WEATHER ALERT
Polar vortex makes much of US colder than Greenland, but warmth is coming. Then more cold
Read full article: Polar vortex makes much of US colder than Greenland, but warmth is coming. Then more coldThe polar vortex’s icy grip on much of America has Arctic Greenland seeming like a toasty vacation spot by comparison.
Trump administration orders halt to NYC toll meant to fight traffic and fund mass transit
Read full article: Trump administration orders halt to NYC toll meant to fight traffic and fund mass transitPresident Donald Trump’s administration has ordered a halt to New York City’s congestion pricing system, which thins traffic and funds mass transit by imposing high tolls on drivers entering some parts of Manhattan.
Winter-weary East Coast hit with another storm as temperatures plunge elsewhere
Read full article: Winter-weary East Coast hit with another storm as temperatures plunge elsewhereOfficials have urged residents to stay off the roads in portions of Virginia and North Carolina, where a storm dropped heavy snow and caused hundreds of accidents in places that aren’t accustomed to significant accumulations.
Trump's firing of 1,000 national park workers raises concerns about maintenance and operating hours
Read full article: Trump's firing of 1,000 national park workers raises concerns about maintenance and operating hoursThe Trump administration has fired about 1,000 newly hired National Park Service employees who maintain and clean parks, educate visitors and perform other functions as part of its broad-based effort to downsize government.
Sea turtles return to the Atlantic Ocean off Florida after being stunned by the cold
Read full article: Sea turtles return to the Atlantic Ocean off Florida after being stunned by the coldEight green sea turtles stunned by the cold during a rare snowfall in Florida have been released back into the Atlantic Ocean.
Mystical beliefs fuel Senegal’s illegal big cat trade and threaten lion’s survival in West Africa
Read full article: Mystical beliefs fuel Senegal’s illegal big cat trade and threaten lion’s survival in West AfricaThe illegal trade of lion and leopard parts is growing in Senegal and threatening the lion's survival across West Africa.
How better water systems can help a city survive the next firestorm
Read full article: How better water systems can help a city survive the next firestormRecent fires that consumed entire Los Angeles neighborhoods underscore a stark lesson -- water utilities generally aren’t designed to respond to the large urban fires growing more common as climate change worsens.
Judge approves emergency plan to keep Britain’s largest water company afloat
Read full article: Judge approves emergency plan to keep Britain’s largest water company afloatA judge has approved an emergency plan to keep Britain’s largest water company afloat and averted a possible temporary government takeover.
Rio de Janeiro's hottest day in at least a decade sends residents to the beach
Read full article: Rio de Janeiro's hottest day in at least a decade sends residents to the beachRio de Janeiro has recorded its hottest day in at least a decade when temperatures reached 44 degrees Celsius (111 F) as residents try to cool off in the ocean or under public showers.
Scientists are racing to discover the depth of ocean damage sparked by the LA wildfires
Read full article: Scientists are racing to discover the depth of ocean damage sparked by the LA wildfiresAs crews work to remove potentially hundreds of thousands of tons of hazardous materials from the Los Angeles wildfires, researchers and officials are trying to understand how the fires on land have impacted the sea.
Trump creates council for 'energy dominance,' boosts natural gas exports and offshore drilling
Read full article: Trump creates council for 'energy dominance,' boosts natural gas exports and offshore drillingPresident Donald Trump has signed an executive order formally creating a National Energy Dominance Council and directed it to drive up already record-setting domestic oil and gas production.
Major test case for new geothermal technology launches in small German town
Read full article: Major test case for new geothermal technology launches in small German townResidents in the German town of Geretsried have long wanted to run their buildings with clean heat and electricity from geothermal energy rather than fossil fuels.
As Trump administration reforms the EPA, cleanups of America's most toxic sites are uncertain
Read full article: As Trump administration reforms the EPA, cleanups of America's most toxic sites are uncertainFor nearly 100 years, the former Exide plant melted lead-acid car batteries that polluted properties in the mostly Latino region of southeast Los Angeles.
Very cold weather is coming. US about to get 10th and chilliest polar vortex this winter
Read full article: Very cold weather is coming. US about to get 10th and chilliest polar vortex this winterMeteorologists warn that the coldest burst of Arctic air this season is coming to put an icy and prolonged exclamation point on America’s winter of repeated polar vortex invasions starting this weekend.
