“With global economic prospects repeatedly marked down over the last five years, there is a concrete risk of a world economy persistently mired in sub-par growth, with unacceptably high levels of poverty and unemployment,” the IMF points out in a report before the G-20 leaders’ summit which will take place in Turkey on Sunday.

IMF economists highlight global gross domestic product (GDP) growth will reach 3.1% year-on-year in 2015 and 3.6%. The international body’s July forecasts had suggested economic expansion of 3.3% in 2015 and 3.8% in 2016.

“Growth remains fragile and could be derailed if transitions are not successfully navigated. In an environment of declining commodity prices, reduced capital flows to emerging markets, and higher financial market volatility, downside risks to the outlook remain elevated, particularly for emerging economies,” the IMF said.

The three biggest risks to the global economy are the upcoming normalization of monetary policy by the U.S. Federal Reserve, the slump in commodity prices and the slowdown in China.