(NEW YORK) — Carbon dioxide may be a naturally occurring substance on Earth, but too much of its presence has contributed to global warming, climate scientists say.
Carbon dioxide, known by the chemical formula CO2, is a gas produced by various natural processes, including respiration in animals and plants, volcanic eruptions, wildfires and the decay of organic matter.
But human activity since the 1800s, namely the use of fossil fuels for energy, is overwhelming the planet’s natural carbon sinks, such as oceans and forests. Therefore, the heat-trapping gas causes global temperatures to rise as more of it accumulates in the Earth’s atmosphere.
“CO2 is rising right now because of the emissions that we’re putting into the atmosphere, and it’s rising very rapidly,” Bärbel Hönisch, professor of earth and environmental sciences at the Columbia Climate School’s Lamont-Doherty Earth Observatory, told ABC News. “And carbon dioxide is a greenhouse gas, and so it heats the atmosphere.”
But the invisible gas is also critical for life on Earth. Plants breathe it in, and humans breathe it out.
The goal of climate mitigation isn’t to remove CO2 from the atmosphere completely, but to even out the unnatural surplus instead, said ABC News Chief Meteorologist and Chief Climate Correspondent Ginger Zee.
“We want to get back to the natural amount of CO2,” Zee said.
The consequences of extra CO2 in the atmosphere extends beyond the climate itself. As excess greenhouse gases heat the planet, the ocean becomes more acidic, impacting marine life, Hönisch said. In addition, climate change is fueling rapid growth of certain types of algae, further collapsing ecosystems, Hönisch added.
“Climate is a combination of different components that must be just right for life to exist on our planet,” she said.
Humans have injected more than 1.5 trillion tons of CO2 into the atmosphere since the Industrial Revolution, when the use of fossils fuels began to skyrocket, according to the Global Carbon Budget.
Historical levels of climate change are determined by a number of processes. Samples of ice, lake and seafloor cores indicate how much carbon dioxide existed at different periods on the planet. In addition, more than six decades of CO2 measurements have been taken at the Mau Loa Observatory on Hawaii’s Big Island, home to the largest active volcano in the world.
The Keeling Curve, a graph that plots concentrations of CO2 in the atmosphere over time, uses measurements taken at Mau Loa Observatory, starting in 1958.
In 2024, CO2 levels in Earth’s atmosphere reached the highest ever recorded, according to the National Oceanic and Atmospheric Administration.
Curbing the emissions of greenhouse gases from fossil fuel use is key for limiting the impacts of a warming world, such as more frequent and intense extreme weather events and rising sea levels, climate scientists say.
(WASHINGTON) — All imports of live cattle, horse and bison from the southern border have been banned due to the spread of a flesh-eating pest in Mexico, the U.S. Department of Agriculture (USDA) said on Sunday.
“The protection of our animals and safety of our nation’s food supply is a national security issue of the utmost importance,” USDA Secretary Brooke Rollins said in a press release.
The secretary cited New World Screwworm (NWS), a parasitic fly, as the reason for the suspension of imports. The name refers to the way in which maggots screw themselves into the tissue of animals with their sharp mouth hooks, causing extensive damage and often leading to death.
Panama saw NWS infections among livestock rise from an average of 25 cases annually to over 6,500 in 2023. Since then, the disease has spread further north, breaking a previously established barrier that contained the pest to South America for decades, the USDA said.
Infections have been detected in Costa Rica, Nicaragua, Honduras, Guatemala, El Salvador and Belize.
More recently, a case was reported in Mexico late last year, which also shut down the border for live animal trade. Imports resumed earlier this year after an agreement between the U.S. and Mexico to mitigate the threat of the disease.
The continued spread and threat of NWS led to the current shutdown, which will continue on a month-by-month basis, “until a significant window of containment is achieved,” the USDA said. The disease was recently detected in remote farms about 700 miles from the U.S. border.
Eradicating the disease is possible through a technique in which male screwworm flies are sterilized and then released into the environment to mate with females until the population dies out. This process was used to rid the U.S. of NWS in the 1960s.
The eradication efforts yielded estimated economic benefits of nearly $800 million annually for American livestock producers in 1996, with an estimated $2.8 billion for the wider economy, according to the USDA.
