Shell's Chief Executive quoted Tuesday that the world will remain severely dependent on fossil fuels for the next 40 years, following massive US oil spill cast a cloud over the industry.

"Energy demand will double between now and 2050. We have currently roughly 80 percent of fossil resources delivering the energy demand today. We still see this at around 60 percent by 2050", said the Chief Executive of the Anglo-Dutch energy giant.

It is believed that fossil fuels, including oil, natural gas and coal, will continue to pose as a dominant source for fulfilling surging world energy demand until at least 2050, despite of the presence of new alternative sources.

Voser, during the opening of a petrochemical complex in Singapore, quoted that alternative and renewable energy sources will only grab nearly 30 to 40 percent of market share within the same time period.

He added that extending alternative energy sources time to become efficient and economically viable will, in the future, assist in fighting against any adverse environmental disaster by the use of fossil fuels.

At least 210,000 gallons of crude a day has been streaming from a well below the Deepwater Horizon rig that sank on April 22, after a massive explosion that killed 11 workers.