The three-minute story of 800,000 years of climate change with a sting in the tail

The three-minute story of 800,000 years of climate change with a sting in the tail
Ice cores are a window into the past hundreds of thousands of years. Credit: NASA Goddard Space Flight Center/Ludovic Brucker

There are those who say the climate has always changed, and that carbon dioxide levels have always fluctuated. That's true. But it's also true that since the industrial revolution, CO₂ levels in the atmosphere have climbed to levels that are unprecedented over hundreds of millennia.

So here's a short video we made, to put recent climate change and emissions into the context of the past 800,000 years.

The temperature-CO₂ connection

Earth has a natural greenhouse effect, and it is really important. Without it, the average temperature on the surface of the planet would be about -18℃ and human life would not exist. Carbon dioxide (CO₂) is one of the gases in our atmosphere that traps heat and makes the planet habitable.

We have known about the for well over a century. About 150 years ago, a physicist called John Tyndall used laboratory experiments to demonstrate the greenhouse properties of CO₂ gas. Then, in the late 1800s, the Swedish chemist Svante Arrhenius first calculated the greenhouse effect of CO₂ in our atmosphere and linked it to past ice ages on our planet.

Modern scientists and engineers have explored these links in intricate detail in recent decades, by drilling into the ice sheets that cover Antarctica and Greenland. Thousands of years of snow have compressed into thick slabs of ice. The resulting ice cores can be more than 3km long and extend back a staggering 800,000 years.

Scientists use the chemistry of the water molecules in the ice layers to see how the temperature has varied through the millennia. These ice layers also trap tiny bubbles from the ancient atmosphere, allowing us to measure prehistoric CO₂ levels directly.

Temperature and CO₂

The ice cores reveal an incredibly tight connection between temperature and greenhouse gas levels through the ice age cycles, thus proving the concepts put forward by Arrhenius more than a century ago.

In previous warm periods, it was not a CO₂ spike that kickstarted the warming, but small and predictable wobbles in Earth's rotation and orbit around the Sun. CO₂ played a big role as a natural amplifier of the small climate shifts initiated by these wobbles. As the planet began to cool, more CO₂ dissolved into the oceans, reducing the greenhouse effect and causing more cooling. Similarly, CO₂ was released from the oceans to the atmosphere when the planet warmed, driving further warming.

But things are very different this time around. Humans are responsible for adding huge quantities of extra CO₂ to the atmosphere – and fast.

The three-minute story of 800,000 years of climate change with a sting in the tail
Antarctic temperature changes across the ice ages were very similar to globally-averaged temperatures, except that ice age temperature changes over Antarctica were roughly twice that of the global average. Scientists refer to this as polar amplification (data from Parrenin et al. 2013; Snyder et al. 2016; Bereiter et al. 2015). Credit: Ben Henley and Nerilie Abram

The speed at which CO₂ is rising has no comparison in the recorded past. The fastest natural shifts out of ice ages saw CO₂ levels increase by around 35 parts per million (ppm) in 1,000 years. It might be hard to believe, but humans have emitted the equivalent amount in just the last 17 years.

Before the industrial revolution, the natural level of atmospheric CO₂ during warm interglacials was around 280 ppm. The frigid ice ages, which caused kilometre-thick ice sheets to build up over much of North America and Eurasia, had CO₂ levels of around 180 ppm.

Burning fossil fuels, such as coal, oil and gas, takes ancient carbon that was locked within the Earth and puts it into the atmosphere as CO₂. Since the humans have burned an enormous amount of fossil fuel, causing atmospheric CO₂ and other greenhouse gases to skyrocket.

In mid-2017, atmospheric CO₂ now stands at 409 ppm. This is completely unprecedented in the past 800,000 years.

The massive blast of CO₂ is causing the climate to warm rapidly. The last IPCC report concluded that by the end of this century we will get to more than 4℃ above pre-industrial levels (1850-99) if we continue on a high-emissions pathway.

The three-minute story of 800,000 years of climate change with a sting in the tail
How fast are CO₂ levels rising? Credit: Ben Henley and Nerilie Abram

If we work towards the goals of the Paris Agreement, by rapidly curbing our CO₂ emissions and developing new technologies to remove excess CO₂ from the , then we stand a chance of limiting warming to around 2℃.

The fundamental science is very well understood. The evidence that climate change is happening is abundant and clear. The difficult part is: what do we do next? More than ever, we need strong, cooperative and accountable leadership from politicians of all nations. Only then will we avoid the worst of and adapt to the impacts we can't halt.