U.S. agriculture officials are working to release sterile flies by both air and ground along parts of Southern Mexico and in other regions in Central America.
“Once we see increased surveillance and eradication efforts, and the positive results of those actions, we remain committed to opening the border for livestock trade,” Rollins said. “This is not about politics or punishment of Mexico, rather it is about food and animal safety.”
(STARKVILLE, MS) — Geologists working in Mississippi recently stumbled upon an incredible find: the fossil of an ancient marine apex predator.
They uncovered a piece of vertebra they said likely belonged to a mosasaur, a lizard ancestor that lived in the Late Cretaceous period, according to James Starnes, research director for the surface geology and surface mapping divisions for the Mississippi Department of Environmental Quality.
On April 15, researchers were collecting rock, sediment and fossil samples just south of Starkville, Mississippi, Starnes said. Poking out from the sediment of a creek bed was the end an “unusually large” lumbar vertebra.
After Starnes pointed it out, Jonathan Leard, the lead author of the MDEQ’s geological map, pulled the vertebra out of the clay.
“Both of us are standing there looking at each other with our jaws wide open because of the size,” Starnes said.
Starnes “immediately” knew they had found a mosasaur based on the shape of the vertebra, he said. The researchers estimated the specimen, determined to be Mosasaurus hoffmannii, was between 30 and 40 feet long when it died, but mosasaurs typically grew to be about 50 feet and weighed 20,000 pounds.
“These animals, like other lizards, are indeterminate,” Starnes said. “That means they just keep growing, with age, until they die.”
Due to its geological formations, the Mississippi region is known for its fossils, but this was especially rare, Starnes said.
Shell fossils are common, as are much younger Ice Age fossils from land animals, such as mastodons and sloths. But mosasaurs have a “very different” vertebra shape than other animals.
“This was distinctly not a mammal,” Starnes said. “This was definitely a sea lizard.”
Mosasaurs, a diverse group of marine lizards, conquered the seas in the Late Cretaceous period, a time when dinosaurs inhabited various ocean environments.
The Mississippi River occupies an ancient geologic structure called the Mississippi Embayment, which was inundated by the Western Interior Sea Way during the Cretaceous period.
Mosasaur fossils have been found in the area before, but only in much smaller fragments, Starnes noted. This was the largest mosasaur fossil the researchers had ever encountered.
Mosasaurs were fast and agile swimmers with jaws that contained 60 dagger-like teeth that helped them capture large prey, researchers said.
Scientists believe mosasaurs became extinct at the end of the Cretaceous period, according to Mississippi Department of Environmental Quality researchers.
(VATICAN CITY) — Pope Francis has been laid to rest, the conclave has been assembled and, after due deliberation by the participating cardinals, the world at last has seen white smoke wafting from the Sistine Chapel chimney, signaling that a new pope has been elected.
So, what happens next?
There have been just seven papal elections in the last 100 years, with more than a quarter-century passing between the election of Pope John Paul II in October 1978 and that of his successor, Benedict XVI, in April 2005. And now as then, longstanding tradition dictates both the practical and ceremonial steps that occur between the new pontiff’s election and when he is officially installed as the leader of the world Catholic Church.
While it can take days, weeks or longer for the cardinals comprising the conclave to reach the two-thirds majority required to elect a new pope – the record is 1,006 days, set in the 13th century – once the election is over, the subsequent events transpire with impressive speed.
Countdown to first public appearance
The first announcement to the world that a new pope has been selected is signaled per tradition by ringing the bells as St. Peter’s Basilica as white smoke – fumata bianca – issues from the stovepipe chimney atop the Sistine Chapel. With those ceremonial notices, an informal countdown begins to the moment that the new pope’s identity is revealed to the world.
While the faithful typically congregate in St. Peter’s Square daily during the conclave, the public signal that a pontiff has been chosen precipitates a surge of observers rushing to be among the first to see the new pope in person.
Although much ceremony remains, it’s important to note that the newly elected pope’s full authority and jurisdiction begins immediately upon his acceptance of the office, which he of course must do before any public announcement – if he refuses the office, the conclave continues the balloting.
