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While the news on climate change gets worse, the news on the ozone layer is getting better - the ozone hole above the Antarctic has shrunk.
At about 25 million square kilometres, the hole is the smallest it is been in five years.
It is more than a decade since many of the chemicals that deplete ozone were phased out internationally, but the ozone hole is not likely to completely close just yet.
Dr Paul Fraser is from CSIRO's Marine and Atmospheric Research division. He says while scientists believe the hole is shrinking, its size does vary from year to year.
"The biggest driver of the year-to-year variability in the ozone hole are stratospheric temperatures, and this was a particularly warm year in the stratosphere," he said.
"When you have a warm stratosphere, the processes that destroy ozone in conjunction with the CFCs (chloro fluoro carbon) are much less efficient, and so you end up with a relatively small ozone hole.
"So the year to year variability is determined by the temperature changes, but they're superimposed on a long-term trend and we think that's heading in the right direction towards eventual ozone recovery, but that's going to take a long time."
He says the fact that CFCs (ozone depleting substances) were phased out has helped the situation.
"What's happening is the concentrations of those chemicals under the phase-out peaked in the late 1990s and have been declining ever since at about 1 per cent per year," he said.
"All other factors being equal, we would expect an equivalent response in the ozone hole, so a slow, long-term decline in the depth and the area of the ozone hole."
He says the effects of the CFCs will linger for a long time.
"The ozone depleting chemicals are some of the longest lived chemicals in the atmosphere - on average, typically 100 years or so," he said.
"In effect, we're paying for past sins in the sense that the ozone-depleting chemicals are already in the atmosphere, they're slowly leaking into the stratosphere where they're destroyed, and that's what's causing these ozone holes.
"And until the atmosphere eventually cleanses itself to get rid of these ozone depleting chemicals, then we will continue to have significant ozone depletion."
Climate change
Dr Fraser says global warming will slow the closing process.
"Ozone depleting is temperature sensitive," he said.
"Along with the well-known phenomenon of global warming, that is a warming at the earth's surface as we increase the concentrations of greenhouse gases in the atmosphere, there is another phenomenon occurring, which is stratospheric or upper atmospheric cooling.
"So you have a warming of the surface and a cooling in the stratosphere, so as we head for global warming and stratospheric cooling, we're actually going to have a more efficient ozone depletion process.
"And that acts to counter the loss of ozone depleting chemicals from the atmosphere.
"But nevertheless, if we remove the ozone depleting chemicals from the atmosphere, we will get ozone recovery but it will be delayed by greenhouse warming."
While the news on climate change gets worse, the news on the ozone layer is getting better - the ozone hole above the Antarctic has shrunk.
At about 25 million square kilometres, the hole is the smallest it is been in five years.
It is more than a decade since many of the chemicals that deplete ozone were phased out internationally, but the ozone hole is not likely to completely close just yet.
Dr Paul Fraser is from CSIRO's Marine and Atmospheric Research division. He says while scientists believe the hole is shrinking, its size does vary from year to year.
"The biggest driver of the year-to-year variability in the ozone hole are stratospheric temperatures, and this was a particularly warm year in the stratosphere," he said.
"When you have a warm stratosphere, the processes that destroy ozone in conjunction with the CFCs (chloro fluoro carbon) are much less efficient, and so you end up with a relatively small ozone hole.
"So the year to year variability is determined by the temperature changes, but they're superimposed on a long-term trend and we think that's heading in the right direction towards eventual ozone recovery, but that's going to take a long time."
He says the fact that CFCs (ozone depleting substances) were phased out has helped the situation.
"What's happening is the concentrations of those chemicals under the phase-out peaked in the late 1990s and have been declining ever since at about 1 per cent per year," he said.
"All other factors being equal, we would expect an equivalent response in the ozone hole, so a slow, long-term decline in the depth and the area of the ozone hole."
He says the effects of the CFCs will linger for a long time.
"The ozone depleting chemicals are some of the longest lived chemicals in the atmosphere - on average, typically 100 years or so," he said.
"In effect, we're paying for past sins in the sense that the ozone-depleting chemicals are already in the atmosphere, they're slowly leaking into the stratosphere where they're destroyed, and that's what's causing these ozone holes.
"And until the atmosphere eventually cleanses itself to get rid of these ozone depleting chemicals, then we will continue to have significant ozone depletion."
Climate change
Dr Fraser says global warming will slow the closing process.
"Ozone depleting is temperature sensitive," he said.
"Along with the well-known phenomenon of global warming, that is a warming at the earth's surface as we increase the concentrations of greenhouse gases in the atmosphere, there is another phenomenon occurring, which is stratospheric or upper atmospheric cooling.
"So you have a warming of the surface and a cooling in the stratosphere, so as we head for global warming and stratospheric cooling, we're actually going to have a more efficient ozone depletion process.
"And that acts to counter the loss of ozone depleting chemicals from the atmosphere.
"But nevertheless, if we remove the ozone depleting chemicals from the atmosphere, we will get ozone recovery but it will be delayed by greenhouse warming."
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