So says the IPCC in a new report. They estimate that the apportion of renewable energy sources will increase anyhow but that it will be a lot faster if there is a concerted political effort.
An optimistic projection has 77% of World's energy demand coming from renewable sources by 2050. Today it is only 13%.
In 2009 the fastest growing renewable was solar-photovoltaic (up 50% in just one year), followed by wind (+30%) and solar-thermal (+20%), ethanol and biodiesel (+9-10%) and finally the quite exhausted hydroelectric (+3%).