The world has warmed 1.5 °C, according to 300-year-old sponges

https://www.nature.com/articles/d41586-024-00281-8

by tigerlily • 2 years ago

77 49 2 years ago

And yet we are doing better than ever, almost like we can adapt. Maybe the apocalyptic predictions are overblown.

makeworld• 2 years ago

So we have already surpassed 1.5C by this measure, and will pass 2C earlier than predicted. Does that mean the various events predicted to occur around 2C will also occur earlier? Or not, because this paper measures from an early date?

spywaregorilla2• 2 years ago

Earlier date, different baseline. Doesn't really change anything.

onlyrealcuzzo• 2 years ago

Why is warming 1.5C from a prior date not as bad as warming 1.5C from the more referenced date?

We were in an ice age 300 years ago.

The climate has changed a lot compared to an ice age. Is it really going to change even more in the next 0.5C?

TSiege• 2 years ago

It's not so simple. 1.5C was decided on after assuming 2C would be fine after (warranted) political pressure from more at risk countries.

What are the risks is really more about climate sensitivity than a specific temperature, think of it as how much can change given a warming of X degrees. Recently there is growing scientific evidence that dangers we thought were only possible at high temp scenarios, say 3-4C, are possible at 2C or might even be underway. Meaning that the climate is more sensitive than had been projected. This means that not only according to the study linked above are we closer 1.5C + 2C, but we also have more to fear from passing those temps because more can go wrong at lower levels of warming.

Every tenth of a degree matters and we should stop obsessing over 1.5C or 2C and work on mitigating as much as possible and preparing for whats coming and slow emissions and pollution as much as possible

hnthrowaway0328• 2 years ago

Montreal is particularly warm but dry this winter -- actually in many days warmer than Shanghai, China. I hope we don't have a super cold March this year.

SebFender• 2 years ago

Dry? It's been raining like crazy this year...

kjqgqkejbfefn2• 2 years ago

What about this hockey-stick shaped curve ?

https://revistapesquisa.fapesp.br/wp-content/uploads/2019/07...

wolpoli• 2 years ago

That appears to show the position of the magnetic north pole over the years. Does the location of magnetic pole affect local weather conditions?

smashed• 2 years ago

https://climate.nasa.gov/explore/ask-nasa-climate/3104/flip-...

mitthrowaway2• 2 years ago

What about it?

kjqgqkejbfefn2• 2 years ago

See for yourself:

The ‘Sterno-Etrussia’ Geomagnetic Excursion Around 2700 BP and Changes of Solar Activity, Cosmic Ray Intensity, and Climate

https://www.cambridge.org/core/journals/radiocarbon/article/...

The Sterno-Etrussia excursion may have amplified the climate shift, which, in the first place, was the effect of a decline of solar activity. During excursions and inversions, the magnetic moment decreases, which leads to an increased intensity of cosmic rays penetrating the upper atmosphere. Global changes in the electromagnetic field of the earth result in sharp changes in the climate-determining factors in the atmosphere, such as temperatures, total pressure field, moisture circulation, intensity of air flows, and thunderstorm activity. In addition, significant changes in the ocean circulation patterns and temperature regimes of oceans will have taken place.

Global climate change during the 13,500-b.p. Gothenburg geomagnetic excursion

https://www.nature.com/articles/265430a0

ROBERTS and Olsen1 suggested that high latitude atmospheric ionisation has an important role in nucleating cirrus clouds. And Harrison and Prospero2 deduce that, if this is correct, severe drops of the Earth's magnetic field strength, such as are believed to accompany reversals, would lead to increased upper atmospheric cloudiness at all latitudes and correspondingly to major climatic events. There is likely to be warming at high latitudes but considerable cooling in the middle latitudes, in a way analogous to the aerosols3.

Are there connections between the Earth's magnetic field and climate?

https://www.sciencedirect.com/science/article/abs/pii/S00128...

Understanding climate change is an active topic of research. Much of the observed increase in global surface temperature over the past 150 years occurred prior to the 1940s and after the 1980s. The main causes invoked are solar variability, changes in atmospheric greenhouse gas content or sulfur due to natural or anthropogenic action, or internal variability of the coupled ocean–atmosphere system. Magnetism has seldom been invoked, and evidence for connections between climate and magnetic field variations have received little attention. We review evidence for correlations which could suggest such (causal or non-causal) connections at various time scales (recent secular variation ∼ 10–100 yr, historical and archeomagnetic change ∼ 100–5000 yr, and excursions and reversals ∼ 103–106 yr), and attempt to suggest mechanisms. Evidence for correlations, which invoke Milankovic forcing in the core, either directly or through changes in ice distribution and moments of inertia of the Earth, is still tenuous. Correlation between decadal changes in amplitude of geomagnetic variations of external origin, solar irradiance and global temperature is stronger. It suggests that solar irradiance could have been a major forcing function of climate until the mid-1980s, when “anomalous” warming becomes apparent.

