"Not surprisingly, the G7 countries account for 78 percent of the increase, as their fiscal accounts have been hit hardest by the crisis," Jaime Reusche, associate analyst in Moody's sovereign risk group, said in the report.
Moody's said it expects global government debt to total 80 percent gross domestic product in 2010, up from a 10-year low of 63 percent in 2008.
Debt will also be less affordable, as measured in terms of interest payments relative to revenue, Reusche said.
For advanced industrial countries, interest payments are expected to total 6.1 percent of revenues in 2010, up from 4.3 percent in 2007.
"As growth turns negative in 2009 for most countries, the relative debt load becomes harder to bear," Moody's said.
In the United States, government debt is expected to rise to $14.48 trillion in 2010 from $12.29 trillion in 2009 and $10.27 trillion in 2008, the Moody's report said.
(Reporting by Dena Aubin) (