Airlines like United and American are betting on electric air taxis that could change the way we get around and between cities — here's the 8 companies they're partnering with

• The aviation industry emits hundreds of millions of tons of CO2 into the atmosphere every year.
• The industry has committed to net-zero emissions by 2050 to better battle climate change.

EVTOLs are low or zero-emission urban air mobility aircraft that are primarily marketed as short-haul air taxis. The vehicles are ideal for populated areas with no runways or other infrastructure needed by commercial jets and can offer efficient, fast transport in cities that are typically congested with roadway traffic.

Manufacturing giants like Boeing and Airbus are developing new eVOTLs to revolutionize air travel, like Boeing-backed Wisk and Airbus' all-electric, four-seater CityAirbus NextGen.

While low-emission sustainable aviation fuel is one promising solution for the global airline industry to lower its carbon emissions and reach net-zero carbon emissions by 2050 as mandated by the International Civil Aviation Organization, manufacturers and airlines will need to invest in additional technologies to meet the 2050 goal, with many turning to electric aircraft like eVTOLs.

The future of the new type of aircraft is promising, but even the soonest projections put it years away from entering service. Experts also note that there are still difficulties that have not been solved yet, like the lack of current infrastructure to support the new vehicles as well as the lack of any federal regulatory standards.

Additionally, it's impossible to be sure how the flying public will take to the new kind of aircraft once they can book trips on it.

Despite the potential hurdles, several airlines worldwide have taken interest in eVTOLs and electric planes, with the notable exception of Delta Air Lines, which is the only major US carrier that has not yet made a commitment.

Here's a look at the airlines that have invested in electric planes and eVTOLs with the hope they will one day provide an efficient, eco-friendly mode of transportation.

Vertical Aerospace's VX4

Vertical Aerospace's VX4 aircraft has received interest from airlines in every corner of the world, having amassed over 1,400 pre-orders for the VX4 as of June 30. The company hopes the aircraft will be certified by 2025 and flying soon after that.

Airline investors include American, Virgin Atlantic, Spanish charter airline Iberojet, Japan Airlines, Brazil-based GOL, Air Greenland, and AirAsia, according to the company. The latter three are via placements made by aircraft leasing company Avolon, which has ordered over 500 VX4s.

Embraer's Eve

Eve is Embraer's eVTOL four-seater product that has a backlog of over 1,900 aircraft.

The manufacturer has partnered with several carriers worldwide to promote urban air mobility, like Florida's Global Crossing Airlines, Australia's Sydney Seaplanes, Dubai's Falcon Aviation Services, Kenya Airways' subsidiary Fahari Aviation, Western Australia-based Aviair, US regional airlines Republic Airways and SkyWest Airlines, Singapore-based startup Ascent, and helicopter operators Halo and Helisul Aviation.

United is the most recent carrier to announce an investment in Eve. On Thursday, the carrier put down $15 million for a conditional order for 200 eVTOLS, with an option for 200 more. Eve hopes its eVTOL will be flying passengers as soon as 2026.

Airbus' CityAirbus NextGen

Airbus hopes to shake up the flying taxi market with its eVTOL product, CityAirbus NextGen. The four-seater vehicle can fly up to 60 miles, making it a viable candidate for intra-city flying. NextGen builds upon Airbus' original CityAirbus with a new design that includes fixed wings and a V-shaped tail.

With the announcement of the modified eVTOL, the company said it plans to conduct test flights in 2023 and get the flying taxi certified by 2025.

The planemaker has partnered with Italy's ITA Airways to "explore the creation of tailored UAM services, by identifying strategic use cases for emission-free mobility solutions."

Joby Aviation's eVTOL

Joby Aviation took over Uber Elevate — the company's air taxi arm — in 2020. The manufacturer has since partnered with Toyota to create a five-seater eVTOL, and Tokyo-based All Nippon Airways to bring the electric vehicle to Japan.

Like many of its competitors, the manufacturer hopes to get its air taxi flying as soon as 2024.

Heart Aerospace's ES-19

While not an eVTOL, Heart Aerospace is marketing a 19-seater electric plane, dubbed the ES-19. United has ordered 100 of the type once the aircraft meets the airline's "safety, business and operating requirements." The carrier's regional partner Mesa Airlines has also ordered 100 ES-19s, and New Zealand-based Sounds Air plans to have "at least three" ES-19s in its fleet by 2026.

Meanwhile, Finland flag carrier Finnair, Swedish airline BRA, Norway's Wideroe, Air Greenland, Quebec-based Pascan, California's Quantum Air, UK startup CityClipper, and Scandinavian Airlines have all signed letters of intent for the aircraft, according to the company.

Archer Aviation's "Midnight" Air Taxi

In mid-August, United announced its $10 million deposit for 100 of Archer Aviation's "Midnight" eVTOLs. Midnight will not be unveiled until later this year, a company spokesperson told Insider, but it has a prototype of its smaller "Maker" eVTOL that has been undergoing flight testing since December 2021.

United hopes to get "Midnight" in service by 2024.

Rolls-Royce's P-Volt

In March 2021, Rolls-Royce announced a partnership with airframer Tecnam and Norwegian regional airline Widerøe to develop the P-Volt electric aircraft. The zero-emission plane is expected to enter service in 2026.

Lilium's eVTOL Jet

German aircraft manufacturer Lilium has partnered with Brazilian airline Azul to create a "co-branded network in Brazil" using the seven-seater Lilium Jet. Lilium plans to sell 220 eVTOLs to Azul, which would operate and maintain the fleet.

The deal is worth $1 billion, with flights expected to start in 2025, though the aircraft should be ready for use by 2024.