Hundreds of commercial flights will be told to change their paths over the northeastern Atlantic Ocean during the next two winters to show how minor altitude adjustments can reduce aviation's climate impact.
The British government is backing the landmark airspace-scale trial, launched Tuesday, to avoid creating condensation trails, or contrails. Google UK is contributing its artificial intelligence-powered forecasts to identify the contrail regions.
When airplanes fly through cold and humid areas, ice crystals can form around the soot particles emitted from the engine, creating clouds that trap heat and warm the planet. The Shanwick Oceanic Control Area in the eastern half of the North Atlantic corridor, the location of the trial, is a busy gateway for air traffic between Europe and North America. It's also a hot spot for where contrails form.
The 30-month research program known as Operation Blue Skies includes test periods this winter and next, when air traffic controllers will tell some flights to deviate up to 2,000 feet (610 meters) to avoid areas where contrails are likely to form. These will be minor altitude adjustments within standard flight operations, coordinated through established air traffic control communication channels, according to the British government.
There will be about 20 to 40 test days per winter, when there is less air traffic. Around 10,000 flights are expected to pass through the Shanwick airspace during the testing. Hundreds of those flights would deviate their routes. That 1 % to 5% would be enough to demonstrate a statistically significant reduction in contrail formation on an airspace-scale, said Paul Hodgson, Google's technical lead for Operation Blue Skies.
Individual airlines have tested shifting altitudes to avoid contrail regions. Earlier this year, Google and American Airlines announced that the airline significantly reduced the climate impact of some flights using Google’s AI-based forecasting tool to help prevent contrails.
This new effort expands on individual airline trials to try mitigating contrails across an entire flight corridor.
The thin, white lines that form behind airplanes are responsible for a surprising amount of Earth’s warming — 1% to 2%, according to Contrails.org, a nonprofit research organization dedicated to reducing aviation’s climate impact through contrail management, as part of the Breakthrough Energy group founded by Bill Gates. Modeling shows that the Shanwick airspace accounts for about 5% of the total contributed by contrails, with a significant amount occurring during winter.
Keir Mather, the UK minister responsible for aviation, said the government is partnering with Google to back British experts and innovators to find practical ways to make flying cleaner. The government is paying for more than half of the 5 million pound ($6.76 million) study.
Google called contrails one of the most urgent yet solvable climate challenges facing aviation today.
Hodgson said testing over an airspace, versus individual airline trials, can show how it's possible to move multiple planes away simultaneously from an area where contrails will form, and can show if contrails can be reduced overall for a region. This could provide a blueprint for similar airspaces, he added.
Along with Google and the UK Department for Transport, the consortium includes the Met Office, the UK’s leading air navigation service provider NATS, Contrails.org, Imperial College London and the University of Cambridge.
An Imperial College London study in 2020 found that small changes to flight paths could reduce the climate impact of contrails. Professor Marc Stettler said Operation Blue Skies is a chance to test that idea in the real world, on a scale never seen before.
The Associated Press’ climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.
FILE - An airplane flies high in the sky with the moon in the background in Garmisch-Partenkirchen, Germany, Jan. 1, 2023. (AP Photo/Matthias Schrader, File)
JUNEAU, Alaska (AP) — Alaska voters are choosing candidates for November's general election in a series of primary contests Tuesday, including a U.S. Senate race that will be among the most closely watched in the nation this fall.
The campaign featured over a dozen contenders in each of the top races — for Senate, U.S. House and governor. Under Alaska’s open primary system, all candidates appear on the same ballot, and the four who receive the most votes qualify for the ranked vote general election.
Tuesday's ballot also included candidates running for the Legislature and a statewide initiative that would reimpose campaign contribution limits in state and local elections.
The highest-profile candidates in a field of 16 were two-term Republican Sen. Dan Sullivan and Democratic former U.S. Rep. Mary Peltola.
The race, which could help determine control of the Senate, has drawn significant attention from outside groups, with Republican and Democratic campaign organizations identifying it as a top target. Peltola shook up her campaign leadership days before the primary.
During the campaign, Sullivan, a veteran and ally of President Donald Trump, emphasized his support for the military, efforts to open more land for oil development and Trump's signature tax and spending bill passed last year. He accused Peltola of being aligned with Lower 48 “liberals.”