As soon as the new pontiff has assented to his election the conclave ends, though the assembled cardinals will remain at the Vatican until the attendant ceremonies are over. In 2013, Francis requested that the cardinals remain in Rome for an extra day to pray with him.
Meanwhile, the new pope is formally asked by what name he will be known. While popes aren’t obliged to change their name, every pontiff for the past 470 years has done so, usually choosing the name of a predecessor to both honor them and signal their intention to emulate his example. Pope Francis was a notable exception, choosing not the name of a former pope but that of St. Francis of Assisi, the 13th century cleric and patron saint of animals and the environment.
The only pontifical name that hasn’t been used more than once is Peter, the name of the first pope, though there’s no prohibition against doing so.
Papal clothing for his first appearance
The next step is to get the new pope attired for his first public appearance. The liturgical garments – such as robes, stoles and hats – worn by the pope and other Christian church officials are known as vestments. Since 1798, the pope’s vestments have been manufactured by the Gammarelli family tailors in Rome, who first made the garments for Pope Pius VI. This year, however, ecclesiastical tailor Ranieri Manchinelli, also in Rome, has prepared the new pope’s vestments.
Since no one knows who will be elected pope – and therefore, what size clothing the new pope will require – three sets of vestments are prepared ahead of time for his first public appearance, in sizes small, medium and large.
The vestments are placed in the Stanza delle Lacrime, or Room of Tears, which is a small sacristy, or clergy preparation area, just off the Sistine Chapel. It’s here that the new pope will dress in his temporary vestments as the world awaits his first public appearance. However, there’s still a final bit of ceremony to complete.
The Fisherman’s Ring
Once attired in his vestments, the pontiff returns to the Sistine Chapel and sits on a papal chair. The camerlengo – that is, the cardinal who oversees the conclave, in this case Cardinal Kevin Ferrell – then escorts the master of ceremonies who bears the Fisherman’s Ring on a velvet cushion to the new pope. Pope Francis’ ring was ceremonially broken after his death – a ritual signifying the formal end of his papal authority and marking the transition of leadership and the close of his chapter in Church history.
Perhaps more than any other item, the Fisherman’s Ring in popular culture is most closely identified with papal authority. So named in honor of St. Peter the Apostle, a fisherman and the first pope, Catholics who meet the pope traditionally kiss the ring to demonstrate both their respect for the pontiff and their devotion to the Church.
The camerlengo places the Fisherman’s Ring on the fourth finger of the pope’s right hand, then kneels and kisses it. The pope then removes the ring and gives it to the master of ceremonies, who will have the new pope’s name inscribed on it.
The assembled cardinals next step up in turn and pay homage to the new pope, who leads them in a hymn and also gives them his benediction – the first blessing of his pontificate.
‘Habemus papam’
Now fittingly attired in his temporary vestments, the new pope enters St. Peter’s Basilica for the formal announcement of his election and the revelation of his identity to the faithful and the world.
With thousands gathered in St. Peter’s Square below, the attendant cardinals first emerge onto the side balconies of the St. Peter’s Basilica facade. The senior cardinal deacon then appears on the central balcony and declares in Latin: “Nuntio vobis gaudium magnum: Habemus papam” – “I announce to you a great joy: We have a pope.”
The senior cardinal deacon then announces both the birth name of the elected cardinal, and the pontifical name the new pope has chosen for himself.
It is only now – typically a mere hour or so after the white smoke first emerged from the stovepipe chimney of the Sistine Chapel – that the new pope, clad in his papal vestments, steps out onto the balcony and greets the world. He immediately delivers his first Apostolic Urbi et Orbi blessing – meaning to “the city and the world.”
Formal installation in office
A ceremonial mass to formally install the new pope is held about a week after his election, either in St. Peter’s Square or basilica, with cardinals, bishops and other international dignitaries present. While the ceremony historically featured far more pomp and pageantry akin to a coronation – including the pope being literally crowned with a triregnum, or three-tiered tiara, and sitting on an ornate papal throne – much of that pageantry has been abandoned.
Pope Paul VI was the last to wear the triregnum, during his installation in 1963. He also was the first to hold the ceremony outdoors, in St. Peter’s Square, to accommodate the enormous crowds that wished to attend.
ABC News’ Phoebe Natanson contributed to this report.
