The world is bidding farewell to a decade that will be remembered for the rise of social media, the Arab Spring, the #MeToo movement and President Donald Trump.
Below is a look at how the world is ushering in 2020, starting with the first to enter the new decade in New Zealand and Australia:
2020 reaches Hawaii
Revelers packed beaches from Waikiki to the Big Island as Hawaii residents and visitors rang in the new decade.
On Oahu, people packed the streets of Waikiki, where a fireworks display welcomed 2020. But across the island at Ko Olina and Turtle Bay resorts, people gathered to the sounds of bumping music as tiki torches burned along walkways.
Fireworks displays both big and small were held across the islands as the sanctioned shows competed with the less legal versions of the explosive festivities in neighborhoods on every island.
At Ko Olina Resort on Oahu's west side, people watched the sun dip below the horizon of the Pacific as the sky turned shades of orange and red before a deep blue sky took over. A traditional Hawaii luau was held later in the evening, with fire and hula dancers to entertain the crowds.
- CBS/Associated Press
Los Angeles celebrates 2020
Tens of thousands of people ushered in 2020 in downtown Los Angeles, gathering at Grand Park for the city's biggest free music and dance party. The gates opened shortly after 8 p.m. for the massive set-up in front of City Hall, but sound and light checks had gone on all day for the 7th annual Grand Park and the Music Center's New Year's Eve L.A.
The event was billed as the city's go-to central gathering place and it is the West Coast's flagship New Year's celebration complete with live music. But beyond the entertainment, the celebration featured more than 40 food trucks serving up tasty eats for a crowd expected to be about 50,000.
The main rule for the night? No alcohol was allowed.
"It's a low-key event, a mellow crowd," Paul Parkhurst, an attendee, said. "You don't have to worry about the effects of people drinking and driving. I don't have to worry about drinking and getting a ride back anywhere, so that's why I like this event better."
- CBS Los Angeles
The Big Apple ushers in 2020
Fireworks burst and confetti fell as throngs of revelers cheered the start of 2020 in New York City's Times Square. In one of the globe's most-watched New Year's Eve spectacles, the crowd counted down the last seconds of 2019 as a luminescent crystal ball descended down a pole.
About 3,000 pounds of confetti showered the sea of attendees, many of whom were also briefly rained on earlier in the evening as they waited in security pens for performances by stars including rap-pop star Post Malone, K-pop group BTS, country singer Sam Hunt and singer-songwriter Alanis Morissette.
The crowds packed into the heart of Manhattan mouthed lyrics and waved yellow and purple balloons in a frenzy as midnight approached.
"It was a dream, I wanted to do it so this year a lot of people helped me to get here so I'm here, and I'm thankful for that," said Mariemma Mejias, 48, who flew to New York for the festivities from San Juan, Puerto Rico.
The fun was evident, but some important global issues were driven home as well.
Spotlighting efforts to combat climate change, high school science teachers and students pressed the button that begins the famous 60-second ball drop and countdown to the new year.
-The Associated Press
Nearly 34,000 pounds of fireworks light up the sky in Brazil
About 3 million people welcomed 2020 at Brazil's iconic Copacabana beach as almost 34,000 pounds of colorful fireworks went off for 14 minutes after midnight.
Rio de Janeiro holds one of the biggest New Year parties in the world, with music, drinks and religious rituals on the shores. Many dress in white in a traditional sign of their hope for peace. About 2,000 policemen are working to ensure party-goers are safe, and authorities say only minor incidents have been reported so far.
Many locals and tourists are expected to stick around Copacabana until Wednesday's sunrise for their first dip of the year in the ocean, expecting to wash away their troubles from 2019.
The party in Sao Paulo, Brazil's metropolis, took about 2 million people to Paulista Avenue, the city's main road. Nearly all the 6,000 pounds of fireworks used there were silent, so pets would not be too bothered by the noise.
—The Associated Press
300,000 expected on the Las Vegas strip
Tourism officials expect more than 300,000 revelers for fireworks fired at midnight from atop seven casinos on the resort-lined Las Vegas Strip. Thousands more were expected for live music and an LED light and sound show at the downtown Fremont Street Experience pedestrian mall.
