We need to remember that there are success stories from our parents' generation, in the 1980s, of fighting the climate change issues of their time. These were the Hole in the Ozone Layer and Acid Rain. They got together and addressed it. This presentation looks back at what that was about, and how they fought it. We need to take lessons from their playbook, and speak up whenever we hear the doom and gloom voices saying it's all hopeless nowadays!

1. WHAT DO I NEED TO
KNOW ABOUT CLIMATE
CHANGE?
DAY TWO: REASONS TO BE OPTIMISTIC THAT WE CAN TACKLE GLOBAL WARMING!
GUP-SHUP SESSIONS
MOHUA MUKHERJEE
FEBRUARY 2021

2. DAY TWO: OVERVIEW
 THIS PRESENTATION TELLS THE STORY OF AN OLDER GENERATION OF PRODUCTS THAT USED TO BE MADE
USING GASES THAT CONTAIN SUBSTANCES WHICH HARM OUR PLANET, WHICH WE NO LONGER USE!
 WE NEED TO KNOW ABOUT THESE GASES BECAUSE THEY USED TO BE ASSOCIATED WITH EVERYDAY PRODUCTS
OUR PARENTS AND GRAND-PARENTS WERE REGULARLY USING!
 THESE GASES OF THE 1970s and 1980s CAUSED HARM TO THE OZONE LAYER, BY CREATING A HOLE IN IT THAT
WAS EXPANDING IN SIZE—THEY ARE ODP GASES (“OZONE DEPLETING POTENTIAL”--details to follow)
 A HOLE IN THE OZONE LAYER EXPOSES US TO HARMFUL UV RADIATION FROM THE SUN, AND GREATLY
INCREASES THE RISK OF SKIN CANCER AND CATARACTS
 OUR CHALLENGE TODAY, IN THE PAST TWO DECADES, COMES FROM “HEAT-TRAPPING GASES” (CALLED
GREENHOUSE GASES) AS THEY CAUSE THE EARTH’S AVERAGE TEMPERATURE TO RISE AT AN INCREASING RATE
 THIS IS CALLED GLOBAL WARMING. A RISE IN THE EARTH’S AVERAGE TEMPERATURE CREATES EVER MORE
FREQUENT NATURAL DISASTERS SUCH AS FLOODING, HURRICANES, DROUGHTS, HEATWAVES.
 IT ALSO CAUSES SEA LEVEL RISE, GLACIER MELT, PERMAFROST MELT, AND RISK OF NEW DISEASES.
 VAST AREAS BECOME TOO HOT TO LIVE IN, AND CANNOT SUPPORT LIFE FOR PEOPLE, PLANTS AND ANIMALS.
 THIRTY YEARS AGO, WHEN THE SCIENTIFIC EVIDENCE POINTED TO THE LINK BETWEEN OUR ACTIVITIES AND
THE HOLE IN THE OZONE LAYER, THE WHOLE WORLD MOBILIZED TO STOP IT. IT WORKED!
 THAT WAS IN 1987. NOW IT IS OUR TURN—OUR CHALLENGE IS GREATER, BUT WE CAN DO IT AGAIN
 LET’S LOOK AT WHAT OUR PARENTS AND GRANDPARENTS DID AND INSPIRE OURSELVES!

3. SIMILARITIES BETWEEN THE OZONE HOLE STORY OF
THE 1970s AND THE GLOBAL WARMING STORY OF THE
2000s
 In the 1970s and 80s, scientists pointed out that some human daily activities were
gradually creating dangerous conditions for all inhabitants of the planet
 Humans unwittingly made and used products that released gases which were
damaging our entire planet.
 These gases were not creating direct harm to the users, so they were not noticed for
a long time.
 The gases from everywhere, were causing damage to the ozone layer over the
Antarctic (where no one lived)—our previous generations tackled those successfully
in 1987. The ozone layer should be good again by 2050.
 They solved it together by every country agreeing to phase out their use of such
dangerous gases on a timetable.

4. SIMILARITIES BETWEEN THE OZONE HOLE STORY OF
THE 1970s AND THE GLOBAL WARMING STORY OF THE
2000s (cont.)
 The other group of gases, which are endangering us NOW, are harmful because they trap heat and
raise the average temperature of the earth.
 These are Greenhouse Gases (GHGs). It is as if they form a thick, heat-trapping blanket over the
atmosphere, that the Earth cannot shake off.
 The more of these gases we pump into the air, the thicker we make that unwanted “blanket” in the
atmosphere, and the hotter it gets on the ground where we live.
 We need to work together on getting rid of those global warming gases, just as we did before with
ozone-depleting gases. (This will be covered in DAY THREE slides).
 First, we have to slow down the rate at which we produce greenhouse gases, and then we have to
altogether stop releasing them. At the same time, we also have to “absorb them” and mop them up,
through creating more “carbon sinks”, and thereby clean up their most harmful elements.
 The major Greenhouse Gases will not disappear for 100 years or more, once they are up there in our
atmosphere, so it’s urgent to act NOW and slow down how much of them we pump into the air. It’s like
braking a car, and then coming to a stop. IT IS HIGH TIME TO STEP ON THE GHG BRAKES NOW!

