S Africa celebrates 'mother of the nation' Winnie, after her death at 81

Kensington (United States), May 20: The world cut its daily carbon dioxide emissions by 17% at the peak of the pandemic shutdown last month, a new study found.

But with life and heat-trapping gas levels inching back toward normal, the brief pollution break will likely be “a drop in the ocean" when it comes to climate change, scientists said.

In their study of carbon dioxide emissions during the coronavirus pandemic, an international team of scientists calculated that pollution levels are heading back up — and for the year will end up between 4% and 7% lower than 2019 levels.

That's still the biggest annual drop in carbon emissions since World War II.

It'll be 7% if the strictest lockdown rules remain all year long across much of the globe, 4% if they are lifted soon.

For a week in April, the United States cut its carbon dioxide levels by about one-third.

China, the world's biggest emitter of heat-trapping gases, sliced its carbon pollution by nearly a quarter in February, according to a study Tuesday in the journal Nature Climate Change. India and Europe cut emissions by 26% and 27% respectively.

The biggest global drop was from April 4 through 9 when the world was spewing 18.7 million tons (17 million metric tons) of carbon pollution a day less than it was doing on New Year's Day.

Such low global emission levels haven't been recorded since 2006. But if the world returns to its slowly increasing pollution levels next year, the temporary reduction amounts to ''a drop in the ocean," said study lead author Corinne LeQuere, a climate scientist at the University of East Anglia.

“It's like you have a bath filled with water and you're turning off the tap for 10 seconds," she said.

By April 30, the world carbon pollution levels had grown by 3.3 million tons (3 million metric tons) a day from its low point earlier in the month. Carbon dioxide stays in the air for about a century.

Outside experts praised the study as the most comprehensive yet, saying it shows how much effort is needed to prevent dangerous levels of further global warming.

“That underscores a simple truth: Individual behavior alone ... won't get us there,” Pennsylvania State University climate scientist Michael Mann, who wasn't part of the study, said in an email.

“We need fundamental structural change.”

If the world could keep up annual emission cuts like this without a pandemic for a couple decades, there's a decent chance Earth can avoid warming another 1.8 degrees (1 degree Celsius) of warming from now, study authors said. But getting the type of yearly cuts to reach that international goal is unlikely, they said.

If next year returns to 2019 pollution levels, it means the world has only bought about a year's delay in hitting the extra 1.8 degrees (1 degree Celsius) of warming that leaders are trying to avoid, LeQuere said. That level could still occur anywhere from 2050 to 2070, the authors said.

The study was carried out by Global Carbon Project, a consortium of international scientists that produces the authoritative annual estimate of carbon dioxide emissions. They looked at 450 databases showing daily energy use and introduced a measurement scale for pandemic-related societal “confinement” in its estimates.

Nearly half the emission reductions came from less transportation pollution, mostly involving cars and trucks, the authors said. By contrast, the study found that drastic reductions in air travel only accounted for 10% of the overall pollution drop.

In the US, the biggest pollution declines were seen in California and Washington with plunges of more than 40%.

Beijing, Mar 24:  China reported 78 new confirmed cases, including 74 imported infections, while the death toll from the novel coronavirus increased to 3,277 after seven more fatalities were confirmed from the COVID-19, health officials said on Tuesday.

The overall confirmed cases on the Chinese mainland have reached 81,171 by the end of Monday. This included 3,277 people who died of the disease, 4,735 patients who were still being treated and 73,159 patients discharged after recovery, the National Health Commission (NHC) said on Tuesday.

The NHC said, 78 new confirmed COVID-19 cases were reported on the Chinese mainland on Monday, of which 74 were imported from abroad taking the number of overseas cases to 427.

Also on Monday, seven deaths and 35 new suspected cases were reported on the mainland with all the deaths in Hubei Province.

The total COVID-19 cases in Beijing climbed to 522 with eight deaths prompting local governments of Beijing as well as Shanghai to announce that all overseas arrivals will be subjected to nucleic acid tests to ensure proper detection.

Of the 74 newly imported cases, 31 were reported in Beijing, 14 in Guangdong, nine in Shanghai, five in Fujian, four in Tianjin, three in Jiangsu, two in Zhejiang and Sichuan respectively, and one in Shanxi, Liaoning, Shandong and Chongqing respectively, the NHC said.

Beijing is already diverting all international flights to different cities where the passengers will be quarantined for 14 days before arriving in the city.

The NHC said 132 people were still suspected of being infected with the virus.

Coronavirus epicentre Wuhan has reported one confirmed case after a gap of five days prompting officials to begin to ease restrictions.

Wuhan also reported seven new deaths, bringing the total number of deaths in the city and Hubei province for which Wuhan is the capital to 3,160.

The province also saw 444 patients discharged from hospital after recovery on Monday. Among the 4,200 patients being treated in hospital, 1,203 were still in severe condition and another 336 in critical condition, the local health commission said.

By the end of Monday, 356 confirmed cases, including four deaths have been reported in Hong Kong, which has restricted the entry of foreigners into the city. Also a total of 25 confirmed cases were reported in Macao and 195 in Taiwan including two deaths, state-run Xinhua news agency reporrted.

After days of decline in coronavirus cases, China on Monday said that COVID-19 has effectively been "stemmed" in the country and it started easing severe restrictions imposed on Wuhan's 11 million people who were under lockdown since January 23.

The authorities began relaxing restrictions in Wuhan as it reported no new case for the fifth consecutive day on Monday.

Significantly, the Central Leading Group (CLP), headed by Premier Li Keqiang which is coordinating efforts to contain the virus since January 23, said the virus has been curtailed in the country as well as in Wuhan.

"The meeting noted that the spread of the virus nationwide, particularly in the epicentre of Wuhan, has been effectively stemmed," an official statement said on Monday.

The meeting, however, warned that the risks for sporadic infections and localised outbreaks have not gone away. With the pandemic rampaging across the world, the situation remains complex and challenging.

"Wuhan city and Hubei province should stay focused on medical treatment and community-level containment as the two key priorities. They should continue to treat the severe cases, promptly admit new cases, and advance epidemiological investigations," the meeting said.

In Wuhan, officials said people are allowed to go back to work while restrictions on the public transport are gradually being eased.

The Hubei province and its capital Wuhan with over 56 million people were under lockdown since January 23. The vicious virus broke out in city, reportedly at a live animal market in December last year and became virulent inflicting thousands of people in the city and province catching the government off guard.

As the country saw a surge in imported infections, the Chinese government announced that all international flights scheduled to arrive in Beijing will be redirected to airports in 12 other Chinese cities from Monday.

International passengers flying to Beijing will instead land at airports in 12 cities including Shanghai, Tianjin, Nanjing and Shenyang as their first points of entry, the Civil Aviation Administration of China (CAAC) said in a statement.

On Monday, China said international travellers should "think twice" about choosing Beijing for flight transfer in view of the restrictions.

Starting from Monday, all international flights scheduled to arrive in Beijing will be redirected to airports in 12 other Chinese cities, Liu Haitao, an official with China's National Immigration Administration said.

Passengers would go through entry procedures and quarantine measures at the designated cities' airports before they continue their flights to Beijing, Liu said, urging travellers to reserve enough time for their next flights to make sure that they do not miss their outbound flights.

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.