Eastern U.S. braces for flooding while fire-damaged California city now faces mudslides
Read full article: Eastern U.S. braces for flooding while fire-damaged California city now faces mudslidesMuch of the Eastern U.S. braced for a renewed round of harsh, soggy weather on Saturday, with thunderstorms and melting snow combining to pound the Ohio and Tennessee valleys.
Thorny problems with Valentine’s roses: Invasive bugs and toxic pesticides hurt Kenya’s exports
Read full article: Thorny problems with Valentine’s roses: Invasive bugs and toxic pesticides hurt Kenya’s exportsThis Valentine's Day Kenya's flower industry is being ravaged by pests, leading some flower farmers to rely more heavily on toxic pesticides.
Trump wants states to clean up forests to stop wildfires. But his administration cut off funds
Read full article: Trump wants states to clean up forests to stop wildfires. But his administration cut off fundsPresident Donald Trump’s administration is holding up money for wildfire mitigation projects funded through legislation championed by his Democratic predecessor.
EPA chief says he will seek return of $20 billion in clean-energy grants awarded by Biden
Read full article: EPA chief says he will seek return of $20 billion in clean-energy grants awarded by BidenIn a major reversal, the new head of the Environmental Protection Agency says he'll try to rescind $20 billion in grants awarded by the Biden administration for climate and clean-energy projects.
Man whose wife was killed in a hippo attack in Africa sues the US company that booked the trip
Read full article: Man whose wife was killed in a hippo attack in Africa sues the US company that booked the tripA New Jersey man whose wife was killed in a hippopotamus attack last year during a safari in Africa is suing the U.S. company that arranged the trip.
What's an atmospheric river? A pineapple express? AP explains the weather phenomenon
Read full article: What's an atmospheric river? A pineapple express? AP explains the weather phenomenonAtmospheric rivers are long and relatively narrow bands of water vapor that form over an ocean and flow through the sky, transporting much of the moisture from the tropics to northern latitudes.
Innovators gear up work on ‘green’ hydrogen plane with plans for nonstop 9-day trip around Earth
Read full article: Innovators gear up work on ‘green’ hydrogen plane with plans for nonstop 9-day trip around EarthSwiss aviation pioneer Bertrand Piccard is developing a plane powered by liquid hydrogen after a much-hyped flight in 2015 that used sunlight to travel around the world.
Farmers and rural businesses shelled out money for improvements. Will their promised rebates arrive?
Read full article: Farmers and rural businesses shelled out money for improvements. Will their promised rebates arrive?A freeze on federal loans and grants is sending tremors across the rural U.S. as small business owners fear they won’t get reimbursed for purchases they made to replace polluting irrigation equipment or install solar power.
Heavy rain pummels slide-prone Southern California as crashes close roads in the Northwest
Read full article: Heavy rain pummels slide-prone Southern California as crashes close roads in the NorthwestHeavy rain is falling across Southern California, creating deluges of water and mud on roads at the bottom of hillsides left barren by recent wildfires.
Brazil's Lula backs oil exploration in the Amazon ahead of hosting UN climate talks
Read full article: Brazil's Lula backs oil exploration in the Amazon ahead of hosting UN climate talksBrazil's President Luiz Inácio Lula da Silva is defending oil exploration near the mouth of the Amazon River as a way to finance a transition to green energy.
Tar balls wash ashore on Florida beaches, but the source of the sticky black goo is a mystery
Read full article: Tar balls wash ashore on Florida beaches, but the source of the sticky black goo is a mysteryThe U.S. Coast Guard has been searching for tar balls that began showing up on Florida beaches over the weekend.
Eastern storm cuts power to tens of thousands as California braces for flooding
Read full article: Eastern storm cuts power to tens of thousands as California braces for floodingHeavy snow and freezing rain from Kentucky to the nation's capital caused hundreds of crashes and left tens of thousands of residents in the dark.
California's insurer for people without private coverage needs $1 billion more for LA fires claims
Read full article: California's insurer for people without private coverage needs $1 billion more for LA fires claimsCalifornia’s plan that provides insurance to homeowners who can’t get private coverage needs $1 billion more to pay out claims related to the Los Angeles wildfires.
India wants to embrace nuclear power. To do it, it'll need a lot of time and money
Read full article: India wants to embrace nuclear power. To do it, it'll need a lot of time and moneyIndia wants more nuclear power, has pledged over $2 billion toward research and will change laws to boost investment to do it.
