Currencies are soaring in the parts of the world that helped the global economy recover. Will they now become what hampers it?

At a time when the world's advanced economies stumble over huge debts and deficits, developing nations have been thriving. Emerging economies, especially around Asia, have led the global economic recovery by selling more goods and services abroad and by benefiting from the rebound in prices for everything from copper to coal and other commodities.

In 2010, global GDP leaped to 5% after contracting by 0.6% the previous year, according to the International Monetary Fund. Developing Asia -- from Thailand to China to India -- contributed to the bulk of this growth, growing 9.3%, compared with advanced economies from Japan to the U.S. to Europe growing only at a nimble 3%. Even at the height of the global financial crisis in 2009, developing Asia saw robust 7% growth, while GDP in the advanced world contracted by 3.4%.

When it comes to forecasting, these economies have been a much easier read for economists and investors compared to, say, Europe, as the region's debt crisis has taken hold of Greece and Ireland and potentially Spain, Portugal, Italy and Belgium.

But for 2011, prospects in developing Asia are much murkier, thanks in part to the rise of their currencies, from the Thai baht to the Malaysian ringgit. Experts say it's one of the wild cards that could potentially hamper global growth. Stronger currencies, especially in developing Asia where growth is largely driven by exports, make selling goods and services abroad relatively more expensive.

The baht rose by about 11% in 2010 – the second-strongest Asian currency after the Japanese yen. And so far this year, the ringgit has strengthened 0.4%, the most among Southeast Asian currencies. More