Electric car charging point in Stoke on Trent, England.

Nathan Stirk | Getty Images News | Getty Images

The number of electric vehicles on the world’s roads is on the rise, beating last year’s record.

That sounds like good news as the world tries to break free from fossil fuels. But as electric cars become more and more popular, some are questioning whether they are environmentally friendly.

For example, batteries in electric vehicles charge directly from the grid – it is usually powered by fossil fuels. And there are questions about how energy-efficient it is to build an EV or EV battery compared to building a comparable traditional vehicle.

Are electric vehicles green?

The short answer is yes – but their full green potential is still many years away.

Experts generally agree that electric vehicles have a lower carbon footprint over their lifetime than traditional cars and trucks.

Last year, researchers at the Universities of Cambridge, Exeter and the University of Nijmegen in the Netherlands found that driving 95% of the world’s electric cars was more environmentally friendly than driving a gasoline car.

Most of the world’s electricity grids are still powered by fossil fuels such as coal or oil, and the EVs depend on that energy to power them. Separately, EV battery production remains a energy-intensive process.

The production of electric vehicles leads to higher emissions than the production of petrol cars … mostly from battery production.

Florian Noblock

Cambridge for Environment, Energy and Natural Resources Management

A study by the Massachusetts Institute of Energy Energy Initiative TV shows that EV’s battery and fuel production generate more emissions than car production. But those high environmental costs will be offset by the ever-increasing efficiency of EVs.

In short, for a battery-powered car, the total emission per mile is less than that of internal combustion engines.

“In some countries, electric vehicles are even better than the current grid,” said Sergi Paltev, a senior research scientist and co-author of the study at MIT Energy. .

Paltsv said the full benefits of EVs could only be realized after the power supply was renewed, and it could take decades.

Read more about electric vehicles from CNBC Pro

“The average electric vehicle in the United States today produces about 200 grams of CO2 per mile,” he said. By cleaning the grid, we can reduce emissions from electric vehicles by 75%, today from 200 (gram) to 50 grams of CO2 per mile by 2050.

Similarly, Paltsv’s MIT research currently shows 275 grams of CO2 per mile of unconnected hybrid vehicles. By 2050, their planned emission is expected to be between 160 and 205 grams of CO2 per mile – the region is much larger than the EVs, as fuel levels vary from place to place.

Decarbonation is the process of reducing greenhouse gas emissions from fossil fuels. Efforts to reduce pollution in various industries are expected to further reduce the environmental impact of EV production and charging.

Eric Hanon, based in Frankfurt, said: A partner at McKinsey & Company told CNBC.

Batteries are the biggest culprit

They rely on rechargeable lithium-ion batteries to make EVs work. Experts say that the process of producing those batteries — from the use of mineral raw materials such as cobalt and lithium, to power-based production in gigabyte factories and transport – is one of the largest sources of carbon emissions today.

Gigabit factories are the largest manufacturers of EV batteries.

“The production of electric vehicles leads to higher emissions than the production of petrol cars. Depending on the country of production, this is about 30% to 40% of production emissions, mostly from battery production, ”said Florian Nobblock Cambridge for Environment, Energy and Natural Resources Management.

Those high emissions figures are said to be “as fast as the initial investment, the lifetime emissions will pay off faster.”

China currently controls battery production, with 93 gigabyte-ion battery cells producing only four in the United States this year, the Washington Post reported.

“I think the battery is the most complex part of the AV, and it has a very complex supply chain,” George Crabtry, director of the U.S. Department of Energy’s energy storage research center, told NBC. Battery production makes a big difference to the carbon footprint for AVs.

Batteries made in older factories in China are often made from fossil fuels, as this was the trend five to 10 years ago, he said. Therefore, batteries built from batteries from existing factories are likely to have large carbon footprints.

But he says that is changing. “People are realizing that this is a big carbon footprint.”

Experts point to other issues related to battery production.

They include unethical and unsustainable mining, as well as complex geopolitical nature of the supply chain, where countries do not want to rely on raw materials such as cobalt and lithium or rechargeable batteries.

The raw materials needed for battery production (mining (decarbonate, etc.) may not be).

Reuse and disassemble the grid

Today, very few used batteries are reused.

Experts say that with the limited supply of raw materials needed for battery production, companies have no choice but to recycle it, which could change over time.

McKensey Hanoon lists other reasons why companies should redouble their efforts. They include a control area where manufacturers can withstand batteries used by law – and removing them can be more expensive.

Those who point to the lack of reusable infrastructure as a problem say that cars are so new that they do not realize that we do not need much more infrastructure.

Most car companies say they are working to ensure that EVs have significant potential on the site before the end of the next decade.

Climate change is not a silver bullet. Ideally, you should try to reduce the number of cars in bulk, and try to push things like public transportation

Florian Noblock

Cambridge for Environment, Energy and Natural Resources Management

He says much research from Nobbridge University at Cambridge is aimed at improving battery technology, making it more sustainable and less dependent on raw materials. He said more efforts are needed to deconstruct the electric grid.

“It is important to add more renewable energy to the grid each year than coal,” says Noblock.

“Compared to building a new fossil fuel station now, it’s much easier to build a big solar or sea wind. We’re seeing more renewable electricity coming into the grid around the world.”

However, he said, due to emissions from solar generators and wind turbines, generating electricity using renewable energy sources will still generate greenhouse gases. “We look at how long it takes for the electric grid to be decommissioned enough to make the most of electric vehicles,” Nobblock added.

Policies required for social change

Experts agree that the transition from petrol-powered cars to EVs is not a cure for global warming.

We need to go hand in hand with social change, which further encourages public transportation and alternative transportation, including cycling and walking.

Reducing the use of private vehicles requires a lot of financial and policy planning.

MET Palstsv, deputy director of the University’s Global Change Science and Policy Joint Program, said there are currently 1.2 billion cars on the road around the world, a figure expected to rise to 1.8 billion. 2 billion.

By comparison, there are currently only about 10 million electric vehicles.

“People underestimate how much new cars need to be produced and how much equipment is needed to produce those electric vehicles,” Paltev said.

The number of electric cars, buses, vans and trucks on the roads is expected to reach 145 million by 2030, according to the International Energy Agency.

Although everyone drives EVs more than gasoline cars, according to Noblock, there will be more emissions from plug-in vehicles.

“So it’s not a silver bullet for climate change mitigation. Ideally, you should try to reduce the number of cars en masse, and try to push things like public transportation. ” It is also important to exclude people from private transportation.