Plastic straws have come to symbolize a global pollution crisis. Trump wants them to stay
Read full article: Plastic straws have come to symbolize a global pollution crisis. Trump wants them to stayStraws might seem insignificant, but the plastic straw has come to symbolize a global pollution crisis over the past decade.
'Back to plastic': Trump signs order for plastic straws as he declares paper ones 'don’t work'
Read full article: 'Back to plastic': Trump signs order for plastic straws as he declares paper ones 'don’t work'President Donald Trump says he is banning federal use of paper straws, saying they “don’t work” and don’t last very long.
Hawaii court rules against insurance companies in Maui wildfire, allowing $4B settlement to proceed
Read full article: Hawaii court rules against insurance companies in Maui wildfire, allowing $4B settlement to proceedHawaii’s Supreme Court has ruled that insurance companies can’t bring their own legal actions against those blamed for Maui’s catastrophic 2023 wildfire, the deadliest in the U.S. in more than a century.
Push to eliminate renewable energy goals in Puerto Rico sparks outrage as outages persist
Read full article: Push to eliminate renewable energy goals in Puerto Rico sparks outrage as outages persistPuerto Rico legislators have held a contentious public hearing on whether to scale back renewable energy goals and extend operations of its lone coal-fired plant, long accused of contaminating low-income communities.
Most nations miss deadline for plans to fight climate change. UN says take your time to do it right
Read full article: Most nations miss deadline for plans to fight climate change. UN says take your time to do it rightNearly 200 nations faced a Monday deadline to file what the United Nations’ climate chief calls “among the most important policy documents governments will produce this century."
Stricter lobster fishing rules scrapped after complaints from fishermen about harm to industry
Read full article: Stricter lobster fishing rules scrapped after complaints from fishermen about harm to industryFishing industry regulators have decided to scrap stricter new lobster fishing standards off New England in the wake of months of protest from lobster fishermen that the rules were unnecessary and would bankrupt harvesters.
Trump is trying to halt the EV charger buildout. Experts say it's not that easy
Read full article: Trump is trying to halt the EV charger buildout. Experts say it's not that easyExperts are questioning President Donald Trump’s latest effort to slow the electric vehicle charging buildout in the U.S. In a letter Thursday night, the Trump administration directed states to stop spending money for EV charging infrastructure, money they were allocated under former President Joe Biden.
WM's zero-waste approach to golf's raucous Phoenix Open catching on in the sports world
Read full article: WM's zero-waste approach to golf's raucous Phoenix Open catching on in the sports worldThe Phoenix Open’s famously booze-soaked 16th hole is one of the most unique spectacles in golf, where the normally gentile sport lets loose with stadium-style seating, deafening music and an enthusiastic announcer introducing players in a scene that’s more WWE than PGA Tour.
‘It looks like a stream of blood.’ A river near Buenos Aires turns red, sparking fears of toxic leak
Read full article: ‘It looks like a stream of blood.’ A river near Buenos Aires turns red, sparking fears of toxic leakA stream winding through a populous area on the outskirts of Buenos Aires has turned crimson red in recent hours that has sparked fears of industrial chemical dumping.
Efforts to put carbon dioxide underground face less support in Trump's second term
Read full article: Efforts to put carbon dioxide underground face less support in Trump's second termU.S. efforts to put carbon dioxide from power plants and industrial facilities underground where they won't contribute to global warming could see less federal support under President Donald Trump although demand for the technology remains high.
Indonesia orders the halting of tourism projects linked to Trump over environmental issues
Read full article: Indonesia orders the halting of tourism projects linked to Trump over environmental issuesOfficials say Indonesian authorities have ordered the halting of development of a tourism project affiliated with U.S. President Donald Trump over water management and environment issues.
22 states sue New York state, alleging environmental fund is unconstitutional
Read full article: 22 states sue New York state, alleging environmental fund is unconstitutionalTwenty-two states are suing New York state, contending that a new law forcing energy companies to pay $75 billion into a fund to cover climate change damage is unconstitutional.
Newsom wants to speed up a delayed rule to make California homes more fire resistant
Read full article: Newsom wants to speed up a delayed rule to make California homes more fire resistantCalifornia Gov. Gavin Newsom will order state officials to advance implementation of a state rule aiming to make homes more fire resistant during wind-driven wildfire after years of delay.
