrinking.\”

If there were no major investment in issues related to migrants — such as providing housing, education and health services — problems associated with their integration into host societies would become even more acute than they are now.

\”Investment and planning in the future of migration will help improve public perceptions of migrants, which have been particularly dented by the current economic downturn,\” said Swing.

\”It will also help to lessen political pressure on governments to devise short-term responses to migration.\”