Ozone continues to deplete

  Last updated February 7, 2018 at 3:08 pm

Topics:  

The ozone layer that shields us from damaging UV radiation is not recovering at lower latitudes, even though the hole over the Antarctic is healing, and scientists don’t really know why.


Earths atmosphere as seen from space. Credit: NASA.


The Montreal Protocol in 1987 was one of those rare times in human history where we saw a problem and came together to implement a global solution.  The problem was CFCs from aerosols and refrigerants that were chewing through atmospheric ozone.  The Montreal Protocol was an agreement to phase-out the use of CFCs, and was recently lauded as a success by a NASA study using statellite data that showed the ozone hole over Antarctica recovering.


In a new study in Atmospheric Chemistry and Physics, Joanna Haigh from Imperial College London and colleagues analysed data from satellite missions since 1985 to detect a long term trend of decreasing ozone in the stratosphere at lower altitudes and latitudes.


“Th potential for harm in lower latitudes may actually be worse than at the poles.” Says Joanna Haigh, “The decreases in ozone are less than we saw at the poles before the Montreal Protocol was enacted, but UV radiation is more intense in these regions and more people live there”.


Researchers are unsure as to the cause of the decline, but suggest it could be that climate change is changing how ozone circulates in the atmosphere, carrying it away from the equator, or that very short-lived substances containing cholrine and bromine found in solvents and paint-strippers could be destroying ozone in the lower stratosphere.


So what does this mean? Here are reactions from scientists around Australia:


Bill Laurance is a Distinguished Professor at James Cook University


“This study is scary. Until we understand what’s really happening you’d be silly to sun yourself, except in polar regions.


The era of suntanning could be over; we might be entering the age of the unfailing sunburn.”


Ian Lowe is Emeritus professor of science, technology and society at Griffith University and former President of the Australian Conservation Foundation and Bragg member of the Royal Institution of Australia


“The World Scientists’ Warning to Humanity, Second Notice, published in November, noted that only one environmental indicator has significantly improved since 1992.


The amount of ozone-depleting substances has been reduced dramatically, from about 1.5 million tonnes of chlorofluorocarbon (CFC)-equivalent to 0.3 million. It has not been reduced to zero.


The reduction in the rate of release of these chemicals has halted the worsening of ozone depletion, but we are not yet seeing significant repair.


This paper also shows that the system is complicated and there are still aspects we do not understand well enough to model the observed data. It should be another urgent reminder that we must scale back our assault on natural systems if we are to achieve our stated goal of living sustainably.


Since we have known for more than forty years that a group of chemicals weakens the ozone layer, which protects all life from damaging ultra-violet radiation, phasing these chemicals out completely should be a high priority.”


Emeritus Professor Brenton Lewis is from the Research School of Physics and Engineering at The Australian National University


“As stated in conclusion (iv) of the paper, “there is no significant change in total ozone column density between 1998 and 2016“.


Therefore, there will have been no corresponding increase in harmful UV radiation at ground level, and people need not be concerned. The authors are engaged simply with explaining a change in the distribution of ozone in the atmosphere, which may well be due to transport mechanisms only.


This is not to say that continued studies are unnecessary.”


Professor Steven Sherwood is ARC Laureate Fellow at the ARC Centre for Climate System Science and UNSW Climate Change Research Centre


“This finding is very interesting for scientists but I don’t think it has any broader significance yet.


The authors do not call into question the prevailing view that the ozone layer is entering a recovery phase after the damage caused in the 1980’s and 90’s by refrigerant gases, which were phased out by the Montreal Protocol.


They do find a curious ozone decrease in a particular altitude range below the main ozone layer, which suggests that changes to the atmospheric circulation may have happened up there. The community will have to look at this more carefully before we know what it means.”


Professor Ian Rae is a  former President of the Royal Australian Chemical Institute and has been an advisor to the United Nations Environment Programme on chemicals in the environment. Ian is also an editor of the Australian Academy of Science journal, Historical Records of Australian Science


“We know that the worst ozone-depleting substances are chlorofluorocarbons (CFCs) and other volatile chemicals containing chlorine or bromine. Emissions of these substances have been drastically reduced by international agreement, under the Montreal Protocol, to ban or restrict their production and consumption. As a result (we’d like to believe), the decline in the stratospheric ozone concentration has been arrested and there are some signs of recovery.


