Saving the
world is a lot trickier than Bruce Willis makes it seem. The more we learn
about humanity’s influence on the processes of nature, the more we understand
that the earth is a very complex thing, full of dynamic and constantly changing systems. For that reason, people often end up confused and frustrated when we try to undo some
of the harm we have caused. Climate change in particular is enough to make
people switch off their brains and wait for a new topic. It is a big unruly problem and it
often seems like no matter what we do, we can’t fix it. However, recent
evidence from Antarctica is beginning to show that the changes we make can have
a positive impact on environmental problems
It all
began back in the 1930’s with a man named Thomas Midgley, an inventor who was riding high after his
creation of a new form of gasoline that solved a problem called engine
knocking. His handy solution was to put lead in the gas. Little did he and
everyone else on the planet know, but eventually his invention would expand the
amount of lead in the atmosphere (and consequently in the bodies of every man, woman, and child alive) so much that it would eventually be outlawed.
But back in
1930 everything was going well for old Thomas. Following his success with
tetraethyl lead Midgley took a job with General Motors, a company that hoped he could come
up with a chemical for them to use in refrigerators. Back in the early 20th
century your fridge was a pretty dangerous thing. The chemicals used to cool it were
so poisonous that a small leak could result in your whole family suffocating in
their sleep. GM had high hopes that Midgley could fix the problem.
As it
turned out, their confidence was well placed and in no time at all Thomas
Midgley had his name attached to another invention: chlorofluorocarbons (CFCs).
CFCs were harmless to humans and nowhere near as flammable as the old refrigeration chemicals
so they quickly became the molecules of choice for keeping your leftovers cool
and delicious.
However, along with leaded gasoline, CFCs would eventually
become the scourge of the Earth. As it happens, when CFCs get into the
atmosphere they destroy a chemical called ozone. Ozone itself is a bit of a handful. It is just three oxygen molecules
stuck together, instead of the usual two. At ground level, ozone is not your
friend. Your body confuses it with pure oxygen gas and binds it to you red
blood cells where it very swiftly kills you. Up in the atmosphere however,
where it makes up a 3 millimeter thick layer all around the earth
(about the thickness of 2 pennies stacked on top of each other), ozone is great. It blocks harmful UV rays from reaching the surface where they cause skin
cancer and sunburns.
As
developed nations cranked out CFCs at every increasing rates through the 50’s
and 60’s the chemicals found their way into the atmosphere in ever increasing
quantities. Eventually they destroyed enough ozone to create a massive hole in
the ozone layer that forms over Antarctica between September and December of each year.
The hole is isolated to the bottom of the planet because wind currents create
the vortex of super-cold air over the South Pole and cold air multiplies the
effect of CFCs on breaking down ozone.
Clearly
something needed to be done before the entire atmosphere was depleted of ozone and
we were all dying from cancer. In 1987 leaders from nations all over the world
came together and drafted the Montreal Protocol, a document that would phase out
the use of CFCs across the world. The agreement was reinforced in 1997 with
the Kyoto protocol. The people of the world crossed their fingers and hoped for
the best.
So what was
the result? Well, in 2012 measurements of the ozone hole revealed that it was the smallest
it had been in over a decade. The ban on CFCs is actually working in ways we
can see on time scales we can comprehend. In the world of environmental
science, that is a slam dunk. Scientists estimate that by the middle of this
century ozone levels will rebound to where they were in the 1960’s and the
ozone hole should be completely gone sometime in the next 20 years.
To put a
slight downer on an otherwise happy ending, it is possible that the shrinking
of the hole we are observing is due to warmer air temperatures caused by climate change mitigating
the ability of CFCs to break down ozone, but the effect is larger than you
would expect from that alone. The news is still good.
The lesson
to take away from the patching of the ozone hole (aside from not hiring Thomas
Midgley to do anything ever again) is that we can make a difference. When humanity puts its mind to something, we
are able to get it done. We should all go out for a beer to celebrate and then
get to work eliminating fossil fuels.
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