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The science of carbon dioxide and climate

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Jun 13, 2017
yet the temperature hasn't gone up in 22 years...

Jun 13, 2017
I see the ignorant brigade has arrived.

Jun 13, 2017
Can we all at least agree, regardless of the influence, that pollution is bad?

Jun 13, 2017
But it's also true that since the industrial revolution, CO₂ levels in the atmosphere have climbed to levels that are unprecedented over hundreds of millennia.


But it's also true that the records cannot show whether there have been similiar spikes of CO2 before, because ice is not completely impermeable to gasses, so the amount trapped inside the ice cores is an average over many decades, and the record gets smeared by diffusion of the gasses anyhow as the ice compresses under its own mass, maybe even turning to liquid at places so the actual resolution may be hundreds or thousands of years.

So it's actually rather disingenuous to make the claim based on the available data. You simply don't know whether there's a similiar spike associated with every ice age cycle.

Jun 13, 2017
Not only the ignorance brigade, but the learned anti-science spin squad is present as well.

CO2 is rising 59x faster than natural emissions. Our species evolved during an ice age with 180ppm - 280ppm lower and upper bounds. That environment is gone beyond recall. It amazes me that these comments follow that article at a time when another large ice shelf is about collapse in the Antarctic and every other article here provides dire warnings.

Jun 13, 2017
yet the temperature hasn't gone up in 22 years...
Be nice if you supplied some support for that interesting assertion.

Jun 13, 2017
CO2 magically rises then magically falls?
Earths Axis tilt controls CO2 levels, it's that simple.
If CO2 was the controller "Driver" of temp why do temperature drop with high CO2 or why do temps rise with the lowest levels of CO2
@200 ppm how does CO2 cause rising temps?

Global warming pause 'central' to IPCC climate report
But many governments are demanding a clearer explanation of the slowdown in temperature increases since 1998.
http://www.bbc.co...24173504

Jun 13, 2017
A new paper in a prestigious journal proves a 15-year hiatus in global warming. Why is it being ignored?
https://blogs.spe...bout-it/

Jun 13, 2017
The three-minute story of 800,000 years of climate change with a sting in the tail

It only takes three minutes because apparently all the climate change has happened within the last few decades...

Jun 13, 2017
Earths Axis tilt controls CO2 levels, it's that simple.
Do you have any support for that assertion? Have you read anything on Milankovich cycles? You may want to try doing some reading. It is not just about the Axis tilt - it is way more complicated than that.

Jun 14, 2017
A new paper in a prestigious journal proves a 15-year hiatus in global warming. Why is it being ignored?
https://blogs.spe...bout-it/


Because it ended in 2014, has since mostly been explained by a complex range of factors (such as C02 being absorbed by the ocean etc.) and because the overall warming trend has not changed but has kept track with rising levels of C02.

Jun 14, 2017
yet the temperature hasn't gone up in 22 years...


User name as intelligent as the comment. Fecal regurgitation at its finest.

Jun 14, 2017
Global warming pause 'central' to IPCC climate report
But many governments are demanding a clearer explanation of the slowdown in temperature increases since 1998.
http://www.bbc.co...24173504
Hiatus Hiatus Hiatus.

Jun 14, 2017
bschott
Yes, we have directly measured the CO2 content of the ocean and found it to be rising....oh wait...no we didn't, but we can still say it like we did.


https://www.scien...e-ocean/

Jun 14, 2017
@bschott

[Antarctic sea ice is at an all time high.


No, second lowest!

ftp://sidads.colo...2.1.xlsx

Jun 14, 2017
@full-of-BS
Thank you for confirming that there actually is NO direct measurement of CO2 in the ocean...
sigh

so your comment about there being "NO direct measurement of CO2 in the ocean" is a load of horse manure because your alternative facts are coming from biased anti-AGW sites and not the science

one reason for my continued admonishment to ignore the blogs and sites and concentrate on the science - google scholar is your friend
The collection of extensive, reliable, oceanic carbon data was a key component of the Joint Global Ocean Flux Study (JGOFS) and World Ocean Circulation Experiment (WOCE) and continues to be a cornerstone of the global climate research effort.
http://www.oceand...1329/249

so, you can see we've had a best practice guide since 1994, and to get that it requires a lot of research and data to confirm it's validity