5. SIMILARITIES BETWEEN THE OZONE HOLE STORY OF THE
1970s AND THE GLOBAL WARMING STORY OF THE 2000s
(cont.)
 BACK TO THE 1980s: The release of these ozone depleting harmful gases resulted from everyday activities that
everyone was used to and did not think they could give up.
 The good news is that they didn’t have to give them up. They just had to make their products in a different way! They
had to find new technologies that did not use the harmful substances.
 In our case, even though our challenge looks much bigger, there is good news: we already have the technology
TODAY, which we need in order to fight most of the GHG battle! We don’t have to find new ways. We know how to
do most things that will cut back our emission of GHGs.
 It’s just a question of everyone making the changeover to using these technologies.
 Governments need to lead the way by setting targets, announcing regulations and setting an example. With
domestic regulations we can be sure that no one is tempted to cheat, and it’s a level playing field in our country.
Regulations won’t be identical everywhere.
 Countries which release the most GHGs today, need to show that they are seriously cutting back, so that other
countries will follow. If the large GHG emitters don’t take action, the small emitters will not be able to make a
difference for the planet by struggling alone, to do their part.
 The GHG-reduction technologies also need to be shared with countries that did not invent them, but that need them
in order for everyone to make the green transition for the common good.

6. THE “OZONE LAYER” STORY IN SUMMARY…(and some
terminology for you)
 How did we save the Ozone layer in the 1980s? A hole had appeared in the Ozone layer,
that was rapidly increasing in size. The Ozone layer is a protective layer in the stratosphere.
The growing hole in it was harmful to the health of living things on the earth’s surface.
 Scientists noticed that we were using lots of products made with gases which contained
Ozone Depleting Substances (ODS)
 These were gases like CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons,
which are also described as having ODP (ozone depleting potential).
 CFCs, which are still found in cooling equipment produced before 1995, were especially
bad as they also had high Global Warming Potential (GWP) apart from depleting the
Ozone Layer!
 They are banned worldwide now, as a result of an international agreement that
nearly 200 countries signed up to, but the old gases that were released into the air
previously, are still up there doing damage, and will only gradually be eliminated.

7. THE “OZONE LAYER” STORY IN SUMMARY…(and some
terminology for you) (cont.)
 The answer at the time, in the 1980s, was to switch over to more climate friendly HFCs
(hydrofluorocarbons, that were missing the chlorine which was in the earlier substances).
 Chlorine and Bromine were the two “bad guys”, with high Ozone Depleting Potential
(ODP). So, as hard as it was, our parents forced themselves to stop using the products that
released these two bad guys and hurt the ozone layer.
 Now that it is our turn to change things, we can surely do it too!
 Nowadays, almost all countries have issued regulations to phase out the industrial use of
ODS, and are committed to follow these regulations through an international treaty.
 The hole in the Ozone layer, that was getting bigger as countries everywhere used more
Ozone Depleting Substances (ODSs), was potentially deadly. This is exactly analogous to
how potentially deadly the greenhouse gases (GHGs) are today. There is no time to waste!

8. THE “OZONE LAYER” STORY IN SUMMARY…(and some
terminology for you) (cont.)
 The Ozone hole was allowing more UV radiation from the Sun to get through to the Earth. This in turn
was sharply increasing the rates of skin cancer and cataracts for humans (and was also probably
harming many other mammals and affecting their population sizes, potentially creating biodiversity
havoc).
 Success came after over 100 countries voluntarily signed up to an agreement called the Montreal
Protocol in 1987, which is one of the most successful climate agreements ever (so far)!
 One of the likely reasons for its quick success:
 Under the Montreal Protocol, developing nations were assisted by
technical support and a multilateral fund to catch up with their
international commitments.
 The Montreal Protocol has also been updated and amended around 9 times by now, as scientists
regularly find new things that need to be done to protect the ozone layer.

