Stephen Montzka and colleagues at the US National Oceanic and Atmospheric Administration (NOAA) looked at levels of CFC-11 in the atmosphere using measurements taken at the Mauna Loa Observatory in Hawaii. "In fact, I was amazed by this".
When a hole in the ozone formed over Antarctica, countries around the world in 1987 agreed to phase out several types of ozone-depleting chemicals called chlorofluorocarbons. Since 2006, countries have reported close to zero production of CFC11. However, in 1987, an worldwide team of scientists proved that the emissions of such chemicals were actually harming the environment, particularly the ozone layer.
The ozone layer is crucial for sustaining life on Earth.
Their results indicate that emissions of trichlorofluoromethane - known as CFC-11 - are increasing, suggesting it is still being produced and used despite a ban on manufacturing it after 2010.
L'impact de la pollution pendant la grossesse coûte 1,2 milliard d'euros
Ils recommandent donc de limiter les déplacements des femmes enceintes lors des pics de pollution. La prise en charge du handicap de ces enfants a un coût pour la société et pour leur famille.
Despite the resistance to fighting climate change that we still have to deal with, some aspects of our planet are improving due to global efforts to reduce our impact - namely, the ozone layer is finally reforming.
"The newer substances that are out there, the replacements for CFC-11, might be more hard or expensive for some countries to produce or get at".
While the new analysis can't definitively explain why emissions of CFC11 are increasing, but Montzka suspects covert production. Pictured, the Antarctic ozone hole, located above the South Pole. It is thought that about 13,000 tonnes a year has been released since 2013.
CFC-11 still contributes about a quarter of all chlorine - the chemical that triggers the breakdown of ozone - reaching the stratosphere.
Iran diplomat visits China for talks on nuclear deal crisis
Kim Jong Un will demand a lot more from us than he might have just to show we'll honor any deal with him. Mohammad Ali Jafari, head of the Revolutionary Guards, said the country could not rely on the West.
"A timely recovery of the stratospheric ozone layer depends on a sustained decline of CFC-11 concentrations", the wrote.
"I hope that somehow the global community can put pressure on South East Asian countries, maybe China, to go and look at whether they can get more information on where the emissions come from".
Keith Weller, a spokesman for the United Nations Environment Program, which helps implement the protocol, said the findings would be presented to the parties to the agreement for review. The researchers have said they would need more measurements to figure the exact location of the source and take necessary action. "They should tell the industries that's not going to work". This insults everybody who's worked on this for the last 30 years. But the researchers noticed the rate at which it is declining appeared to be slowing down.
But in 2012 scientists noted that the rate of decline had slowed by 50 per cent, according to the new study. This, in turn, will delay the ozone layer's recovery, and in the meantime leave it more vulnerable to other threats. Though concentrations of CFC11 in the atmosphere are still declining, they're declining more slowly than they would if there were no new sources, Montzka said.
Officiel - West Ham et David Moyes se séparent
Il était arrivé au London Stadium en novembre avec pour seul objectif d'assurer le maintien en Premier League des Hammers. Selon le dirigeant anglais, le club nommera un successeur dans "les dix prochains jours" .