Electric vehicles are coming, but no one is sure how fast

A new study helps to show that experts are all over the map when it comes to gaming out the rise of electric vehicles in the global marketplace.

Why it matters: The speed at which EVs become truly mainstream is one variable affecting the future of oil demand and carbon emissions. Passenger cars account for roughly a fourth of world oil demand.

What they did: Columbia's Center on Global Energy Policy surveyed a suite of long-term forecasts from energy companies, government bodies, think tanks and others.

• The study compiled various analysts’ projections on several metrics, including the EVs share of global vehicle sales, the share of vehicle miles traveled, and EVs market share of the total fleet.

What they found: The latest round of analyses are slightly less optimistic than last year's projections for several reasons, including weakening U.S. policy and slightly slower projections of battery cost declines.

• The study also shows lots of divergences.
• "By 2040, the range of EVs’ market share is from 15 percent at the bottom to over 90 percent for the low carbon scenarios," writes CGEP's Marianne Kah.
• "Thus, there is no agreement on whether EVs will be a niche car or whether they will dominate vehicle sales by 2040."

Of note: Those super-high penetration rates in the chart above are based on various low carbon scenarios.

• They typically assume implementation of strong policies that would enable steep emissions cuts, as opposed to analysts' best guesses of what's most likely to unfold.

Go deeper: How the world's cities will drive electric vehicle adoption