Winter storms bring flooding and 'thunder ice' in several US states
Read full article: Winter storms bring flooding and 'thunder ice' in several US statesThunderstorms caused flash flooding in portions of West Virginia and spawned a tornado in Kentucky, while a wintry mix coated trees and roads and even dropped “thunder ice” in several states.
Utility says its equipment may have started a small blaze that erupted during January's LA firestorm
Read full article: Utility says its equipment may have started a small blaze that erupted during January's LA firestormA California utility says its equipment may have sparked a small wildfire in Los Angeles that broke out the same day as two massive blazes in the area killed at least 29 people and destroyed thousands of homes.
How the nonprofit Change Reaction gets money to LA households impacted by wildfires so fast
Read full article: How the nonprofit Change Reaction gets money to LA households impacted by wildfires so fastAs Angelenos reel from the devastating wildfires that destroyed thousands of homes and businesses and killed at least 29 people, an LA-based nonprofit is giving some of those impacted fast, unrestricted help by handing out cash payments of as much as $5,000.
Freezing hikers stuck in waist-deep snow rescued during Mount Washington whiteout
Read full article: Freezing hikers stuck in waist-deep snow rescued during Mount Washington whiteoutTwo experienced hikers were rescued after an hourslong ordeal in which they became stranded in waist-deep snow and whiteout conditions on New Hampshire's challenging Mount Washington.
The US is freezing and La Nina usually eases warming. Earth just set another heat record anyway
Read full article: The US is freezing and La Nina usually eases warming. Earth just set another heat record anywayThe European climate service Copernicus says the world warmed to yet another monthly heat record in January, despite an abnormally chilly United States, a cooling La Nina and predictions of a slightly less hot year.
USAID is going away, and along with it cocaine-fighting efforts and Amazon rainforest protection
Read full article: USAID is going away, and along with it cocaine-fighting efforts and Amazon rainforest protectionThe dismantling of the U.S. Agency for International Development will deliver a major blow to efforts including humanitarian assistance in Colombia, conservation efforts in Brazil and coca eradication in Peru — South American countries that have been a priority for the support.
Colombia's president orders national oil company to cancel US venture over environmental concerns
Read full article: Colombia's president orders national oil company to cancel US venture over environmental concernsColombian president Gustavo Petro has ordered the state-run oil company Ecopetrol to cancel a joint venture with U.S.-based Occidental Petroleum that was expected to produce around 90,000 barrels of oil per day.
Trump administration will consider redrawing boundaries of national monuments as part of energy push
Read full article: Trump administration will consider redrawing boundaries of national monuments as part of energy pushInterior Secretary Doug Burgum has ordered federal officials to review and consider redrawing the boundaries of national monuments created under previous presidents to protect unique landscapes and cultural resources.
Making climate-friendly lifestyle choices isn't always easy. India learned the hard way
Read full article: Making climate-friendly lifestyle choices isn't always easy. India learned the hard wayA major government initiative to get people to think about their energy choices to pollute less — like cycling instead of driving or using less plastic — has received virtually no funding or publicity in the last year.
A North Carolina wildlife crossing will save people. Can it save the last wild red wolves too?
Read full article: A North Carolina wildlife crossing will save people. Can it save the last wild red wolves too?Red wolves once ranged far and wide across the U_S_, helping them earn the nickname “America's wolf.”.
Senate confirms fossil fuel CEO Chris Wright as energy secretary. He vows to 'unleash' US resources
Read full article: Senate confirms fossil fuel CEO Chris Wright as energy secretary. He vows to 'unleash' US resourcesThe Senate has confirmed fossil fuel executive Chris Wright to serve as energy secretary, a key post to promote President Donald Trump’s efforts to achieve U.S. “energy dominance” in the global market.
Dramatic drop in monarch butterfly count nears record 30-year low
Read full article: Dramatic drop in monarch butterfly count nears record 30-year lowThe number of monarch butterflies spending the winter in the western United States dropped dramatically this year even as federal officials move to extend protections for the beloved pollinator.
Court restores protections for endangered whale species to prevent entanglement in fishing gear
Read full article: Court restores protections for endangered whale species to prevent entanglement in fishing gearA federal appeals court is reinstating rules designed to protect a vanishing whale species from entanglement in fishing gear.