Book on the subject: The Hidden Link Between Earth’s Magnetic Field and Climate

https://books.google.fr/books?hl=fr&lr=&id=MeXEDwAAQBAJ&oi=f...

The Role of Geomagnetic Field Intensity in Late Quaternary Evolution of Humans and Large Mammals

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

It has long been speculated that biological evolution was influenced by ultraviolet radiation (UVR) reaching the Earth's surface, despite imprecise knowledge of the timing of both UVR flux and evolutionary events. The past strength of Earth's dipole field provides a proxy for UVR flux because of its role in maintaining stratospheric ozone. The timing of Quaternary evolutionary events has become better constrained by fossil finds, improved radiometric dating, use of dung fungi as proxies for herbivore populations, and improved ages for nodes in human phylogeny from human mitochondrial DNA and Y chromosomes. The demise of Neanderthals at ~41 ka can now be closely tied to the intensity minimum associated with the Laschamp magnetic excursion, and the survival of anatomically modern humans can be attributed to differences in the aryl hydrocarbon receptor that has a key role in the evolutionary response to UVR flux. Fossil occurrences and dung-fungal proxies in Australia indicate that episodes of Late Quaternary extinction of mammalian megafauna occurred close to the Laschamp and Blake magnetic excursions. Fossil and dung fungal evidence for the age of the Late Quaternary extinction in North America (and Europe) coincide with a prominent decline in geomagnetic field intensity at ~13 ka.

Latest Permian and earliest Triassic geomagnetic polarity timescale: A polarity reversal marks the greatest mass extinction

https://www.sciencedirect.com/science/article/abs/pii/S09218...

jmward012• 2 years ago

Global warming is real, but I wish we paid more attention to biodiversity and set goals there instead of fixating on temperature. I understand why temperature is there. It is easy to measure and an easy number to campaign around, but biodiversity, to me, is the actual point and focusing on temperature, while a major factor, diminishes the many other issues attacking it.

vlovich123• 2 years ago

We’re already doing piss poor responding to a simple number that’s super easy to measure and evaluate predictions against. Do you think a harder to measure more argumentative measure would make global warming easier to tackle?

blagie8• 2 years ago

Yes.

jmward012• 2 years ago

It is a really hard problem to survive. The only somewhat successful, so far, long term strategy I know of is the one we see in nature, diversity. Healthy ecosystems are always diverse. Diversity helps absorb shocks and exploit nitches that enable growth. But here is the kicker, diversity is helpful in every system to keep it alive, including the diversity of arguments we use in educating people. By focusing on just one argument we are making a mistake. I'm not saying we throw out temp targets and discussing them, but we need more valid discussions to increase the diversity of the discussion so that it survives and thrives.

xnx• 2 years ago

Agree. Climate change is just one of the ways (and a big one) that habitat is being destroyed. Ocean acidification, conversion of forests and fields to farmland, and fertilizer runoff are others.

orwin• 2 years ago

Climate change and acidification have the same main causes.

tasty_freeze3• 2 years ago

If the message that "Climate change is happening, it will cause starvation, large scale displacement, and regional conflicts, and significant economic disruption" isn't enough to make people take notice, why would "Here is a list of creatures you have never seen in real life and might live on a different continent from you" would have any impact?

sho_hn• 2 years ago

It won't, because many of today's children are already growing up used to the lack of biodiversity . If you're living in a large city, wildlife and insects are things you see on Netflix and in video games and sort of abstractly know are somewhere out there. Maybe.

nine_k• 2 years ago

I would say that the rising level of oceans must be pretty significant for a lot of people, because most people live near a coast. Building a wall to protect NYC or Tokyo from flooding would be quite noticeable and expensive. Flooding a city that fails to handle the rise of the oceans would be even more noticeable.

Biodiversity may eventually become higher with a warmer overall climate, as it has occurred in the past.

donatj• 2 years ago

For the Americans layman like myself, that's a warming of 2.7 °F

blagie8• 2 years ago

Meh, don't care.

