The world's fossil fuel reserves cannot be burned unless some way is found to capture their carbon emissions, Royal Dutch Shell Chief Executive Officer Ben van Beurden said on Friday.

In an interview published in the Guardian newspaper, Van Beurden forecast that global energy use would produce "zero carbon" by the end of the century, and that his group would get a "very large segment" of its earnings from renewable power.

The interview came a day after Van Beurden slammed as a "red herring" calls to divest from energy companies as part of the fight against climate change, in particular the "Keep it in the Ground" campaign led by the Guardian.

"We cannot burn all the hydrocarbon resources we have on the planet in an unmitigated way and not expect to have a CO2 loading in the atmosphere that is often being linked to the 2C scenario," Van Beurden said. He was referring to studies that the climate could warm by 2 degrees centigrade or more by the end of the century if fossil fuels continue to be burned.

"I am absolutely convinced that without a policy that will really enable and realise CCS [carbon capture and storage] on a large scale, we are not going to be able to stay within that CO2 emission budget," he added.

Referring to the sometimes emotional opposition to Shell's decision to drill exploration wells this summer in the Alaskan Arctic, he said the decision was taken on rational grounds and that the technical risks had been assessed.

Environmental activists in Seattle have tried to hamper the Anglo-Dutch company's rigs from entering the port en route to the Chukchi Sea off Alaska, saying drilling in the remote Arctic waters could lead to an ecological catastrophe.