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We’ve all heard of Climate Change. Greta has told us all about it. David Attenbourgh
has forced us all to watch walrus’s die. Icecaps are melting, Australia is burning.
It’s been intense. The vast majority of scientists believe that human industries are
radically transforming the climate. Looking at the headlines you’d think climate
change snuck up on us suddenly out of nowhere. Surely we’ve only known about greenhouse
gases for a few decades at the most. Yeah, Exxon knew about the effects fossil fuels
were having on the climate back in the 70’s did their best to suppress it. But surely
it couldn’t go back much further than that could it? Yeah….Try about 200 years.
----Intro---- Cogito is more of a humanities type person
and not a scientist. Any of the science explained in this video is simplified and is to the
best of my understanding. I am not a scientist nor am I a warlock. Feel free to correct any
mistakes in the comments and I will address them.
Climate Change is happening for a number of different reasons, but the main culprit is
Greenhouse Gases like carbon dioxide, emitted from the burning of fossil fuels like coal
and oil. So what exactly is a greenhouse gas and how
do they affect our climate? This is our planet. This is the sun. The sun
shoots solar radiation towards Earth and these solar rays can easily pass through the gases
in our atmosphere. The Earth absorbs these rays, heats up, and then emits them as thermal
radiation or heat. This radiation however can be absorbed by certain gases in our atmosphere.
So some of this heat goes back down towards Earth and warms it. This forms a greenhous-like
heating trapping barrier around Earth. The more greenhouse gases in the atmosphere the
more heat gets trapped. Since the industrial revolution, carbon dioxide
levels have risen more than 30% and our desire for more land has caused us to chop down or
burn huge amounts of carbon absorbing forests. BUT DON’T LET THE EXISTENTIAL DREAD SET
IN...DON’T LET THE EXISTENTIAL DREAD SET IN.
Fourier The first human person to theorise something
like the greenhouse effect was Joseph Fourier. This clever Frenchman was trying to figure
out why the Earth wasn't a frozen wasteland. He calculated how much energy the Sun bombarded
the Earth with and realised that our planet should be much colder.
Something must have been trapping the sun’s heat.
In an 1824 paper he hypothesised “heat in the state of light finds less resistance in
penetrating the air, than in repassing into the air when converted into non-luminous heat.”
This was description of the greenhouse effect, and it was made by a guy that was friends
with Napoleon. Fourier never actually used the term greenhouse. He didn’t even conduct
an experiment to test his hypothesis or pinpoint which gas could cause the effect.
Foote That answer would come from the most unlikely
of creatures, a hobbit...no it wasn’t a hobbit? You’re telling me someone with the
name Eunice Newton Foote isn’t a hobbit? Ok whatever. Foote was a woman however, so
in the eyes of 19th century scientists, her opinion was about as relevant as a hobbit’s
anyway. Which we’ll see shortly. Having made the awful decision to be born
a woman in 19th century America, Foote didn’t have much hope at becoming a scientist as
women were not offered much scientific education at the time. But she did enjoy science and
had a curious mind, so she conducted her own amateur scientific experiments.
Eunice wanted to know how gases interacted with sunlight.
So she conducted an experiment. She placed thermometers in glass cylinders and added
different gases and varying amounts of moisture with an air pump.
She then placed the cylinders in the sun to measure the temperature difference over time.
She tested gases such as water vapor, common air, and CO2. She noticed the cylinders filled
with water vapor or CO2 heated quicker and remained hot longer.
From this she speculated that “An atmosphere of [carbon dioxide] would give to our earth
a high temperature; and if as some suppose, at one period of its history the air had mixed
with it a larger proportion than at present, an increased temperature…must have necessarily
resulted.” Her paper was presented by a male scientist
on her behalf at the American Association for the Advancement of Science in 1856. And
published the same year in the American Journal of Arts and Science.
Foote had built upon Fourier’s idea, but she actually tested it and discovered that
CO2 was one of the greenhouse gases that trap heat in our atmosphere. She correctly hypothesised
that changing the levels of CO2 would change the Earth’s temperature, laying the foundation
for modern climate science. But no one paid attention to her work. No
one saw how significant of a hypothesis this was. Eunice became a footnote in climate history.
Tyndal Instead, the credit for the discovery of the
greenhouse effect and greenhouse gases is given to Irish scientist John Tyndall.
Tyndall was obsessed with a question that dominated Victorian era science: The Ice Age
Theory. It had recently been discovered that large
parts of the Earth were once covered with ice and scientists were fascinated with answering
what had caused the ice ages. Which there are 5 of somehow. How did they
rope Patrick Stewart in this..... Name Ariscratle, a saber-toothed squirrel that lives on Scratlantis.
Fur is Grayish-brown apparently....that's nice. Where were we again?
There were a few theories floating about on what could have caused these ice ages. The
first and most obvious was Frost Giants. But Tyndall like Fourier and Foote argued the
atmosphere could change the Earth's temperature. To test whether gases could trap heat he built
this insane looking thing, however it’s actually quite easy to understand.