However, given the steep decline in emissions, we might have expected a better result for the ozone layer. This analysis of research results, published by an international group of scientists, help us to understand why we haven’t. In short, the outcome is a curate’s egg: good in parts.


Measurements of ozone concentration are made for a notional column of air stretching up from about 10 km above earth’s surface to about 50 km. As an aside, it helps to use round numbers to convey the message because there are variations with seasons and with latitude – position on the earth.


For the column as a whole, there has not been much change in ozone concentration during the period 1998-2016. When results for ‘slices’ of the air in that column were examined, a more complex picture emerged. In the upper stratosphere (32-48 km), there has been a steady increase in ozone concentration, which is what was expected from the actions taken under the Montreal Protocol.


However, in a lower slice of the air column(13-24 km), there has been a continuous decline. The reasons for this decline remain unknown. Unlike the positive change at higher levels, this negative is not predicted by models of atmospheric chemistry.


The result of their analysis is nicely summed up by the authors: “We find that the negative ozone trend within the lower stratosphere between 1998 and 2016 is the main reason why a statistically significant recovery in total column ozone has remained elusive.”


In colloquial language: if you add a positive change and a negative change, you get zero change.”


Dr Paul Read is at the Melbourne Sustainable Society Institute at the University of Melbourne


“Although the authors suggest otherwise, this paper could be a challenge to the effectiveness of the Montreal Protocol.


Ozone, like atmospheric carbon, is critical to maintaining the survivability of Earth’s solar budget – all of life depends on them being maintained in a tight range. Ozone we need; too much atmospheric carbon we don’t.


This is because energy from the Sun comes in three types – per kilowatt, 32 watts is ultraviolet (UV), which destroys DNA, 445 watts is visible light, and 526 is infrared, the stuff you feel as heat.


Whereas a thin film of ozone protects us from the DNA scrambling effects of UV, a growing film of carbon emissions lets infrared waves in but then traps them, causing the Greenhouse effect.  As for ozone, most people know that our wholesale use of chlorofluorocarbons (CFCs) amassed in the atmosphere and created a hole in the ozone layer that was then exposing us to cancer-causing UV light.


For fear of skin cancer, Australian beach culture changed overnight – the ‘slip slop slap’ campaign, the invention of rashies, etc. It took a whole world effort to ban CFCs – every country and every industry – and we went, for example, from spray cans to roll-on deodorant pretty quick smart.


The Montreal Protocol banned CFCs and was the world’s first universal agreement to cooperate on behalf of global human health. Kofi Annan said it was a great sign of hope that the world could be civilised enough to do the same for climate change; estimates say it’s already saved many more than 280 million lives.


What this new paper is saying is that the hole in the ozone layer, predicted to be completely repaired by around 2060, has a whole section that’s not repairing itself. And they want to know why!


The section in question is about 20 kms above Earth, between the tops of clouds and the height where aeroplanes cruise, and extends from just outside the Arctic circle to the start of Antarctica.


Even though the polar regions and the higher stratospheric levels of ozone are repairing themselves, this lower, middle section is going in the opposite direction – the amount of ozone is still falling just like it was before the Montreal Protocol.


A million things could be causing this, some natural, some not. But this paper tries with all its might to get around a host of past problems to see the real trend – and the ozone is definitely falling in that region, even after seasonal, time series and measurement adjustments.


After eliminating the obvious, they’re still left with some disturbing possibilities: did we underestimate the anthropogenic effect, the volcanic effect, or is there some missing chemistry?


What they propose are three explanations related to climate change: firstly, an expanded troposphere; secondly, an accelerating Brewer-Dobson circulation; or thirdly, a disproportionate acceleration of it closer to the tropopause. In other words, the ozone is being transported out of this section faster.