Seriously, we had ice ages. Temperatures go up and down.

I can't bring myself to care about 86 instead of 83 degrees F in the summer and 23 instead of 20 in the winter. It's like moving a few hundred miles south. People get by fine.

I mean, I'm worried about all the weird chemicals in my food. That seems kinda wacky. I'm worried about all the biodiversity disappearing. Extreme-weather-itis would be scary, if it's actually a thing. I'm worried about breathing more CO2, and especially about the same in water (ocean acidification). I'm worried about many of the other impacts on climate.

"Climate change" was a step forward in terminology from "global warming," but we need about five more steps before it's something people care about.

We also need to acknowledge how much we don't know. Most of our models from 20 years ago didn't play out, which was obvious if you read the papers instead of listening to Al Gore. Bad things happened, but not the ones we thought would happen. It's a chaotic system. It doesn't work predictably.

MR4D• 2 years ago

Agreed. Many more people will die of heart disease And cancer than from global warming. Too many chemicals in our environment and food chain.

defrost2• 2 years ago

I can't bring myself to care about 86 instead of 83 degrees F in the summer and 23 instead of 20 in the winter.

Respectfully, you've not understood the measure and the meaning of global average.

For most of the past 200K years, most of human 'advanced' existance there's been little change in the global mean and all the seasons have changed as per written history and your recollection.

Lifting the global mean introduces more energy to the climate cells about the globe, driving more extreme changes, intoducing greater storms, setting us up for even more change as water vapor and methane levels rise which themselves are greater insulators that trap more heat than CO2.

blagie8• 2 years ago

driving more extreme changes, intoducing [sp] greater storms

Respectfully, the mean temperature is the wrong measure for that. You want to look at measures like variance / std. div. -- the second moment and not the first.

That's why I listed under "Extreme-weather-itis" under things I care about.

setting us up for even more change as water vapor and methane levels rise which themselves are greater insulators that trap more heat than CO2

Respectfully, you don't know that. The phrase should be "setting ourselves up for something possibly very bad." Extrapolation works worse than interpolation, and it's a chaotic system.

Respectfully, the level of imprecision and propaganda here is a root cause of scepticism.

People can understand why we don't want to play Russian Roulette, especially when most of the barrels are loaded, each with a different munition. That's more honest and likely leads to the outcome you want.

tasty_freeze3• 2 years ago

Ice ages occurred over the span of thousands to tens of thousands of years. The current change is happening in the order of decades to centuries. Not only will plants and animals have a hard time adapting to change that rapid, it will cause huge amounts of misery.

Maybe where you live 83 vs 86 degrees doesn't matter, but there are hundreds of millions of people that are living on the edge already. Once a century droughts are becoming common. When people are fighting for their lives and the lives of their children, they will move anywhere where things are marginally better ... causing economic chaos, and even war. But that doesn't seem to affect you in your air conditioned house.

Most of our models from 20 years ago didn't play out,

That is false. The IPCC reports of 20-25 years ago are wrong only in that they undershot the severity. All of them, for political reasons, knowingly under reported the severity. I agree, don't listen to Al Gore, listen to the climate scientists. BTW, why do you think the paper you are reading is any more informed about climate change than Al Gore?

blagie8• 2 years ago

Ice ages occurred over the span of thousands to tens of thousands of years

See "Little Ice Age" and it's effects.

Once a century droughts are becoming common

"Climate change" not "global warming." On the whole, global warming makes for more rain. You can see another post here about rising atmospheric humidity.

I agree, don't listen to Al Gore, listen to the climate scientists. BTW, why do you think the paper you are reading is any more informed about climate change than Al Gore?

A key difference are things like error bars.

With /proper/ error bars (accounting for all possible sources of error), right-wing media would have a hard time playing back false predictions.

st-keller• 2 years ago

„It's a chaotic system. It doesn't work predictably“ is exactly the thing that worries me most - because that means it could get way worse than predicted today!

blagie8• 2 years ago

Absolutely.

dreamworld• 2 years ago

Temperature increases will be much larger over land. The values are for global averages, and most heat capacity is in the ocean. Not only that but some places will warm far more than others. Yes, all the other stuff is bad too, including ocean acidification. But they're intimately connected, and the rate of temperature change might be one of the largest changes in habitats worldwide.

egberts1• 2 years ago

Incredible sample size for an incredible error rate.

tcfhgj• 2 years ago

why is an article from Nature flagged?

The world has warmed 1.5 °C, according to 300-year-old sponges

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