The mood was glum as the World Economic Forum's annual meeting of academics and leaders from business and politics kicked off Wednesday in Davos, Switzerland, with worries ranging from energy to geopolitics and China's slowdown causing widespread unease.

Problems such as the refugee crisis in Europe, the ultralow oil price and the challenges of new technology have overshadowed the global economic outlook this year, a tone that is reflected in this summit so far.

The four-day meeting in the resort town drew more than 2,500 representatives from business, politics, academia and NGOs from more than 100 countries.