If so, it’s a worry because it means the actual repair might be due to more rapid accumulation in the higher stratosphere, rendering the Montreal Protocol targets perhaps too lax from the beginning, that is, unless the higher stratosphere is actually doing the lion’s share of protecting us from UV radiation.


This paper suggests climate change is interfering with the ozone system as well, creating a scenario where the Montreal Protocol, although still necessary, might not yet be sufficient, for repair by 2060.”


Expert comments gathered by the Australian Science Media Centre (AusSMC)


Related content


19 experts respond to the US pulling out of Paris climate agreement


Climate change: now in high resolution


Developing new treatments for skin cancer


Follow us on FacebookTwitter and Instagram to get all the latest science.




About the Author

Lisa Bailey

Published By

Science and technology is as much a part of our cultural fabric as art, music, theatre and literature. They play a significant role in our daily lives, yet, in a world dependent on science, we often take them for granted. Australia’s Science Channel believes every citizen has a right, and a responsibility, to be informed, and our mission is to create programs to bring that about.


Featured Videos

Placeholder
Alan Duffy on what it took to get humans to the Moon
Placeholder
Do aliens exist? Brian Cox explains
Placeholder
From Apollo to Pulsars: Parkes still dishing out the discoveries
Placeholder
Brian Cox on black holes
Placeholder
Australia's 60,000 years of space history
Placeholder
In Class With… Jane Goodall
Placeholder
Etienne Rastoin-Laplane - What's fishy about the Galapagos?
Placeholder
Kit Prendergast - Flowers to keep native bees buzzing
Placeholder
Rebecca Wellard - Eavesdropping on killer whales
Placeholder
Hossein Tavassoli - Mending broken hearts
Placeholder
Dilan Seckiner - Forensic gait analysis
Placeholder
Samuel Bladwell - A new spin on electronics
Placeholder
Sathana Dushyanthen - The double-edged cancer sword
Placeholder
Dwan Price - Nuts and Guts
Placeholder
Catriona Nguyen-Robertson - Exercise takes your immune system for a ride
Placeholder
Thimo Ruethers - The deadly danger of crocs on a plate
Placeholder
Amanda Tauber - Slamming the brakes on metastatic cancer
Placeholder
Hayley Teasdale – The ball that prevents falls (FameLab Australia 2019 Runner-up)
Placeholder
In the Shadow of a Black Hole
Placeholder
In Class With... Monica Gagliano
Placeholder
In Class With... Brian Cox
Placeholder
Start your FameLab 2019 journey now
Placeholder
Nural Cokcetin - It all starts with FameLab
Placeholder
Erinn Fagan-Jeffries - It all starts with FameLab
Placeholder
Ronald Yu - It all starts with FameLab
Placeholder
Noushin Nasiri - It all starts with FameLab
Placeholder
Grassroots
Placeholder
What is machine learning?
Placeholder
Mythbusting artificial intelligence with expert Anton van den Hengel
Placeholder
Using machine learning to predict medical outcomes
Placeholder
KCLOC
Placeholder
Nature Calls
Placeholder
Mexican Fishing Bats
Placeholder
Bittersweet
Placeholder
Timelapse
Placeholder
Invisible Blanket
Placeholder
Look
Placeholder
The Anomalies: Venom Race
Placeholder
Science Meets Making
Placeholder
Spiral
Placeholder
Looking Out There
Placeholder
Protectors of the Penguins
Placeholder
Astroturf
Placeholder
Virtual Humans
Placeholder
Rancheros del Jaguar
Placeholder
Searching For Dark Matter
Placeholder
Finding prehistoric mega-shark fossils on Victoria's coast
