If the global economy spirals downward as some think it could, workers are likely to take it on the chin. And if that happens, it’s a fair bet that support for globalization will erode.

A new report from the International Labour Office finds that economic turbulence—largely due to credit market turmoil and rising oil prices—could spur an increase in global unemployment by an estimated 5 million people in 2008.

The number of unemployed people worldwide in 2007 was an estimated 189.9 million, and the global unemployment rate was 6 percent, says the ILO, an agency of the United Nations.

Not only does the ILO’s annual Global Employment Trends report warn of a gloomy 2008, it has some bad news from 2007. Despite “sound” global economic growth of 5.2 percent and a net increase of 45 million new jobs last year, not all was sweetness and light for workers around the world, according to the study. It said the global unemployment rate was virtually unchanged, and the worldwide deficit in decent jobs—especially for the poor—is “massive.”

An estimated 487 million workers, or 16.4 percent of all workers, still don’t earn enough to lift themselves and their families above the $1 per person, per day poverty line. Meanwhile, 1.3 billion workers—43.5 percent—still live below the $2 per day threshold, the ILO says.

“While global growth is annually producing millions of new jobs, unemployment remains unacceptably high and may go to levels not seen before this year,” ILO director-general Juan Somavia said in a statement.

For business leaders, the prospect of millions more workers unemployed around the world this year should do more than tug at the heartstrings. Those workers double as consumers who may lose purchasing power, and as citizens who may turn against the global trade system.

That interconnected system is generating prosperity and profits in many places. But it also can amount to a tight-wire act for workers—one in which the safety net leaves much to be desired.

Unemployment benefits have been falling in the group of mostly developed countries that make up the Organization for Economic Cooperation and Development. A report last month from the research organization found that across most OECD countries, the level of benefits that unemployed people typically receive was 59 percent of average after-tax earnings in 2001. That figure fell to 55 percent in 2005. The report found that the “index of generosity” in the U.S., Greece, Turkey and Italy is below 30 percent.

Already, support for global trade is waning in some quarters. Americans and Western Europeans are less supportive of international trade and multinational companies than they were five years ago, according to a study last year by the Pew Research Center.

Political leaders in the U.S. are working on an economic stimulus package that may temporarily extend unemployment benefits. Will these leaders and others around the world do enough to head off or ease the potential trouble ahead?