IEA chief Nobuo Tanaka delivered the keynote address at an energy conference arranged by the European Investment Bank in Thessaloniki, Greece.
Tanaka said the 2009 energy outlook by the IEA predicted world energy consumption would rise 1.5 percent each year through 2030. Fossil fuels, he said, will meet up to 75 percent of this demand.
Europe is scrambling to diversify its transit options. Conflict between Russian and Georgia in 2008 disrupted oil supplies through a major pipeline. A 2009 dispute between Kiev and Moscow left European consumers without gas for weeks.
"So in short, the energy security and climate change challenges require balanced and sustainable energy policies not just at home but also beyond our borders," said Tanaka.
He advocated a policy that encouraged energy efficiency and transit diversity through a series of hydrocarbon networks in southern Europe. This includes liquefied natural gas facilities and the Nabucco gas pipeline.
Tanaka said the business-as-usual model would damage the environment and undermine energy security for Europe.
"This energy future is not sustainable economically, environmentally and socially," he warned.