Placeholder
The Grandfather of computers
Placeholder
James Cameron talks science
Placeholder
In Class With.....David Suzuki - The Environment
Placeholder
In Class With.....David Suzuki - Career
Placeholder
Sustainable water use with Doug Green
Placeholder
Why is Indigenous science important?
Placeholder
Vanessa Pirotta - Using drones to collect whale snot (FameLab Australia 2018 Winner)
Placeholder
Toby Hendy - Poking Plants (FameLab Australia 2018 Runner-Up)
Placeholder
Muthu Vignesh Vellayappan - Groovy Patches (FameLab Australia 2018 Audience Choice)
Placeholder
Taryn Laubenstein - The Tail of Two Fishes
Placeholder
Richard Charlesworth - Coeliac disease diagnosis can be a pain in the posterior
Placeholder
Pegah Maasoumi - Solar Windows
Placeholder
James Wong - Breathing while you hop: How do kangaroos do it?
Placeholder
Ben McAllister - The ORGAN Experiment: Shining a light on dark matter
Placeholder
Mortaza Rezae - Empowering beautiful minds
Placeholder
Zane Stromberga - Can allergy drugs beat bladder disease?
Placeholder
Working In.....Art - Astrophotography
Placeholder
What's the best way to move - springs or muscles?
Placeholder
FameLab Australia Semi-Final Highlights
Placeholder
Saving lives with platypus milk
Placeholder
Australian astronomers witness death throes of a cocooned star
Placeholder
How Australia's politicians see our future in space
Placeholder
Keeping satellites in the loop
Placeholder
Tim Flannery talks about COP
Placeholder
Tim Jarvis & Tim Flannery talk Climate Change
Placeholder
Andy's Week in Science - robo baby, university rankings, and cancer on circadian rhythms
Placeholder
From chocolate factory to surgery - the milliDelta robot
Placeholder
Andy's Week in Science: video games, low tech transition windows and a new CRISPR technique
Placeholder
Science lessons useful in Art Restoration career
Placeholder
Are drones the future of racing?
Placeholder
The future of esports according to the experts
Placeholder
Seeing is believing with artist Eugenie Lee
Placeholder
The human impact of Art Science collaboration
Placeholder
Follow your Interests in Robotics
Placeholder
Zoz on 3D Printing
Placeholder
Flavia Tata Nardini on women in engineering
Placeholder
Flavia Tata Nardini on the future of the internet
Placeholder
Explore the ocean floor and Antarctic biodiversity
Placeholder
Follow your interests in Medical Research
Placeholder
Artists on Science
Placeholder
What is Space Archaeology?
Placeholder
Follow your Interests
Placeholder
Scientists on Art
Placeholder
3D Printing in Medical Research
Placeholder
Ethical Issues
Placeholder
Problem Solving - Robotics at Dermatec
Placeholder
Problem Solving with CSI
Placeholder
Tamarah King - Earthquake Geologist
Placeholder
True or False with Bajo and Rad BONUS ROUND
Placeholder
True or False with Bajo & Rad
Placeholder
Andy's Week in Science - Cats vs Dogs
Placeholder
FameLab 2018 - Get Involved!
Placeholder
Nural Cokcetin - How FameLab changed my life
Placeholder
Erinn Fagan-Jeffries - How FameLab changed my life
Placeholder
Noushin Nasiri - How FameLab changed my life
Placeholder
Ronald Yu - How FameLab changed my life
Placeholder
Alan Duffy's Top 5 Science Communication Tips
Placeholder
A Judge's Top Tips for FameLab Australia
Placeholder
Brain Candy - Why, Why, Why Michael Stevens?
Placeholder
The Past, Present, and Future of Malaria
Placeholder
This is a video of poo pills being made!
Placeholder
Mind Games - Sports Psychology
Placeholder
