The world's biggest risks

Beware: Wild cards to watch for in 2015

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On top of the threat of the U.S. Federal Reserve tightening the screws, the risk of another recession in Europe and a stumbling recovery in Japan, there are a deck of "wild cards" that could trip up the global economy in the coming year, experts warned at the World Economic Forum (WEF) in Tianjin, China.

CNBC shuffles through the pack to see what the world should look out for in 2015.

Global pandemic

A major, under-appreciated risk to the world economy is infectious diseases, says Victor Chu, chairman of Hong Kong based private equity firm First Eastern Investment Group.

"We're not prepared for another major outbreak of Ebola, SARS or another infectious disease," Chu told CNBC on the sidelines of WEF in Tianjin, China.

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"We need a new global governance structure to allow more experimental drugs to be distributed a lot more quickly than existing arrangements because you don't know what's next. Ebola is scary, but the next variation will be scarier," he added.

Ebola – which was declared an international public health emergency early last month – is already having a serious economic impact on the economies of Guinea, Liberia and Sierra Leone in West Africa, where the outbreak is occurring.

The closure of borders and suspension of flights has begun to hinder trade flows in the region, while tourism is also taking a severe hit.

Russia Deputy PM: It's up to Ukraine to solve crisis

Sanction tensions

Russian Deputy Prime Minister Arkady Dvorkovich also cited deadly diseases as a potential threat to the world economy, but added that a potential escalation of sanctions on the back of the Ukraine crisis also poses a risk.

"These are couple of things that could turn out to be bad next year, epidemic diseases that could again switch off trade and the movement of people. Or something related to the Ukrainian crisis, like a new round of sanctions may be bring an extra negative to the world economy," he said.

Concerns around a trade war between Russia, which has been hit with successive sanctions since the crisis in Ukraine erupted back in March, and the West have intensified. In retaliation to its penalties, Moscow recently slapped import bans on a range of European and American agricultural and food products last month and threatened possible sanctions on aerospace, shipbuilding and auto sectors.

Read MoreRussia Deputy PM: 'Sanctions not good from any side'

China is more imbalanced than ever: Professor

China crisis?

Kenneth Rogoff, Professor of Economics and Public Policy at Harvard University named uncertainty around the outlook for China as a potential swing factor for the global economy .

"We are sitting in one of them," Rogoff said when asked what he thought a wild card risk for the global economy in 2015 was.

He added that if China did slow down "more dramatically than people expect, that would be very difficult. The slowdown would be a policy decision to try and slow things down that gets out of hand."

The slowdown of China's property market, fast growing corporate debt and rising non-performing loans in the banking sector have raised concerns about the country's financial stability.

Helping to quell some fears about the trajectory for the mainland economy, Chinese Premier Li Keqiang said during his opening plenary that structural reforms are improving the quality of the country's economic growth and helping reduce the risk of a hard landing.

Read MoreChina's reforms reducing hard landing risk: Premier Li

The demand's just not there…

International Monetary Fund Deputy Managing Director Zhu Min pointed to a lack of aggregate demand – or the total demand for final goods and services - in the global economy as a key threat.

"The lack of aggregate demand is the main concern, particularly in advanced economies. They are out of recession but growth is still moderate, so they need aggregate demand," said Zhu.

However, judging by its latest World Economic Outlook update published in July, the IMF expects relatively smooth sailing ahead. It expects the global economic output to grow 4.0 percent in 2015, up from an estimated 3.4 percent this year, helped by stronger growth in some advanced economies.

Staying on growth, Ashraf Salman, Egypt's Minister of Investment says what he fears most is that the recovery in the world economy falls off track next year.

"I'm worried about a slowdown in global GDP (gross domestic product) growth which will definitely have an impact of unemployment and cross trade business across the world," he said.

"I'm not sure how long the global economy can continue on a slow rate of GDP growth and high rate of unemployment," he added.