Pacific Coast Highway reopens nearly a month after devastating Southern California wildfires
Read full article: Pacific Coast Highway reopens nearly a month after devastating Southern California wildfiresThe Pacific Coast Highway is back open in Malibu, California, nearly a month after the deadly Palisades Fire ripped through hillside Los Angeles neighborhoods, destroying properties all the way down to the beach.
Nigeria moves to restart oil production in vulnerable region after Shell sells much of its business
Read full article: Nigeria moves to restart oil production in vulnerable region after Shell sells much of its businessThe Nigerian government is in talks with local communities to restart oil production in a region that’s previously suffered environmental damage after oil giant Shell’s sale of its onshore business in the country.
Surreal prices for COP30 in Brazil's Amazon leave attendees scrambling for a place to stay
Read full article: Surreal prices for COP30 in Brazil's Amazon leave attendees scrambling for a place to stayNine months ahead of the 2025 U.N. climate conference known as COP30, prices for lodging are alarming those who want to attend the event in Belem, Brazil’s Amazonian host city.
Lawsuit blames deaths on Ohio train derailment as Vance says US needs 'to do better on rail safety'
Read full article: Lawsuit blames deaths on Ohio train derailment as Vance says US needs 'to do better on rail safety'A new lawsuit alleges for the first time that people died because of the disastrous 2023 East Palestine, Ohio, train derailment.
Southeast Asia looks to nuclear power to supercharge its energy transition
Read full article: Southeast Asia looks to nuclear power to supercharge its energy transitionMost countries in fast-growing Southeast Asia are looking to develop nuclear energy in their quest for cleaner and more reliable energy.
As crews clean up from LA wildfires, some residents are furious over hazardous waste
Read full article: As crews clean up from LA wildfires, some residents are furious over hazardous wasteAs crews work to clean up from the Los Angeles wildfires, city officials and residents are opposing the designation of a federally owned park to process hazardous waste.
Rats! More rodents are infesting cities as scientists say warmer temperatures mean more rat babies
Read full article: Rats! More rodents are infesting cities as scientists say warmer temperatures mean more rat babiesA new study finds that rat infestation in many of the world’s cities appears to be soaring, especially in Washington.
Man agrees to plead guilty for flying drone that damaged firefighting aircraft in LA wildfire
Read full article: Man agrees to plead guilty for flying drone that damaged firefighting aircraft in LA wildfireA man who launched a drone from the top of a parking structure and lost sight of it has agreed to plead guilty to unsafely operating a drone after it left a gaping hole in the wing of a firefighting aircraft during the deadly Palisades Fire in Los Angeles.
In win for Trump, oil giant Shell walks away from major New Jersey offshore wind farm
Read full article: In win for Trump, oil giant Shell walks away from major New Jersey offshore wind farmIn the first serious fallout from President Donald Trump’s early actions against offshore wind power, oil and gas giant Shell is walking away from a major project off the coast of New Jersey.
Experts and advocates warn of nickel mining's risk to precious marine region of Indonesia
Read full article: Experts and advocates warn of nickel mining's risk to precious marine region of IndonesiaA new report says the expansion of nickel mining in Indonesia is a threat to one of Earth's most biodiverse marine regions.
Big Oil wants a lot from Trump. It has an ally in Doug Burgum, the president's Interior pick
Read full article: Big Oil wants a lot from Trump. It has an ally in Doug Burgum, the president's Interior pickEmails obtained by The Associated Press reveal Doug Burgum as North Dakota governor catered to the whims of oil and gas executives while leveraging those connections to expand his political profile.
Study finds India doubled its tiger population in a decade and credits conservation efforts
Read full article: Study finds India doubled its tiger population in a decade and credits conservation effortsIndia doubled its tiger population in a little over a decade by protecting the big cats from poaching and habitat loss, ensuring they have enough prey, reducing human-wildlife conflict, and increasing communities’ living standards near tiger areas.
European court finds Italy violated the right to life of Italians living in Naples toxic dump area
Read full article: European court finds Italy violated the right to life of Italians living in Naples toxic dump areaThe European Court of Human Rights has ruled that Italy violated the right to life of Italians living in a toxic-waste polluted area around Naples.
