Even under climate change pledges made under the Copenhagen Accord last year, fossil fuels will still account for over half the increase in total energy demand, with oil to remain the dominant fuel, the IEA said in its World Energy Outlook report.
It forecasts demand for oil to rise by 18 per cent between 2009 and 2035, driven by developing countries, with nearly half the increase due to China alone.
In addition, "the oil price needed to balance oil markets is set to rise," the IEA warned, saying it expected the price of crude oil to rise by 88 per cent.
Demand for natural gas should increase by 44 per cent to 4.5 trillion cubic metres.
The IEA concluded that this "rising demand for fossil fuels would continue to drive up energy-related carbon dioxide emissions through the projection period.
"Such a trend would make it all but impossible to achieve the two degree C goal..."
The Copenhagen Accord sets a non-binding target of a two degrees Celsius increase in the global average temperature from pre-industrial changes, a level scientists believe is needed in order to prevent the most damaging climate change.
The IEA said government commitments made at Copenhagen "fall short" of what is needed to get to the two degree C target, and the forecast increases in energy consumption would likely result in an increase of 3.5 degrees C.
In particular, the IEA noted that increasing demand would force oil companies to unconventional sources, such as oil sands and shale, which are not only costly and will drive up prices, but which generally emit more greenhouse gases.