In what has felt a bit this year like a headlong rush toward zero-emission battery-electric and hydrogen-fuel-cell vehicles, are we overlooking other potential environmental impacts?

Regulators in California and 15 other states are pushing a transition to zero-emission vehicles. OEMs, component makers, and others are pouring money into research and development. Yet many questions must be addressed before they can be widely adopted commercially. There are those that deal with vehicle operations, such as range, weight, charging/fueling infrastructure, and cost. But there are larger questions that need to be addressed, such as electric grid capacity, the availability of raw materials to make batteries, scaling up hydrogen production, and battery disposal.

In some areas of the country, electricity still comes largely from plants powered by fossil fuels such as coal and natural gas. We could be trading tailpipe emissions for smokestack emissions.

On the West Coast, much of the electricity is produced via zero-emissions methods, such as solar, wind, and hydro-electric. Yet all these technologies raise their own environmental concerns outside of emissions.

For instance, environmentalists have criticized large solar farms for their impact on protected animal and endangered plant species. They advocate the use of Distributed Energy Resources instead — microgrids connecting systems of photovoltaic panels across rooftops, parking lot shade structures, and commercial buildings such as warehouses and distribution centers.

The Department of Energy points out that while hydropower generators do not directly emit air pollutants, dams, reservoirs, and the operation of hydroelectric generators can affect the environment, obstructing fish migration, as well as changing natural water characteristics and affecting the plants and animals in and around the river.

Overall, the DOE says, using wind to produce energy has fewer effects on the environment than many other energy sources. But some types of wind turbines and wind projects cause bird and bat deaths — and not everyone wants a view of a wind farm.

So what about hydrogen? Producing hydrogen in itself takes electricity, so it raises all the same questions.

In addition, hydrogen production from steam methane reforming, the most common process, currently releases CO2 into the air. Hydrogen-producing facilities will need to capture that and re-use it to make fuel-cell vehicles more environmentally friendly. Truly getting to “green” hydrogen will take a different process, using the energy from renewable energy to split water into hydrogen and oxygen and capture that hydrogen. 

There are also wider environmental and social concerns around the raw materials used in batteries. For example, two-thirds of all cobalt production happens in the Democratic Republic of the Congo, according to the UN, and about 20% of that comes from artisanal mines where up to 40,000 children work in dangerous conditions for meager income.

And in Chile, lithium mining uses nearly 65% of the water in the country’s Salar de Atamaca desert region to pump out brines from drilled wells. This has forced quinoa farmers and llama herders to migrate and has caused soil contamination, groundwater depletion, and pollution, according to the UN.

The industry is researching the possibility of using other materials, but like the transition to green hydrogen, that’s going to take time.

And then there’s the question of what happens to electric-vehicle batteries once they’re depleted. A UK study published a year ago in the scientific journal Nature said governments and industry need to act now to develop a robust recycling infrastructure. Not only will that keep toxic batteries out of landfills, it would allow re-use of the cobalt and lithium.

All this is not to say that we shouldn’t be working toward zero-emission vehicles, especially in areas of the country like Southern California where air pollution is still a major problem. But if you look at a broader definition of green, environmentally friendly, and sustainable, it’s a much more complex issue than what comes out the exhaust stack.