A New Zealand mountain is granted personhood, recognizing it as sacred for Māori
Read full article: A New Zealand mountain is granted personhood, recognizing it as sacred for MāoriA mountain in New Zealand considered an ancestor by Indigenous people has been recognized as a legal person after a new law granted it all the rights and responsibilities of a human being.
A food bank netted a huge haul of 13,000 fresh salmon. The catch? The fish were still alive
Read full article: A food bank netted a huge haul of 13,000 fresh salmon. The catch? The fish were still aliveAn upstate New York food bank was offered more than 40,000 pounds of coho salmon — a bountiful feast.
Russia comes in from the cold, with flowers blooming around Moscow in January
Read full article: Russia comes in from the cold, with flowers blooming around Moscow in JanuaryJanuary in Russia conjures up images of Muscovites crunching through the snow in bulky coats -- not bunches of delicate snowdrops blooming in grassy areas around still-standing Christmas trees.
Record levels of 'forever chemicals' found in wildlife near New Mexico base, hunters warned
Read full article: Record levels of 'forever chemicals' found in wildlife near New Mexico base, hunters warnedEnvironmental regulators and health officials in New Mexico are warning hunters that harmful chemicals known to cause cancer in people have been found at record levels in birds, small mammals and plants at a lake near Holloman Air Force Base.
Trump rescinds funding freeze but uncertainty lives on for wide array of environmental programs
Read full article: Trump rescinds funding freeze but uncertainty lives on for wide array of environmental programsA chaotic back-and-forth over President Donald Trump’s freeze on federal grants and loans has farmers, activists, organizations and businesses wondering whether they will receive the funding they rely on.
Independently funded jet's sound barrier mark revives talk of commercial supersonic travel
Read full article: Independently funded jet's sound barrier mark revives talk of commercial supersonic travelAn aircraft developed by Boom Supersonic has become the first independently funded jet to break the sound barrier.
Senate confirms Zeldin to lead Environmental Protection Agency as Trump vows to cut climate rules
Read full article: Senate confirms Zeldin to lead Environmental Protection Agency as Trump vows to cut climate rulesThe Republican-controlled Senate has confirmed Lee Zeldin to lead the Environmental Protection Agency.
Cold-stunned green sea turtles are recovering at a Florida marine life center
Read full article: Cold-stunned green sea turtles are recovering at a Florida marine life centerAn arctic blast that brought a rare snowfall to northern Florida last week left green sea turtles as far south as St. Augustine suffering from a condition known as cold stunning.
Things to know about the Trump administration order on miles per gallon for cars and pickups
Read full article: Things to know about the Trump administration order on miles per gallon for cars and pickupsHours after being sworn in as the new U.S. Secretary of Transportation, Sean Duffy took aim at the main way the federal government regulates miles per gallon for cars and pickup trucks — also a principal way that it controls air pollution and addresses climate change.
Pauses on US foreign aid and other grants send funders and nonprofits scrambling
Read full article: Pauses on US foreign aid and other grants send funders and nonprofits scramblingThe Trump administration has made or initiated major policy changes that impact nonprofits and their missions in its first week.
UK government backs contentious third runway at London's Heathrow Airport
Read full article: UK government backs contentious third runway at London's Heathrow AirportU.K. Treasury chief Rachel Reeves says that the new Labour government is backing the construction of third runway at London’s Heathrow Airport.
An unlikely symbol of cooperation, the barn owl brings Arab and Israeli scientists together
Read full article: An unlikely symbol of cooperation, the barn owl brings Arab and Israeli scientists togetherA cross-border conservation project centered on barn owls is fostering cooperation between Israeli and Arab scientists, offering a rare example of coexistence in the conflict-ridden Middle East.
Tiger poachers use fishing boats to smuggle body parts out of Malaysia, study shows
Read full article: Tiger poachers use fishing boats to smuggle body parts out of Malaysia, study showsCommercial fishing fleets have been playing a key role in the trafficking of parts of tigers poached in Malaysia, according to new research, information that could help enforcement efforts to save the critically endangered cat.
DeepSeek says it built its chatbot cheap. What does that mean for AI's energy needs and the climate?
Read full article: DeepSeek says it built its chatbot cheap. What does that mean for AI's energy needs and the climate?Chinese artificial intelligence startup DeepSeek stunned markets and AI experts with its claim that it built its immensely popular chatbot at a fraction of the cost of those made by American tech titans.