TOKYO – Toyota Motor Corp. has come under fire for what critics call foot-dragging on pure electric vehicles. Now the world’s biggest automaker is fighting back with its most robust retort.

Its message to those who say EVs are the only way forward in the global battle to cap carbon dioxide emissions: Science says you’re wrong.

Toyota is rolling out new facts and figures to back its strategy of taking a multipronged approach, blending EVs with hybrids and other green technologies.

Toyota insists new data shows that EV-only strategies, all the rage in some corners, fall short.

Toyota’s Chief Scientist Gill Pratt made that pitch in a presentation at the World Economic Forum in Davos this month. More recently, he repeated the message from Tokyo.

“Time will show that our point of view is actually the correct one,” Pratt said at a roundtable here. “One way or the other, there will be a diversity of powertrains used throughout the world.”

The question matters as more automakers plan to ditch internal combustion and go 100 percent EV as their path to carbon neutrality. Honda, including Acura, has joined Cadillac, Ford of Europe, Jaguar, Mini and Volvo in declaring intentions to sell only electric vehicles. Others, including Volkswagen, Ford and General Motors are diving aggressively into EVs.

By contrast, Toyota and other automakers, including the Hyundai Motor Group, back a more balanced approach. Toyota, for example, plans to sell some 5.5 million standard and plug-in hybrids a year in 2030 — more than double last year’s global total of 2.6 million.

But Toyota is hardly anti-EV.

The automaker is pouring tens of billions of dollars into EVs and expects to sell 3.5 million of them in 2030, including 1 million from the Lexus premium brand. And Lexus aims to sell only full-electric vehicles globally by 2035.

Despite this commitment, Toyota — the early pioneer in eco-vehicles with its breakthrough Prius hybrid — is increasingly criticized by some investors, environmentalists and EV enthusiasts who say President Akio Toyoda has moved too slowly into the quickly growing segment.

Pratt, a lanky MIT-educated robotics and artificial intelligence whiz, is also the CEO of the Toyota Research Institute, the carmaker’s U.S.-based skunkworks for futuristic technologies. Crunching the numbers on various paths to carbon neutrality was one of his latest brain teasers.

What Pratt’s team unveiled was a looming supply shortage for lithium, the critical ingredient in the lithium ion batteries needed for pure EVs, plug-in hybrids and standard hybrids.

This shortage will make it very difficult to supply all the EVs the industry envisions.

Toyota’s conclusion is that, to make the biggest dent in carbon emissions, it makes more sense to spread this limited supply of lithium among as many cars as possible to electrify as many cars as possible.

Pratt’s reasoning is that each car would have only enough lithium for a small hybrid battery, not the big, powerful batteries of a full electric. But because so many cars would be hybridized, their overall impact in reducing carbon dioxide emissions would be bigger than a smaller fleet of pure EVs.

Pratt likened today’s enthusiasm for EVs to yesterday’s confidence in autonomous driving: It’s overly optimistic, he said, citing Amara’s Law, a maxim claiming humans “overestimate the effect of a technology in the short run and underestimate the effect in the long run.”

Lithium shortages and a lack of recharging infrastructure will create an inevitable bottleneck that will kneecap big-volume rollouts of pure-electric vehicles over the next decade, he said.

“There is a crunch that’s going to come,” Pratt said. “Time is on our side. These shortages — not only of battery materials, but of charging infrastructure — will make it abundantly clear that one size does not fit all, and that the best answer is actually a mix of different vehicle types.”

Pratt’s model starts by hypothesizing a fleet of 100 traditional internal combustion vehicles, with average emissions of 250 grams of carbon dioxide per kilometer traveled.

Next, assume a limited amount of lithium, enough to make 100 kilowatt-hours of batteries.

If that lithium were used for a single 100 kwh battery, it could support one pure electric on the order of a top-grade Tesla. In that case, the fleet of 100 would have one EV and 99 traditional gasoline-burning vehicles, and its average fleet emissions would drop to 248.5 g/km.

But if that limited supply of lithium were spread among enough 1.1 kwh batteries, it would yield 90 traditional hybrids. The fleet would have 90 hybrids and 10 traditional combustion cars.

In that scenario, the average fleet emissions plunges to 205 g/km.

Counterintuitively, a big fleet of hybrids delivers a bigger blow against carbon dioxide than a smaller fleet of EVs, even though the hybrids are still equipped with gasoline-burning engines.

This nuance is lost in talk about legislating EVs on the road to carbon neutrality, Toyotasaid.

“If you look at the pledges that have been made by many different companies, usually they have a little asterisk [where they say] ‘We will hit this target by this year,’ ” Pratt said. “The asterisk says, ‘if conditions permit.’ ”

Pratt criticized such waffling ambitions as happy talk.

“What has to change is that we have to mature a little bit, and we have to stop doing wishful thinking,” he said. “A real discussion is that these are the constraints in the development of resources in the world, both material resources and charging infrastructure and renewable power… If that is true, how do we reduce the total amount of carbon dioxide that will accumulate?

“That is a mature discussion, not a kind of dream discussion.”

Toyota draws from several forecasts that show battery demand for lithium continuing to outstrip supply of lithium as far into the future as 2040. One scenario shows supply covering as little as one-third of total global demand in that time frame.

The reason is that it takes only two or three years to open a new battery factory, but up to 16 years to dig a new mine. “There’s going to be a delay in getting all the mining set up,” Pratt said.

The pinch isn’t limited to lithium.

Industry research shows a host of other metals needed for batteries are also falling into short supply, including nickel and manganese, Pratt said. Aside from crimping the supply of EVs, these material shortages will also likely push up battery costs. And higher sticker prices, in turn, will likely tamp down consumer demand for EVs, he predicted.

“We somehow have to lower carbon dioxide emissions as much as possible, as soon as possible, even though there is a tremendous shortage,” Pratt said, “and we’ll continue to have a tremendous shortage in battery materials. As you can imagine, it’s a big challenge.”

Pratt said he was inspired to delve into the battery question by his family’s experience owning a Tesla Model X. The vehicle has an impressive 300-mile range. But his wife typically drives it less than 30 miles a day. That means 90 percent of the lithium ion battery is dead weight, he noted.

“It’s an incredible waste of materials,” Toyota’s chief scientist said.

“I think what’s needed is a little bit more frankness from the OEMs, both to the public and also to policy makers.”