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What’s the hottest the Earth’s ever been?

58 points| throwaway2474 | 4 years ago |climate.gov

64 comments

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gorpovitch|4 years ago

It is interesting to keep these numbers in mind, but these facts are not sufficient to think correctly about climate.

The earth is a dynamic system, and the rate of temperature growth is as much, if not more, important than temperature average here. A car going from 100 to 0 kmph in 15 seconds is definitely not the same as a car going from 100 to 0 kmph in 0.1 seconds in terms of damage.

the temperature rises described in the article (e.g. during the eocene) are about a few degrees every few hundreds of thousands of years. Flore and fauna had time to evolve.

Today we are talking about 4 degrees in less than a hundred years. That's more than thousand times faster.

dalmo3|4 years ago

Without any knowledge in the field I wonder if the timescale difference could be attributed to the measurement methods used for the last centuries vs literal ages ago.

I.e. if we (or someone a million years from now) tried to estimate the 21th century's temperatures using the same techniques used to estimate temperatures a million years ago, would we be able to detect that 4 degree change?

Conversely, can scientists today detect or rule out that there was an outlier century a million years ago in which temps varied as much as today?

Helmut10001|4 years ago

It is strange why many politicians and countries (Germany included) appear to close their eyes and still promote or work on the 1.5 °C goal, which seems pretty unrealistic at this stage. Maybe it is to calm the public, besides knowing better.

Instead, there is a need for more realistic plans to model and prepare for 3°C or 5°C increase of average temperature by 2060 (or 2100). Looking at these bigger swings in temperature, it is more likely that we're seeing temperature peaking beyond our expectations than below.

samwillis|4 years ago

Trouble is most politicians are incentivised to think in the short term and are increasing just in a perpetual campaigning mode. They are thinking about their careers and re-election. They cannot except and talk about bad news, and a 3-5degC increase is bad news.

On top of that you have had climate activists pushing for very large change to happen incredibly quickly (arguably needed). But it’s an incredibly hard sell to the public who won’t except a negative impact on their quality of life.

Basically:

1. People are unwilling to make changes that they perceive as being a net negative to their quality of life.

2. Businesses are unwilling to make changes that they expect to have a net negative to their bottom line.

3. Politicians are unwilling to ask for either of the above to happen because they want to be re-elected.

moralestapia|4 years ago

The thing is that, for businesses and governments, complying with the 1.5ºC goals/projections is already a monumental task. If it does happen, even though it won't be enough, we should at least get an A for effort ... too bad nature is not forgiving.

Anyway, what is still nice is that it should be easier to adapt to 3-5ºC once we're all doing something for 1.5ºC than if we were doing nothing at all, i.e. static friction is always higher than kinetic friction. I think the true covert goal at the moment is to at least get things moving and have everyone jump on it asap.

Source: I build/code software related to sustainability.

vixen99|4 years ago

Which data sources have persuaded you that the realistic and likely increases of 3 or 5 degrees are more probable?

"In 1979, the Charney Report from the US National Academy of Sciences suggested that ECS was likely somewhere between 1.5C and 4.5C per doubling of CO2. Nearly 40 years later, the best estimate of sensitivity is largely the same. This has led some to question why there has been so little progress on estimating climate sensitivity."

Is this quote above now no longer true? If not, please provide a link.

CJefferson|4 years ago

I can't imagine anything most countries could reasonably do to prepare for 5c, what type of things would you suggest?

goodguyamericun|4 years ago

Except Biden has stationed troops halfway across the world and if the MIC gets its way, we might get to pre 1800 levels of temperature, so, thanks Biden I guess. Let's go Biden

matkoniecz|4 years ago

During Hadean geologic eon, when Earth surface was molten and cooled to form the first rocks.

https://en.wikipedia.org/wiki/Hadean

bcraven|4 years ago

Yes, the article acknowledges that but also makes the point that it's not interesting from a human perspective.

"None of these techniques help with the very early Earth. During the time known as the Hadean (yes, because it was like Hades), Earth’s collisions with other large planetesimals in our young solar system—including a Mars-sized one whose impact with Earth likely created the Moon—would have melted and vaporized most rock at the surface. Because no rocks on Earth have survived from so long ago, scientists have estimated early Earth conditions based on observations of the Moon and on astronomical models. Following the collision that spawned the Moon, the planet was estimated to have been around 2,300 Kelvin (3,680°F)."

