When it comes to making cars friendlier to the environment, emissions are only part of the equation. The materials and production processes used must be considered as well. So Volvo's electric Polestar brand is looking to use more sustainable materials in future models.

The all-electric Polestar 2 has a vegan interior, but the brand said it plans to go further with future models, introducing natural and recycled materials to reduce plastic content, cut waste, and even reduce weight.

Polestar is experimenting with a natural-fiber based material from a company called Bcomp. The material is made from flax, which can be sustainably grown, according to Polestar. Flax is ideal for crop rotation programs and does not compete with food crops, the automaker said.

Used in car interiors the natural material could reduce plastic content by 80%, as well as reduce weight by 50%, over traditional components, according to Polestar.

Polestar is also considering use a "3D-knit" material, so named because a single thread can be used to make three-dimensional shapes. Already used in the fashion industry, the material is a yarn made from recycled PET plastic bottles, according to Polestar. It's also waste-free, because the material is made exactly to size with no off-cuts, Polestar said.

The wine industry could also provide a source of recycled materials, according to Polestar. Leftovers from the cork-making process -- or even whole corks from emptied wine bottles -- could be turned into PVC interior components, according to Polestar. And Nylon 6 from fishing nets could be recycled as well, and turned into carpets, Polestar said.

Polestar sustainable seat material

Polestar sustainable seat material

Another automaker is already running with the fishing-net idea. The Fisker Ocean electric crossover has carpets made from recycled ones. It also makes use of recycled rubber waste and features a material called "eco-suede," which is made from recycled plastic and polyester fibers.

Fisker has proclaimed the Ocean to be the "world's most sustainable vehicle." It's unclear if Polestar will try to challenge that with its future models.

Larger automakers are aiming to make strides in sustainability. For example, in a recent presentation to investors, General Motors CEO Mary Barra said the automaker wants 50% sustainable content in its cars by 2030. And Toyota has set a goal of making all operations emissions free by 2050, and plans to cut emissions from its United States operations by 40% over the next few years.

The newly-merged Fiat Chrysler Automobiles and Group PSA together have pledged to become "a world leader" in sustainability, although a concrete plan will likely have to wait until further details of the merger are ironed out.