"I tell people to expect one of the better fireworks they're ever going to see," said Michael Austin, a country music singer from Nashville, Tennessee, who was booked to perform in Las Vegas. "Swarms of people getting along, bringing in the new year."
Juan and Isabel Tinajero, making their first family visit to Las Vegas, told The Associated Press they hoped 2020 would bring less stress than 2019.
"I expect a great show," Juan Tinajero said, as Isabel pushed a stroller along the Las Vegas Strip sidewalk. "It's Vegas, right?"
—The Associated Press
Fireworks light up the sky over world's tallest building in Dubai
For nearly 10 minutes, fireworks lit the sky over Dubai's Burj Khalifa, the world's tallest building, as hundreds of thousands gathered downtown to watch the spectacular display.
The New Year's Eve display at the 828-meter-tall (2,716-foot-tall) skyscraper was just one of seven different fireworks shows across the emirate. Tourists, especially from Europe and Russia, flocked to the sunny beaches of Dubai at this time of year to escape the cold, dark winter.
To keep the massive crowds safe, police created walkways around the Burj Khalifa tower for male-only groups to separate them from families and women.
Dubai will be hosting Expo 2020 this year, a world fair that brings the most cutting-edge and futuristic technologies.
—The Associated Press
Parisians flock to the Champs-Elysees despite massive transportation protests
A joyful crowd of Parisians and tourists walked, biked and used scooters to reach the Champs-Elysees for the new year celebrations, in a city with almost no public transport.
Revelers converged at the famous avenue to watch a light show at the Arc de Triomphe, followed by a fireworks display at midnight. Paris police set up a security perimeter around the Champs-Elysees area with a ban on alcohol and traffic restrictions.
All metro lines in the French capital were closed except for two automatic lines, and only a few night buses were running, as Tuesday marked the 27th consecutive day of transport strikes against President Emmanuel Macron's plans to overhaul the French pension system.
—The Associated Press
New Year's in Moscow: Fireworks, Putin, but no snow
Russians welcomed New Year's Eve with fireworks and a message from President Vladimir Putin urging them to work together in the coming year.
Putin made the call in a short, pre-recorded speech broadcast on television just before the stroke of midnight in each of the nation's 11 time zones. State TV showed footage of extensive festive fireworks in cities of the Far East.
But one holiday tradition was missing in Moscow this year — a picturesque layer of snow. The Russian capital has had an unusually warm December and temperatures in central Moscow as midnight approached were just above freezing.
— Associated Press
Pope frees hand from woman's grasp in St. Peter's Square
delighted tourists and Romans in St. Peter's Square on Tuesday night when he took a stroll to admire the Nativity scene. Shouts of "Pope! Pope!" and "Happy New Year!" resounded as families rushed to catch a glimpse of him or thrust out their infant in hopes he would pat their heads or pinch their cheeks.
One woman grabbed the pope's hand and pulled him toward her to shake it. Francis, 83, exclaimed and then struck the woman's hand twice to free his hand.
At a New Year's Eve Vespers service in St. Peter's Basilica, Francis urged people to practice more solidarity and to "build bridges, not walls." Since becoming pontiff in 2013, Francis has preached openness — a reform-minded agenda that has irritated a small but vocal group of ultra-conservatives in the church.
— Associated Press
Rain soaks revelers in Indonesia's capital
Tens of thousands of revelers in Indonesia's capital of Jakarta were soaked by torrential rain as they waited for New Year's Eve fireworks. Festive events along coastal areas near the Sunda Strait were dampened by a possible eruption of Anak Krakatau, an island volcano that erupted in 2018 just ahead of Christmas Day, triggering a tsunami that.
The country's volcanology agency warned locals and tourists to stay 1.3 miles from the volcano's crater following an eruption Tuesday that blasted ash and debris up to 6,560 feet into the air.
— Associated Press
Hong Kong protesters carry demands into 2020
Pro-democracy protesters in Hong Kong held hands and formed human chains across the city on Tuesday. They carried their months-long movement and its demands into 2020 with midnight countdown rallies and a massive march planned for New Year's Day.
