Elon Musk calls gas-powered cars a 'passing fad': 'They look cool in a museum.'

• Elon Musk says internal combustion engines will soon go the way of steam engines. 
• "They look cool in a musum," Tesla's CEO said of the traditional vehicle engines, calling them a "passing fad."
• Electric cars are slowly gaining steam, but gas-powered cars still make up a huge majority of the world's road transportation.
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Cars powered by internal combustion engines will soon only belong in museums, Elon Musk says.

The billionaire Tesla CEO tweeted Friday that the traditional vehicle power sources are merely a "passing fad" that will soon "look cool in a museum."

As the founder and chief executive of an electric car company, Musk has long been outspoken to the benefits of electric vehicles compared to carbon-spewing, fossil-fuel guzzling ones which make up a majority of the world's road transportation.

Adoption rates for electric cars continue to climb, though, with some 2.2 million registered in 2018. There are now roughly 5.6 million electric vehicles on the world's roads, according to the German nonprofit Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW). Tesla cars, notably, make up a majority of newly registered electric vehicles..

However, much of the world's energy produced to charge electric vehicles still relies heavily on traditional steam turbine engines. In the United States, only about 17% of electricity is generated by renewable sources, according to government statistics, with 63.5% coming from fossil fuels, most of which generate electricity by turning water into steam.

Pollution from power generation has fallen in recent years, however, with transportation now making up a greater share of carbon emissions in the United States, according to research from the University of Chicago.