Saving the ozone layer drastically reduced climate change effects

Saving the ozone layer drastically reduced climate change effects
A new study estimates that the international pledge to save the ozone layer has lessened the effects of climate change
A new study estimates that the international pledge to save the ozone layer has lessened the effects of climate change
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A new study estimates that the international pledge to save the ozone layer has lessened the effects of climate change
A new study estimates that the international pledge to save the ozone layer has lessened the effects of climate change

With so many dire reports coming out about the state of the climate, it’s easy to feel hopeless. But humanity has shown in the past that we can come together to solve seemingly insurmountable environmental problems. The Montreal Protocol in the 1980s has allowed the ozone layer to recover, and now scientists have found that it had another benefit – it’s already slowed climate change by as much as 25 percent.

High in the atmosphere, the ozone layer helps keep Earth habitable by reflecting away the worst of the Sun’s damaging radiation. But in the mid-1980s, scientists discovered a massive hole in this layer over Antarctica. Within a few years, almost 200 United Nations countries signed the Montreal Protocol banning the use of chlorofluorocarbons (CFCs), which were pinned as the culprit.

Now, with the ozone layer hole shrinking rapidly 30 years on, this is often heralded as a success story for global environmental action. And according to a new study from the University of New South Wales (UNSW), the outcome may be even better than we thought.

The researchers modeled the global climate using two different scenarios – one with the Montreal Protocol being enacted, and one without. These covered the period from when it was enacted in the 80s to now, and projected into the future using a conservative estimate of 3 percent growth per year.

The team found that many measures of climate change were significantly better off under the Montreal Protocol than they would have been under a business-as-usual scenario. The average global temperature is set to be at least 1° C (1.8° F) cooler by mid-century than it would have been otherwise, and that figure rises to between 3° and 4° C (5.4° and 7.2° F) in the Arctic.

“By mass CFCs are thousands of times more potent a greenhouse gas compared to CO2, so the Montreal Protocol not only saved the ozone layer but it also mitigated a substantial fraction of global warming,” says Rishav Goyal, lead author of the study. “Remarkably, the Protocol has had a far greater impact on global warming than the Kyoto Agreement, which was specifically designed to reduce greenhouse gases. Action taken as part of the Kyoto Agreement will only reduce temperatures by 0.12° C (0.22° F) by the middle of the century – compared to a full 1° C of mitigation from the Montreal Protocol.”

It’s not just plain surface temperatures either – the Montreal Protocol has lessened the negative run-on effects of climate change too. Arctic summer sea ice extent is estimated to be about 25 percent higher today than it would be otherwise. The melting of Greenland’s ice sheet and sea level rise are also happening slower thanks to the Protocol.

It’s easy to look at climate change as too big a problem for us to solve, but this study gives us renewed hope. It will require unprecedented changes to all aspects of society – but that is achievable if we act sooner rather than later.

“The success of the Montreal Protocol demonstrates superbly that international treaties to limit greenhouse gas emissions really do work,” says Matthew England, co-author of the study. “They can impact our climate in very favorable ways, and they can help us avoid dangerous levels of climate change. Montreal sorted out CFCs, the next big target has to be zeroing out our emissions of carbon dioxide.”

The research was published in the journal Environmental Research Letters. The team describes the work in the video below.

Closing the ozone hole

Source: ARC Centre of Excellence

I'm going to express my skepticism about these "projections" that seem to be made by the people that promised palm trees to be growing on Antarctica by now.
Robert in Vancouver
Scientists just realized ozone has something to do with climate change. Hmmm, so the science isn't settled after all.

(Of course the science isn't settled, real science is never settled which is why the theory of gravity is still being debated.)
Jerome Morley Larson Sr eAIA
That one could feel the effects of depleted ozone on the skin as far north as NYC probably had a lot to do with the urgency to fix the problem — nice having good news for a change.
Robert Bissett
These days you have to double check everything. Google "ozone hole scam heller". Should be the first link. Be sure to read the comments, too.
Douglas Rogers
The Rio Accord got rid of CFC's. The Montreal Protocol got rid of HCFC's. There was a lot of non compliance in Southeast Asia. The culprit was chlorine monoxide, produced when chlorine reacted with excited oxygen, using polar stratospheric clouds as a catalytic bed. This would only produce an ozone reduction in the presence of polar stratospheric clouds. It was never clear that HCFC could transport chlorine into the stratosphere.
Chris Chammas
How the heck do they model such a ridiculously complex system? This is total garbage science and you can easily sniff the BS out when they make the comment “see... global treaties and policy do work to reduce climate change!!” This grift Science needs to be rooted out and people need to be held accountable