Earth day is coming up—as it has every year since 1970—and we have a new question for readers this year: When will buying gasoline cars seem weird?

Electric car advocates have been anticipating for years—decades, really—the day when plugging in will be more common than filling up.

Now that the United States has a broad selection of electric cars on the market, it looks like that day may be on the way.

So our poll asks, how soon do you think it will come? By 2025, which seems the earliest reasonable possibility? 2030? 2040? Or not until 2050 or later?

While electric cars initially saw sales ramp up more rapidly than hybrids, the adoption rate hasn't kept pace seven years on.

Plug-in car sales for 2017 amounted to barely 1 percent of overall car sales across the country.

Nissan Leaf electric car at EVgo DC fast-charging station

Nissan Leaf electric car at EVgo DC fast-charging station

Yet more people are noticing electric cars on the road, especially as Tesla's model selection widens, and its Supercharger network expands.

More people are likely to know someone or have a neighbor who drives an electric car.

Buyers now have a choice of SUVs as well as sedans and small cars, so it's becoming less weird to drive a car that plugs in.

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In the near term, if some political event shot gas prices skyward, more cities implemented bans on cars with tailpipes, or more countries implemented limits on carbon emissions, consumers could flock quickly to electric cars.

Given production announcements that automakers around the world have made, buying a plug-in car could be fairly common by 2025. 

On the other hand, if today's adoption rate of electric cars continues amid low gas prices, and if purchase incentives begin to expire, it could easily take until 2050 or later for internal combustion to become the exception rather than the rule.

Exhaust emissions from tailpipe [photo: Simone Ramella, 2005, used under Creative Commons 2.0]

Exhaust emissions from tailpipe [photo: Simone Ramella, 2005, used under Creative Commons 2.0]

Given our readers' proclivities, we have our suspicions about what participants will choose, but we'll save those for next week's report on the actual results. Vote now!

As always, please note that our Twitter polls are far from scientifically valid due to small sample size and self-selection by those who choose to participate.