"Even after collisions stopped, and the planet had tens of millions of years to cool, surface temperatures were likely more than 400° Fahrenheit. Zircon crystals from Australia, only about 150 million years younger than the Earth itself, hint that our planet may have cooled faster than scientists previously thought. Still, in its infancy, Earth would have experienced temperatures far higher than we humans could possibly survive."

"But suppose we exclude the violent and scorching years when Earth first formed. When else has Earth’s surface sweltered?"

melling|4 years ago

“For most of the time, global temperatures appear to have been too warm (red portions of line) for persistent polar ice caps. The most recent 50 million years are an exception”

egberts1|4 years ago

Our Sun probably ate a planet thereby disrupting the solar cycle.

mrlonglong|4 years ago

Interesting article, but one thing let it down, it didn't give the Celsius equivalent for the temperatures quoted in Fahrenheit, I think it would have been nice to have those in brackets for those who can't quite make the mental contortions converting from one to the other. Apart from that quite fascinating to see that life did find a way to exist in temperatures higher then today or in the past.

egberts1|4 years ago

I often wonder about terraforming (on places like Mars planet).

Earth obviously had the leg up on water accumulation during its accretation stage (Hadean period).

Perhaps we can start generating oxygen early over there on Mars using a one-step CO2->O2+C catalyst.

This comes to mind: https://www.pnas.org/content/109/39/15606

isoprophlex|4 years ago

There's like... six millibars of pressure on mars? Admittedly almost all of those six millibars are CO2, but still. Turning all that into O2 might still not support ~photosynthesis~ bootstrapping plant life, let alone humans breathing.

Edit: also sorry to be a party pooper but I studied organocatalysis for a while and you must understand that these research papers about catalysts are almost always so incredibly far away from industrial viability. The ligands take long to prepare, the metals are expensive... and whilst these things might be solvable with enough money, the fact remains that they have turnover numbers that are finite.

(The TON is the amount of substrate the catalyst can transform before becoming deactivated)

Even with a TON of 1.000 (paper quotes < 10) you'd be able to produce 1.000 moles (32 kg) of O2 from one mole (has 100 g Ru, 2000 USD) of this expensive ruthenium gizmo. Oh and it's an electrocatalyst so better get some planet-scale power generation in place, first.

skywal_l|4 years ago

I wonder if terraforming is possible, not because of technological limitations but just because of the limitation of humanity's ability to execute such large scale projects.

Given an unlimited amount of raw materials and energy, terraforming a planet like mars would probably take decades (centuries?).

Private funded projects usually have a TTL of a couple of months to at best 4/5 years and are driven by short to medium term profits. Public funded projects are on a longer timeframe. Taking a recent example, according to Wikipedia, "serious planning" for James Webb started in early 90s. So that's ~30 years.

But do we have example, in modern times, of project lasting more than a century? I have Notre-Dame in mind, any other? The construction of Notre-Dame was driven by religious fervor. I wonder if we could muster the same amount of will based only on a profit motive.

tomaskafka|4 years ago

Perhaps we'd better make sure we try to terraform Earth, as it's much closer to being liveable, than Mars.

Colonizing Mars is like the whole 'I can't bother to learn Bash, so let's rewrite our whole app to Kubernetes in next 5 years' thing. A procrastination.

andrekandre|4 years ago

even if we could generate oxygen, isnt the gravity on mars not strong enough for normal human development?

MichaelZuo|4 years ago

On the positive side of things, northern cities of the world will likely not be buried under an ice sheet anytime soon.

tim333|4 years ago

I like to see stuff like this published that gives some hope that a bit of warming in the next century or two is probably not going to lead to a "we're all going to die" situation.

cable2600|4 years ago

During the age of dinosaurs it was hotter than it is now.

beowulfey|4 years ago

Yes, we live in a relatively cold era in the history of our earth. It’s a great, very informative article.

tamaharbor|4 years ago

Instead of trying to stop the changes (which is probably impossible), why don’t we focus on adapting to what will inevitably become the new normals.

Tagbert|4 years ago

The efforts are to reduce the degree of change. Full on stop is not likely at point. Adaptation will be even more expensive, but we still get people complaining that efforts to head off climate change are too expensive.

iqanq|4 years ago

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