International cooperation on ozone-depleting chemicals is helping to return the southern jet stream to a normal state after decades of disruption, a study shows.
Scientists say the findings prove that there is the capacity to heal damaged climate systems if governments act promptly and in coordination to deal with the causes.
The southern jet stream is a powerful wind that shapes weather patterns and ocean currents in the southern hemisphere, particularly in the summer.
Up until about 2000, it had been shifting from its usual course and moving southward at a rate of 1° of latitude each decade, affecting storm tracks and rainfall over South America, east Africa and Australia.
Previous research has shown this was primarily driven by the depletion of the ozone layer by chemical compounds such as chlorofluorocarbons and hydrochlorofluorocarbons, which are found in fridges, aerosols and other industrial processes.
The chemicals, which were used in vast quantities until they started to be phased out under the UN 1987 Montreal Protocol, thinned the ozone layer, causing a widening “hole” high above the south pole that affected wind patterns.
The paper, published in the journal Nature, shows that the Montreal Protocol has paused the southward movement of the jet stream since the turn of the century and might even be starting to reverse it as the ozone hole begins to close.
In September last year, satellite images showed that the ozone hole annual peak had shrunk to 16.4 million square kilometers, the smallest extent since 1982.
“It’s a success story. This is more evidence that the Montreal Protocol has led to the recovery of the ozone layer,” said the study’s lead author, Antara Banerjee, who works in the chemical sciences division of the US National Oceanic and Atmospheric Administration and is a visiting fellow at the University of Boulder, Colorado.
The expected effect on people will vary from region to region. In Patagonia in southern Chile and Argentina, there should be more rain and less ultraviolet light.
The findings will be of more concern for Uruguay, Paraguay, southern Brazil and northern Argentina, where ozone depletion was previously found to bring more rainfall and wider bands of agricultural production.
Previous studies suggest the reversal might also be good news for Australia, which has had more droughts because the jet stream pushed rain-bearing storms away from its coast during winter.
A coronavirus-free tropical island nestled in the northern Pacific might seem the perfect place to ride out a pandemic, but residents on Palau said that life right now is far from idyllic. The microstate of 18,000 people is among a dwindling number of places on Earth that still report zero cases of COVID-19 as figures mount daily elsewhere. The disparate group also includes Samoa, Turkmenistan, North Korea and bases on the frozen continent of Antarctica. A dot in the ocean hundreds of kilometers from its nearest neighbors, Palau is surrounded by the vast Pacific Ocean, which has acted as a buffer against the
Dutch scientists have found the coronavirus in a city’s wastewater before COVID-19 cases were reported, demonstrating a novel early warning system for the disease. SARS-CoV-2 — the virus that causes COVID-19 — is often excreted in an infected person’s stool. Although it is unlikely that sewage will become an important route of transmission, the pathogen’s increasing circulation in communities would increase the amount of it flowing into sewer systems, Gertjan Medema and colleagues at the KWR Water Research Institute in Nieuwegein said on Monday. They detected genetic material from the coronavirus at a wastewater treatment plant in Amersfoort on March 5, before
‘LIKE A CASSANDRA’: Chinese residents of Prato went into self-imposed lockdown and warned their Italian neighbors about what was coming, but were ignored In the storm of infection and death sweeping Italy, one big community stands out to health officials as remarkably unscathed — the 50,000 ethnic Chinese who live in the town of Prato. Two months ago, the country’s Chinese residents were the target of what Amnesty International described as shameful discrimination, the butt of insults and violent attacks by people who feared that they would spread the coronavirus through Italy. However, in the Tuscan town of Prato, home to Italy’s single biggest Chinese community, the opposite has been true. Once scapegoats, they are now held up by authorities as a model for early,
TRUE TOLL? Some Chinese are skeptical about official data, particularly given the overwhelmed medical system and initial attempts to cover up the outbreak The long lines and stacks of urns greeting family members of the dead at funeral homes in Wuhan, China, are spurring questions about the true scale of casualties at the epicenter of the COVID-19 outbreak, renewing pressure on a Chinese government struggling to control its containment narrative. The families of those who succumbed to the coronavirus in the city, where the disease first emerged, were allowed to pick up their cremated ashes at eight funeral homes last week. As they did, photographs circulated on Chinese social media of thousands of urns being ferried in. Outside one funeral home, trucks shipped in about 2,500