Fuel to Win - Sports Nutrition
Placeholder
Fifty years since Australia beat the world to space
Placeholder
ECR Network: Talk Your Science with Alan Duffy
Placeholder
Andy's Week in Science - chimps, klompen, and clouds
Placeholder
Our robot medicine future - heart huggers and micro biohybrids
Placeholder
Six Awkward Cancer Questions
Placeholder
How do you tell if a whale is left-handed?
Placeholder
She Flies - Turning Girls into Drone Pilots
Placeholder
Andy's Week in Science - Magnetic Fabric, Cancer Treatments, and Echolocation
Placeholder
The Science of Sexuality
Placeholder
Sailing Through Space with Bill Nye
Placeholder
Using Sports Science to Help Olympic Athletes
Placeholder
Three and a Half Minutes of Top Shelf Career Advice
Placeholder
New Space Tech with Andrea Boyd
Placeholder
Kelly Meets the Mars Curiosity Rover
Placeholder
Hearts, Opera, and Tough Conversations - Andy's Week in Science
Placeholder
Bill Nye on Science, Girls, and Saving the World!
Placeholder
2017 Prime Minister's Prizes for Science Part 2
Placeholder
2017 Prime Minister's Prizes for Science Part 1
Placeholder
Who Decides the Law in Space?
Placeholder
Scientists Watch Collision That Created Gravitational Waves
Placeholder
Getting Cold Feet Leads to a Whole New Career
Placeholder
ECR Network - Why Every Scientist Should Be on Twitter - The Benefits
Placeholder
ECR Network - Why Every Scientist Should Be On Twitter - The Fears
Placeholder
Live Podcast - Life Vs Science
Placeholder
Origami Robots, Babies, and Kidneys - Andy's Week in Science
Placeholder
Namira Salim and the Zero-G Peace Summit
Placeholder
Elon Musk's Mars Plan: Expert Analysis
Placeholder
SPACE AF - Thursday
Placeholder
My Time in Space
Placeholder
IAC TV Daily Broadcast - Wednesday
Placeholder
SPACE AF - Wednesday
Placeholder
IAC TV Daily broadcast - Tuesday
Placeholder
SPACE AF - Tuesday
Placeholder
IAC TV daily broadcast - Monday
01:00:41
Placeholder
SPACE AF - Monday
Placeholder
Live from IAC 2017
Placeholder
Brew Ha Ha - Technology Rewrites History
Placeholder
Methamphetamine - Gateway Drug to Parkinson's Disease
Placeholder
Concussion, 3D BioPrinting, and The Universe - Andy's Week in Science
Placeholder
Pulsars, Clearwigs, and Pacemakers - Andy's Week in Science
Placeholder
Revolutions - The Quest to Transform HPV Racing
Placeholder
Brew Ha Ha - Hurricane Irma Blows Away Tesla's Rip Off
Placeholder
Brew Ha Ha - The Limit of Your Lifespan
Placeholder
The Recipient
Placeholder
Think Like a Scientist: Natural Selection in an Outbreak
Placeholder
The End of Snow
Placeholder
The Next Rembrandt
Placeholder
The Discarded
Placeholder
The Spectators
Placeholder
Test Tube Babes
Placeholder
Pangolins in Peril- A Story of Rare Scales
Placeholder
Rock Art Project
Placeholder
Pork.0
Placeholder
OWSIA (Darkened Water)
Placeholder
Nex
Placeholder
Northern Quolls
Placeholder
Dish Life
Placeholder
At Street Level
Placeholder
Custom Love
Placeholder
Adrift
Placeholder
A Story from Space
Placeholder
Brew Ha Ha - The Most Dangerous Thing in Boxing May Be the Gloves
Placeholder
ECR Network 2017 – Get Interdisciplinary!
01:27:00
Placeholder
Chris Hadfield: The Future of Space Exploration
Placeholder
Chris Hadfield: Life After Space
Placeholder
Chris Hadfield: Life in Space
Placeholder
Brew Ha Ha - Let's Make Algae Australian of the Year
Placeholder
Brew Ha Ha - Australia's Energy Showdown
Placeholder
Nine Awkward Astrophysicist Questions
Placeholder
Brew Ha Ha - There's No Such Thing as an Exercise Pill
Placeholder
