Key Facts

- Speaking at a conference in Norway, Musk claimed "civilization will crumble" if the world halted the use of oil and natural gas and called for continued drilling and exploration of fossil fuel sources, Reuters reported.

- The billionaire suggested that the transition to green energy sources will take decades and that fossil fuels will be needed in the meantime.

- Last week, Musk—who has previously evangelized renewable energy sources—called for increased nuclear power generation and attacked environmentalists who oppose nuclear plants as "anti-human."