The ozone layer protects life on earth from harmful levels of ultraviolet rays from the sun.
This is due to internationally agreed actions carried out under the historic Montreal Protocol, which came into being over 30 years ago.
It is possible the healing of the ozone hole above Antarctica may insulate the continent and accelerate climate warming, but report co-author Ross Salawitch, an atmospheric scientist at the University of MI, said the immediate effects of ozone damage were such that it would be "incredibly irresponsible" not to protect the depleted ozone layer.
"We're raising a flag to the global community to say, 'This is what's going on, and it is taking us away from timely recovery of the ozone layer, '" NOAA scientist Stephen Montzka, the study's lead author, said in a statement at the time.
Monday's report says the Northern Hemisphere's upper ozone layer should be repaired in the 2030s and the Southern Hemisphere's by mid-century.
"It's really good news", said report co-chairman Paul Newman, chief Earth scientist at NASA's Goddard Space Flight Center.
"The Montreal protocol is one of the most successful multilateral agreements in history for a reason", said Erik Solheim, head of UN Environment. Scientist raised the alarm and ozone-depleting chemicals were phased out worldwide.
The report also said it was the first time the hole in the ozone layer had shrunk in both size and depth and size since 2000.
The report said the source country or countries had not yet been identified.
A United Nations study has revealed that the ozone layer is slowly recovering, and is even expected to be fully repaired by the 2060s.
However, the report did note there is evidence of an increase in CFC-11 - an ozone depleting chemical - from eastern Asia since 2012.
Experts credit a 1987 treaty that banned ozone-depleting chemicals, as well as new technology, for the global environmental success story. And the Montreal Protocol is set to be enhanced in early 2019 with the ratification of the Kigali Amendment, which seeks to curb future climate change by targeting powerful greenhouse gases used in refrigeration and air conditioning.
Mr Newman added: "I don't think we can do a victory lap until 2060, ' he said".
"The careful mix of authoritative science and collaborative action that has defined the Protocol for more than 30 years and was set to heal our ozone layer is precisely why the Kigali Amendment holds such promise for climate action in future", he said.