National Science Week Awards Show
Placeholder
Brew Ha Ha - Your 5 Step Asteroid Success Plan
Placeholder
National Science Week Forecast
Placeholder
Open Doors. Open Future. Open Day.
Placeholder
Brew Ha Ha - Lose a Little to Gain Millions
Placeholder
Brew Ha Ha - Crowd Sourcing Origami Astronaut Protection
Placeholder
Brew Ha Ha - T-Rex's Prehistoric Power Walk
Placeholder
True or False with Kale Brock
Placeholder
The Grandfather Paradox
Placeholder
Brew Ha Ha - The Hidden Heroes Tackling Mozzies
Placeholder
Brew Ha Ha - Emergency AI Assistance
Placeholder
Brew Ha Ha - Frogs Forever, Dinosaurs Never!
Placeholder
Brew Ha Ha - Australia, Let's Go To Space
Placeholder
Brew Ha Ha - Welcome to the Microbiome, Archaea!
Placeholder
Brew Ha Ha - Roos Blindside Driverless Cars
Placeholder
Biodiversity of Antarctica Under Threat From Increase In Ice-Free Areas
Placeholder
Brew Ha Ha - The Future of the Census
Placeholder
Tell Me! Brian Cox
Placeholder
Crash, Burn, Tweak, Repeat
Placeholder
Brew Ha Ha - Humans Just Got Older and Wiser
Placeholder
Brew Ha Ha - Cheers to Brain Health?
Placeholder
Gene Therapy Could Cure Allergies
Placeholder
Brew Ha Ha - iHeart Hacking
Placeholder
Ridiculology - New Hubble
Placeholder
Brew Ha Ha - Trees Alone Can't Save Us
Placeholder
Brew Ha Ha - Earth's Accidental Force Field
Placeholder
Dinosaurs on the Big Screen
Placeholder
Brew Ha Ha - Farewell MP3
Placeholder
Kids Beat Grown-ups on Pneumonia Vaccines
Placeholder
Brew Ha Ha - The Booger Conspiracy
Placeholder
FameLab 2017 National Final - Part 2
Placeholder
FameLab 2017 National Final - Part 1
Placeholder
2017 Budget Response
Placeholder
What Are Animal Weapons?
Placeholder
If You Love Both Art and Science, Be a Scientific Illustrator
Placeholder
Getting Personal With Skinks
Placeholder
Brew Ha Ha - CSIRO Email Leaks
Placeholder
FameLab 2017 Western Australia Semi-Final Highlights
Placeholder
Brew Ha Ha - New Hope for Premmies
Placeholder
Brew Ha Ha - Britain Goes Coal-Free
Placeholder
Brew Ha Ha - Naked Mole-Rats (SFW)
Placeholder
Brew Ha Ha - Easter Reminders
Placeholder
Meet Andrea Boyd - Space Flight Controller
Placeholder
Brew Ha Ha - Sperm Drug Smugglers
Placeholder
FameLab 2017 New South Wales Semi-Final Highlights
Placeholder
The Science of Fiction
Placeholder
Brew Ha Ha - Liquorice Poisoning
Placeholder
Brew Ha Ha - Crowdsourcing Science
Placeholder
FameLab 2017 Queensland Semi-Final Highlights
Placeholder
Brew Ha Ha - SpaceX Preps for Relaunch
Placeholder
Poly Cystic Ovary Syndrome Breakthrough
Placeholder
Brew Ha Ha - Surviving a Media Storm
Placeholder
Will This Aussie Team Win the Race to Create the Ultimate Malaria Vaccine?
Placeholder
Brew Ha Ha - New Dino Family Tree
Placeholder
How to fix things with Kyle Wiens
Placeholder
Repair or replace? iFixit co-founder Kyle Wiens
Placeholder
Special Investigation - No Alternative to Cancer
Placeholder
Brew Ha Ha - Raspberry Pi is Number 3 Best-Selling Computer
Placeholder
If reefs can't adapt, are they doomed?
Placeholder
Art, Music, Science, Society - Sir Tim Smit Has Thoughts On It All
Placeholder
Assembling the Best Team (according to Sir Tim Smit)
Placeholder
What's up with the Rogue Ginger?
Placeholder
Make Me A Martian
Placeholder
Brew Ha Ha - Recognising the Ethical Dilemma in Facial Tracking Software
Placeholder
Science Communication Around the Globe
Placeholder
Brew Ha Ha - Elon to the Rescue
Placeholder
Sing Us a Song, Spaceman!
Placeholder
Feather Map Of Australia Citizen Science Project