Jun 14, 2017
@full-of-BS cont'd
Yes, we have directly measured the CO2 content of the ocean and found it to be rising....oh wait...no we didn't, but we can still say it like we did
funny thing: i just typed in "ocean measure CO2" and i was rewarded with About 112,000 results (0.11 sec), including Joint Global Ocean Flux Study (JGOFS) and World Ocean Circulation Experiment (WOCE)

your problem is you're working under the ASSumption that your information recieved from your anti-AGW sites is factual, whereas a basic 2 second search in any reputable journal shows you're ignoring the science

.

all four of your posts in this thread have one thing in common: they're based upon your belief

so if you want to make a point against the science, you must first be aware of the science
you repeated the same claim twice in successive posts that is debunked by a cursory inspection, yet you depict it as valid fact

that is called fanaticism, not fact

Jun 14, 2017
PS @ bs -
and that you are using an increase in acidity as an inferred indication of increased CO2 uptake
just FYI, perhaps you should read the data and research

also note: the references that began the guide for JGOFS and WOCE started prior to 1967

that means there have been direct sampling and measurement of oceanic CO2 and other gasses, materials and sampling since at least the publication of the journal references in 1967, and definitely before that as publication would require a firm basis for statistical analysis and peer review

but that is just basic logic speaking...

perhaps that isn't covered in your biased sites considering that so many people are falling for the BS being touted on those sites

deniers are usually:
1- politically or religiously maladjusted (fanatical, selectively delusional)
2- outright cranks (conspiracist ideation, new age, pseudoscience advocates)
3- ignorant and/or stupid

which one are you?

Jun 14, 2017
bschott
Thank you for confirming that there actually is NO direct measurement of CO2 in the ocean
And where does the article say there is a 'direct' measurement of C02? It does say
As the planet began to cool, more CO₂ dissolved into the oceans
It is understood that atmospheric C02 does dissolve into the ocean - and causes the acidity level to change. There is a primer on this site that will help you - https://www.scien...ed-gases
It is becoming more and more clear that the deniers are actually really really ignorant - but consider themselves highly informed.

Jun 15, 2017
It doesn't moron
Wow - sophisticated response here - you are impressing everyone with your giant intellect.
You said
Yes, we have directly measured the CO2 content of the ocean and found it to be rising....oh wait...no we didn't, but we can still say it like we did.
But nowhere in the article does it say or imply that we "directly measured the C02 content of the ocean." So your comment was wrong - and childish. I did then offer a link - that shows that we do measure the ph of the ocean - and understand that it is changing - and a major factor in that change - is the absorption of C02 from the atmosphere. So why not stop being childish - talking about who is the most stupid - and recognize that it is you who are wrong. I will close with a quote from the link I offered before - that was intended to nudge you in the direction of learning. That one failed!!! https://www.scien...e-ocean/ cont

Jun 15, 2017
CO2 plus H2O ---> H2CO3
H2CO3 - carbonic ACID

Jun 15, 2017
cont
That careful balance has survived over time because of a near equilibrium among the acids emitted by volcanoes and the bases liberated by the weathering of rock. The pH of seawater has remained steady for millions of years. Before the industrial era began, the average pH at the ocean surface was about 8.2 (slightly basic; 7.0 is neutral). Today it is about 8.1.

Jun 15, 2017
bschitt - clueless AND insistent.

Jun 15, 2017
BB
Ojorf said it
Wow - what a claim. Here is what Oforf said.
Because it ended in 2014, has since mostly been explained by a complex range of factors (such as C02 being absorbed by the ocean etc.) and because the overall warming trend has not changed but has kept track with rising levels of C02


That in now way says or implies that we are somehow 'directly' measuring C02 levels in the ocean.
Again - here is what you said
Yes, we have directly measured the CO2 content of the ocean and found it to be rising....oh wait...no we didn't, but we can still say it like we did.


So whether you are saying that Ojorf implied we are somehow directly measuring C02 in the oceans - or that this article made that assertion - either way you are wrong. And then throw around childish nonsense like this
If you were sophisticated, I would converse with you in that manner,
Wow....

Jun 15, 2017
BB - now I see what you did. Your read Ojorf this way
and because the overall warming trend has not changed but has kept track with rising levels of C02 in the oceans

I read it the way I think it was meant - which is this way
and because the overall warming trend has not changed but has kept track with rising levels of atmospheric C02

Maybe if instead of pulling out the sarcasm card so quickly - you could have asked Ojorf to clarify. The sentence seems very clear to me - that Ojorf is referring to the "overall warming trend - relating to rising levels of atmospheric C02 - which of course is validated by the evidence.

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