The warming planet is changing the ecosystem. It's also bad for automakers.

When Swedish automaker Volvo opened its proving ground in Kiruna, Sweden, 30 years ago, the mission was clear: "Making sure that our products are truly fit for the harshest of winter conditions."

The remote location was ideal. Kiruna, situated about 90 miles north of the Arctic Circle, historically has long, cold winters and snow cover until mid-May. This year, Volvo engineers have been forced to postpone their annual testing or rely on subarctic cold boxes to replicate the region's harsh conditions.

"Normally we're used to a long season of winter testing," John Lundegren, an engineering manager at Volvo, told ABC News. "The season is getting more unpredictable. You can have warm weather in the middle of the winter. What happens is the snow melts and you have icy conditions. We've seen the weather start to change in the last five years."

The unpredictable weather can delay a vehicle's rollout and production schedule and interfere with critical testing of new vehicles: braking, battery heating, thermal management, performance and drivability and even cabin heating and defrosting.

"We have people coming to do brake testing, but we don't have any snow on the tracks," Lundegren explained. "So we have to wait for snowy conditions, and I don't think we have that in the pipeline for 10 days. It impacts how efficient we can be."

He went on, "We're trying to develop cars faster and faster, so having this short period of time where we can do the very important winter testing affects our whole development process."

Sven Albiecht, a chassis and drivetrain development engineer at Volkswagen, said the above-normal temperatures in Sweden and northern Scandinavia have been "difficult" for the German automaker.

"We need freezing conditions," he told ABC News. "We're testing later and ending earlier. ... The work is a little more compressed."

Like Volvo, Volkswagen parks vehicles overnight in fridgelike chambers to study how the cold affects a vehicle's responsiveness. The chambers are often more reliable than Mother Nature.

"We have to make sure the doors open at minus 40 degrees," Albiecht said.

Ice and slippery surfaces are also essential for tuning a vehicle's anti-lock braking system and electronic stability program, he added.

The volatile weather has not yet convinced Volkswagen to find new testing sites. But Albiecht said he's well aware that "something is happening. That is a fact."

According to Erik Kjellstr?m, a professor in climatology at the Swedish Meteorological and Hydrological Institute (SMHI), the snow cover in large parts of Sweden is much less this year when compared to previous years.

"There is usually much more snow right now. It's been rainy and slushy in northern parts of the country and the coast," he told ABC News. "The winter season keeps getting shorter and starting later. People are disturbed."

He pointed out that the average temperature in Sweden has "gone up quite a lot" in the last few decades. SMHI predicts Sweden's average annual temperature will be 2 to 6 degrees Celsius higher by the end of the century, "depending on how much greenhouse gas emissions continue."

What's more, northern Sweden will likely see the greatest change in temperature and "winters that are both significantly warmer and colder than the average climate," according to SMHI. And in southern Sweden, the number of days with snow cover has decreased. "Many winter industries are dependent on snow and are kept back if the snow cover is too thin and sporadic," according to SMHI.

"We are living through these changes, and it's quite frightening," Kjellstr?m said. "There's been a strong impact on wildlife and nature."

Polestar, the Swedish electric performance car brand, runs tests on its vehicles in Jokkmokk, a small town located in the Arctic Circle. The erratic weather there is raising alarms for the company's engineers.

"The winter testing in Jokkmokk allows our engineers to fine-tune the steering, balance the chassis and push the brake predictability to the max in the most extreme conditions," a spokesperson told ABC News. "But cold weather isn’t something we can take for granted anymore, not even in Swedish Lapland. Climate change is real, and our mission is to accelerate the shift to sustainable mobility."

Companies that perform annual winter vehicle tests in the United States are seeing similar climate-related dilemmas. Jake Fisher, who oversees Consumer Reports' auto testing program, said he and his team have traveled from Colchester, Connecticut, to the Canadian border to get their work done.

"It costs quite a bit of money to travel north to get these snow conditions," Fisher told ABC News. "The warmer temperatures are affecting our testing, too. The development [of vehicles] will get more expensive. Automakers will have to follow the weather and go farther north."

The lack of snow and mild weather cannot impede these necessary tests, he argued.

"Automakers are making sure all of the vehicle's components operate at extremely cold temperatures," Fisher said. "The heating system, the powertrain cooling, making sure windows defrost and stay defrosted -- engineers do a lot of work. If automakers can't get this weather, they can't validate the car."

Bridgestone, the tire and rubber company, sends its engineers around the globe to test how the company's tires perform in varying terrains and harsh environments. Tire testing can take weeks or even months in locales such as Colorado, Michigan, Finland and Sweden, with drivers observing understeer, oversteer and tire recovery. Last year, a series of tests scheduled to take place in Michigan had to be canceled because of unexpectedly warm weather.

"The conditions were fantastic until the week before we were slated to go," Matthew Thomas, manager of consumer marketing intelligence at Bridgestone, told ABC News. "Then the temperature rose and there was a lot of rain -- it degraded the testing surfaces in a way we didn't feel confident in the testing. We scraped the testing."

He added, "The weather is very unpredictable week over week."

An abnormal winter season does not mean motorists can forgo winter tires, he said.

"There will always be a need for winter-capable tires," he said. "When one region has a mild winter, another region may have a very severe winter. Snow and ice continue to be a major cause of collision for drivers."

Subzero temperatures are even more consequential for battery electric vehicle (BEV) testing. Volvo's Lundegren said he and his fellow engineers are still understanding how to make these batteries more efficient in bone-chilling temperatures.

"In the past, we had an issue with just starting the vehicle," he said. "That's why we have so many cold boxes this year. BEVs are still new for us in certain aspects. How do you optimize the battery for heat, for the propulsion? Finding the sweet spot on how to use as little energy as possible is really important when it comes to BEV tuning."

Fisher pointed out that cold weather is an electric vehicle's worst enemy.

"EVs do have range issues in the cold -- there's no question," he said. "The efficiency of EVs plummet in cold temperatures. The range can be cut by up to half. It takes so much electricity to warm the vehicle."

Albiecht, however, argued that gasoline and diesel engines may not always work perfectly in winter either.

"Diesel has to burn, and burning in very low temps is more difficult -- it's like starting a fire in the cold," he said. "There are a lot of mechanical parts in an internal combustion engine. Electric cars have no oil, no fluids and fewer parts. They are more simple. An electric motor never has problems starting."

Benny Leuchter, a Volkswagen factory race and test driver, has traveled the world to test-drive vehicles. The weeks and months analyzing vehicles in extreme temperatures is "tough on the engineers," he conceded. What's learned in the Arctic, though, has real-world consequences for consumers.

"We're developing our all-wheel drive and electric systems. ... Driving dynamics should work on dry, wet and snowy roads," he told ABC News. "It's worth it to develop and test these cars under these very hard conditions so the cars work every time."