Basically, heat is pushed through this tube. The tube is filled with the gas being tested.
The heat leaves the tube, hits this cone and the heat level is compared against the heat
hitting this control cone. Using this heat difference Tyndall could calculate how much
heat the gas in the tube had absorbed.
His results showed that water vapor and CO2 along with some other gases were the primary
heat absorbers. He found that CO2 could trap 1,000 times as much heat as common air.
“The solar heat possesses, in a far higher degree than that of lime light, the power
of crossing an atmosphere; but, when the heat is absorbed by the planet, it is so changed
in quality that the rays emanating from the planet cannot get with the same freedom back
into space. Thus the atmosphere admits of the entrance of the solar heat, but checks
its exit; and the result is a tendency to accumulate heat at the surface of the planet.”
—John Tyndall (1859) He had perfectly described the greenhouse
effect and proven it with his cones, which is why he is normally credited with discovering
it. His experiment revealed what Foote had discovered
3 years before. But in Tyndall’s later writings, he claims “With regard to the action of
other gases upon heat, we are not, so far as I am aware, possessed of a single experiment.”
One could argue the Tyndall must have seen her work since the journal that carried Foote’s
paper also carried one by Tyndall on color blindness. If he went to go look at his published
work he easily could have seen hers. We’ll unfortunately never know if he read her paper
or not though. But Tyndall’s experiment did correct some
problems with Eunice's by being able to isolate heat radiation for example.
Which isn’t surprising due to his advanced scientific education. His experiment has been
much more influential in the field of climate science than hers.
But Eunice’s great idea, in the end, wasn’t her experiment. It was her hypothesis that
changes in the amount of carbon dioxide in the atmosphere could alter our planet's temperature.
And, as far as I know, she was the first person to think this. This was 150 years ago, this
is pre American Civil War. Who knows what she would have achieved if
she'd had Tyndall’s advantages. Arrheius
The final piece of the climate change puzzle was put together by Swedish physicist Svante
Thunberg Arrhenius in 1896. Who created what we could call the first climate change model
predicting that human industry could severely affect the climate.
And yes this Svante Thunberg Arrhenius is related to Svante Thunberg, father of Greta
Thunberg. I guess that family just has a knack for pointing out the dangers of climate change.
Like Tyndall, Arrhenius, was also interested in the Ice Ages debate. He liked Tyndall's
idea that changes in the atmosphere like decreased CO2 levels could have caused Ice Ages.
So he wanted to calculate how much CO2 it would take to change global temperatures.
Luckily for him another Swedish scientist Arvid Högbom, had recently published an essay
estimating how much CO2 been in the athmosphere throughout history.
With this information at hand Arrhenius began calculating how much heat would be trapped
if levels of CO2 changed. Arrhenius did tens of thousands of calculations. All by hand,
with no calculator. He discovered that cutting the amount of CO2
in the atmosphere by half could lower the temperature in Europe some 4-5°C. Which is
an ice age level. This explained how the Earth might have cooled
but this sparked another interest for Arrheius. Could this also cause the Earth to heat up?
Arvid Hogborn in his calculations of how much CO2 was in the atmosphere throughout history
included things like emissions from volcanoes but he thought to include the emissions from
human industry, like factories. Looking at this Arrhenius realised if you
doubled the amount of CO2 in the atmosphere, it would raise the world’s temperature by
5-6°C Celsius and that if humanity continued to burn fossil fuels and pump greenhouse gases
into the atmosphere we could trigger this rise in temperature.
Which is according to Isabel Hilton “a conclusion that millions of dollars worth of research
over the ensuing century hardly changed at all,”.
Arrhenius was the first person to predict that our burning of fossil fuels could cause
global warming. Predictions
Arrhenius however didn’t think it would ever be a problem. For him this was all hypothetical.
He didn’t imagine we could ever manage to burn enough fossil fuels to ever seriously
impact the climate. Arrhenius predicted that climate change would happen….eventually.
But he thought it would take 3,000 years for CO2 levels in the atmosphere to rise by 50%.
They’ve shot up by 30% in only a 100. DON’T….LET….THE...EXISTENTIAL.....DREAD….SET….IN Anyway temperature increase probably didn’t
sound too bad these Swedish scientists. Some scientists like Walter Nernst even thought
about burning more coal for no reason other than to release CO2 to purposefully heat the
Earth. Dafuq Walter...come on. Arrhenius even liked the idea of global warming.
“By the influence of the increasing percentage of carbonic acid in the atmosphere, we may
hope to enjoy ages with more equable and better climates”
They couldn't imagine the negative effects of climate change. The mass extinctions, the
negative feedback loops, the environmental collapse, the depressing David Attenbourgh
documentaries. Seriously everyone, the walrus scene ruined my life. I haven't been the same
since. Climate Change might seem like it arrived
all of a sudden, if you judge by panic tweets, depressing headlines, and global protests.
But the science predicting it is very old. We just weren't paying attention
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