9. THE “OZONE LAYER” STORY IN SUMMARY… (cont.)
 Why does it keep needing to be amended?
 Here is an analogy: It’s as if all countries had first agreed to put away the sharp knives
but realized they would also need to put away blades and the scissors and the clippers
and anything else (the analogy refers to any other substances that turn out later to
also harm the ozone layer, as scientists develop better technologies to study the
properties of different substances)!!
 At that time, our parents’ generation needed the knowhow to find out what else they
could use instead and how to put it into regulations that would create domestic bans
of the old substances and incentives for adoption of the new ones.
 For this the developing countries needed technical support (including legal expertise)
and monetary help from industrialized countries. They got it, and the ozone layer was
saved.
 We congratulate the previous generation, and we use their example to say that today’s
leaders must rise to the challenge! Not only the leaders—we ourselves must each do
our part too…

10. THE “OZONE LAYER” STORY IN SUMMARY… (cont.)
 The Montreal Protocol was not a static document. Those ongoing updates and
refinements of permitted and non-permitted substances are the later amendments to the
Montreal Protocol that most of the original signatory countries volunteered to commit to,
based on newer scientific evidence.
 It’s all working out well. Scientists say the Ozone layer is now recovering and will be good
again by 2050!
 BY THE WAY…. What everyday products are we talking about, that were causing this?
These are the products that today are made with newer and cleaner technologies:
 Refrigerants (cooling processes in fridges and air conditioner technology used to be done
with gases containing ingredients that were killing the ozone layer). Today they use
different, safer substances that do not have Ozone Depleting properties.
 Also, older versions of aerosol Spray cans (the harmful ODS gas was in the propellant that
sent out droplets of whatever was in the can). Those are not in today’s spray cans.

11. THE “OZONE LAYER” STORY IN SUMMARY… (cont.)
 Exceptions have been made in the regulations for things like fire extinguishers and
inhalers to treat asthma, where alternative propellants are not easily available.
 But for all other spray cans and solvents, the old substances are no longer
permitted, in every country, because they signed up to an international agreement
in 1987 promising to get rid of products containing ODS, on a timetable
 That is why today we happily live with modern and safe Air Conditioner and
Refrigerator and Aerosol and Solvent technology that does not use ODS (ozone
depleting substances).
 No one is killing the ozone layer anymore, that’s why it is recovering!

12. WERE THERE LOTS OF NEW GREEN JOBS CREATED AS
A RESULT OF SWITCHING TO NEW OZONE LAYER
SAVING TECHNOLOGIES?
 JOB CREATION IS REALLY IMPORTANT TO MENTION. Was there any upside for our
parents’ generation, apart from health benefits, to giving up Ozone Depleting
Substances?
 Yes, certified HVAC (HEATING VENTILATION AIR CONDITIONING) professionals were
and are in high demand, well-paid, and their jobs such as installation and repair and
servicing, cannot be off-shored or “exported”, by definition.
 Certified Refrigerator and Air Conditioner manufacturers and service technicians who
are trained in the safe use of non-ODS containing chemicals and also trained in
repairing leaks and damaged cooling equipment, are likewise in high demand
 As the climate warms and the use of refrigerators and air conditioners proliferates
everywhere, it is more important than ever to reflect on how much damage to the
planet and to human (and animal) health has been AVOIDED by the collective action
of signing up, all those years ago, to the use of non-ODS gases

13. LET’S NOT FORGET ACID RAIN, WHILE WE ARE STILL
THINKING OF THE 1970s and 1980s
 We can’t leave this topic without a brief mention of ACID RAIN, that our parents dealt with apart
from the hole in the Ozone layer.
 There was another set of nasty gases in the atmosphere, containing sulphur and nitrogen, which
escaped into the air directly from smoke-stacks at coal plants, where coal was burned to make
electricity
 These emissions in the atmosphere would acidify rain-water and come back down to the earth,
dissolved in raindrops
 This polluted precipitation caused nasty effects on the ground, like acidifying lakes and killing fish
populations or starving them by killing their food. It even started to melt and damage metal statues
and gravestones! It stripped many leaves directly off their trees and left denuded forests.
 At one time acid rain was the number one bilateral issue between Canada and the United States!
The Clean Air Act was passed in the United States order to clean up air pollution and stop acid rain.
 Our parents’ success at combatting acid rain is another reason for optimism about combatting
climate change.
 You can find a detailed account of the acid rain story here, in a long read:
https://www.bbc.com/future/article/20190823-can-lessons-from-acid-rain-help-stop-climate-change

14. NEXT TIME:
WHY ARE GREENHOUSE GASES SO IMPORTANT? HOW DID WE GET
ADDICTED TO THEM, AND HOW CAN WE GET OUT OF IT?