The financial hub has been battered by more than six months of unrest that has seen peaceful marches attended by millions as well as violent confrontations in which police have fired tear gas and rubber bullets — and protesters responding with flurries of petrol bombs.
As the final day of the year drew to a close, police used water cannons to disperse small crowds of protesters gathering in the city's Mong Kok district while in nearby Prince Edward neighborhood officers arrested several protesters staging a candlelight vigil.
Earlier, thousands of people linked arms in human chains that stretched for miles along busy shopping streets and through local neighborhoods. They chanted slogans, sang "Glory to Hong Kong" — a symbolic protest anthem — and held up posters calling for people to fight for democracy in 2020.
Celebrating the new year with prayers in Japan
People flocked to temples and shrines in Japan, offering incense with their prayers to celebrate the passing of a year and the first New Year's of the Reiwa era. Under Japan's old-style calendar, linked to emperors' rules, Reiwa started in May, after Emperor Akihito stepped down and his sonbecame emperor.
Although Reiwa is entering its second year with 2020, January 1 still marks Reiwa's first New Year's, the most important holiday in Japan. Stalls at Zojoji Temple in Tokyo sold sweet rice wine, fried noodles and candied apples as well as little amulets in the shape of mice, the zodiac animal for 2020.
Since the Year of the Mouse starts off the Asian zodiac, it's associated with starting anew. Tokyo will host the 2020 Summer Olympics, an event that is creating much anticipation for the entire nation.
— Associated Press
New Zealand bids a rough year farewell
New Zealand's major cities greeted the new year with traditional fireworks. In Auckland, half a ton of fireworks burst from the Sky Tower above the city center.
New Zealanders saw off the old year without regret.
On March 15, a lone gunmanand wounded dozens at two mosques in the South Island city of Christchurch. In December, an off the east coast of the North Island killed at least 19 tourists and tour guides.
- Associated Press
NYC to be "safest place on Earth"
Thein Times Square will be one of the most well-policed, well-protected celebrations on the planet, , as an estimated 1.5 million people prepare to end the 2010s there.
"We call it our Super Bowl," NYPD Counterterrorism Chief Martine Materasso told CBS News correspondent Mola Lenghi. "This is it; this is the big show; this is what we wait for all year long."
Ever since last year's ball drop, the police department has been preparing for this year's decade-ending celebration. Describing the security, Materasso called it "multilayered."
"You will go through numerous steps of screening, from magnetometers to explosive vapor canines," she said, adding revelers out Tuesday night would also see heavy weapons teams.
The chief said nearly the entire department — thousands of officers, both in uniform and in plainclothes — would help secure Times Square with forces on the ground and in the sky.
Sydney fireworks go on despite bush fires
Sydney, Australia, rang in the new year with its world-renowned fireworks, but as the country also faces an unprecedented wildfire crisis, many had at all. The city had to get an exemption from the total fire ban to hold the fireworks show.
Australia Prime Minister Scott Morrison said he supports the decision to go ahead with the fireworks, saying the event shows his country's resilience, reports CBS News correspondent Ian Lee.
Other supporters cited the money it generates for the economy, but thousands disagree. Amid the country's worst wildfire seasons ever, more than 275,000 people signed a petition to cancel the show, saying cities like Sydney that are already choking in smog from fires didn't need any more smoke in its air.
The petition also asked that the millions being spent on the fireworks should have gone toward the army of firefighters battling the flames that have destroyed 1,000 homes and to protect some of the country's devastated wildlife, like some koalas who may have already lost up to 30% of their habitat.
First countries to celebrate New Year 2020: Tonga, Samoa and Kiribati
The Pacific island nations of Tonga, Samoa and Kiribati were the first countries to welcome the new decade. Kiribati's 3,200 coral atolls are strewn over more than 3 million square miles, straddling the equator.
As the new year begins, Kiribati finds itself on the front line of the battle against climate change, facing drought and rising sea levels.
In 2020, a project funded by the World Bank, Asian Development Bank, Green Climate Fund and Kiribati's government brings hope of providing safe and climate-secure drinking water to the main island of Tarawa, which is home to most of the nation's 110,000 people.
- CBS/Associated Press