Peltola leaned into the “fish, family, freedom” slogan that first got her elected in 2022. She has criticized a political system that she said is rigged by special interests and allows politicians to enrich themselves.
But it was a third candidate, a Republican also named Dan Sullivan, who garnered much of the attention.
Dan J. Sullivan won a legal fight to appear on the ballot following claims by the senator and GOP allies that he was a sham candidate running at the behest of Democrats with the intent of causing confusion. Dan J. Sullivan, a retired teacher from the island community of Petersburg, denied that and said his run was spurred by frustration with the incumbent.
He appeared on the ballot as Daniel J. Sullivan Jr., with no party affiliation — a decision that a state elections official said was intended to minimize possible confusion. Meanwhile, the senator was listed as Dan S. Sullivan, Republican and incumbent. The “incumbent” label does not accompany the names of any other candidates seeking reelection.
The drama involving the dueling Dan Sullivans caught the attention of Trump. In a social media post endorsing the senator days before the primary, he called the other's candidacy an attempt to trick voters and urged his followers to vote for “SULLIVAN, DAN S.”
In the race for Alaska's only House seat, the most prominent candidates were Republican Rep. Nick Begich, seeking a second term, and independent Bill Hill, a fisherman and former educator from a small southwestern village.
Progressive Democrat Matt Schultz suspended his campaign last month but remained on the ballot. His campaign said Schultz would withdraw as a general election candidate if he makes the primary's top four.
Schultz urged support for Hill, who leaned into concerns about affordability. Begich, who was endorsed by Trump, cast himself as hardworking and effective in his role. House Speaker Mike Johnson appeared at a rally for Begich in a conservative part of the state this month, though the event was closed to news media.
The campaign for the state’s top executive office was an open race this year because Republican Gov. Mike Dunleavy was barred by term limits from seeking a third consecutive stint.
Two Democrats hope to emerge from a crowded, largely Republican field: former state lawmakers Jonathan Kreiss-Tomkins and Tom Begich, who is Nick Begich's uncle. If one of them wins in November, he would become Alaska's first Democratic governor since Tony Knowles left office in 2002.
Republicans in the race included Bernadette Wilson, a businessperson and conservative activist; Click Bishop, a former state labor commissioner and lawmaker; Dave Bronson, former mayor of Anchorage; and Adam Crum and Treg Taylor, two former members of Dunleavy's Cabinet.
Former Gov. Bill Walker, an independent, was also on the ballot.
The lone measure before voters on the primary ballot asked them to reimpose campaign contribution limits five years after a divided federal appeals court struck down a number of caps.
The measure proposes a $2,000 limit on how much individuals can give to candidates in state and local elections and a $5,000 cap on what they can give to political parties. It would also limit spending by groups other than political parties and how much individuals and groups can give to joint campaigns for governor and lieutenant governor.
Supporters say such limits are needed to prevent special interests and wealthy donors from having outsize influence on a campaign or race. Opponents say the measure would favor candidates with name recognition and argue that restricting what someone can contribute limits their voice.
Political spending by wealthy people has become a flashpoint in races in Alaska and elsewhere. In 2025 in Wisconsin, billionaires Elon Musk and George Soros helped push spending in a state Supreme Court campaign past $100 million, the most ever for a court race in the U.S.
FILE - Alaska Republican U.S. Rep. Nick Begich walks down a corridor in the state Capitol before giving a speech to Alaska lawmakers, March 10, 2026, in Juneau, Alaska. (AP Photo/Becky Bohrer, File)
FILE - Alaska U.S. House candidate Bill Hill, an independent, speaks with people at a campaign fundraising event in Juneau, Alaska, June 4, 2026. (AP Photo/Becky Bohrer, File)
FILE - Dan Sullivan, a candidate in Alaska's U.S. Senate race who shares his name with the incumbent seeking reelection, talks with a reporter, July 3, 2026, in Petersburg, Alaska. (AP Photo/Becky Bohrer, File)
FILE - Sen. Dan Sullivan, R-Alaska, speaks to reporters at the Capitol in Washington, June 30, 2025. (AP Photo/Mark Schiefelbein)
FILE - Alaska U.S. Senate candidate Mary Peltola, a Democrat, speaks during a campaign rally on May 14, 2026, in Juneau, Alaska. (AP Photo/Becky Bohrer, file)
