How Climate Scientists Predict The Future

Submitted by: fancylad 4 weeks ago in Science


Scientists have made a lot of predictions about how Earth's climate is changing, but they don't just pull those predictions from thin air.
There are 21 comments:
Male 3,803
Lets see how next years hurricane season goes.
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Male 41,576
kalron27 I'd say the next 9-10 to be fair eh?

 Since they've been 100% dead wrong the past 12 years? It would take 10 sequential years to make up for that I think. (this year counts as 1) Call me when the next 10 years 'proves them right' ok? ;-)
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Male 56
This guys makes a few totally wrong statements.  A more complex model does not necessarily make a more accurate future prediction compared to a simple model.  Also, if a model matches closely to historical data, that doesn't necessarily translate into that model accurately predicting future conditions.

Probably one of the best reports written on this topic is here.  https://pubs.usgs.gov/sir/2010/5211/pdf/uncpest_sir2010-5211.pdf.  Unfortunately, you likely won't be able to understand much of the report unless you are a mathematician (or at least got an A in you college linear algebra class)  However a good summary is the graph on page 10.  The X-axis shows increasing model complexity and the Y-axis shows model prediction error.  You notice that prediction error starts to spike exponentially once models get too complex.  If you actually ran an analysis like this on most global climate models, I suspect that we would find that we are in the "way too complex" range.

I am about as far from a "climate change denier" as you can be.  I mean you can't argue with historical data (well technically you can, but only within measurement uncertainty).  However, lately I am increasingly bothered about how our advances in numerical modeling (mostly just due to faster computers) have way outpaced our advances in actual science.
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Male 485
Tatung42 "However, lately I am increasingly bothered about how our advances in numerical modeling (mostly just due to faster computers) have way outpaced our advances in actual science."
That's a good point. Soon enough machine learning will yield much better prediction of climate change (Machine learning in geosciences and remote sensing). Yet, that doesn't mean scientists will understand what is actually happening. 
But I think the bigger disconnect is between what the climate scientists know and what the general public knows, which is only made worse by lack of trust in the scientific community. 
I think the maker of the video is aware what you're calling "totally wrong." This video is aimed at the general public, so they don't go into errors/confidence intervals. My guess is a model that had unacceptably high error rate due to accounting for too many variable, that model would be deemed inaccurate. And a good model at least has to be able to pass the hindcasting test - i don't see where the video says that science stops there.
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Male 485
Don't rely on media's interpretation of scientific findings - they often overstate or misrepresent the science. If you can, try to get information from scientific papers, or articles that cite scientific papers.

https://skepticalscience.com/ is a good place to start to learn more about climate science. 
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Male 2,717
"More and Stronger Storms" does sound sensational, eh?

"...As a result, global warming may cause the temperature difference between the poles and the equator to decrease. and as the difference decreases, so should the number of storms, says George Tselioudis, a research scientist at NASA Goddard Institute for Space Studies (GISS) and Columbia University...But even as a warming climate might decrease the overall number of storms that form, it could increase the number of intense storms." link

From Skeptical Science:

"And to cap it off, two recent peer-reviewed studies completely contradict each other. One paper predicts considerably more storms due to global warming. Another paper suggests the exact opposite – that there will be fewer storms in the future.

What can we conclude from these studies? About hurricane frequency – not much; the jury is out, as they say. About climate change, we can say that these differing approaches are the very stuff of good science, and the science clearly isn’t settled!" link
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Male 357
boredhuman I always thought science needs pr people. They put out good work that makes perfect sense to those in their field but those outside the field grab on to things and blow them out of perportion.
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Male 41,576
Prediction about 13 years ago: MORE storms STRONGER storms.
Past 12 years? ZERO strong storms made landfall. ie: reality was less storms and weaker ones. 
But we can totally believe them now! Because ONE year makes everything they predicted true.
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Male 1,089
5cats https://en.wikipedia.org/wiki/Atlantic_hurricane_season#2010s

Also, you aren't fooling anyone. The landfall distinction is a red herring and even your dumber friends know that. More stronger storms don't mean more storm landfall

https://earthobservatory.nasa.gov/Features/ClimateStorms/page2.php.
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Male 357
marsii Give it up. This is an example of why education is being attacked. If they can keep people dumb then they can keep trotting out these half truths.
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Male 41,576
marsii Ok, look, this is really simple:
Until satellites? Super-accurate measurements of storms out at sea weren't possible. Now they are, so naturally since the 70's 'more big storms' will be recorded because they are measured far out at sea.
However? Highly accurate storm records for those which make landfall in the USA and many other nations have existed for centuries. Precise wind speeds, rainfall, pressures and all the rest all carefully recorded.

To compare apples to apples? One MUST compare landfall to landfall. Period, end of discussion.
What damage to 'at sea' storms do? Not a hell of a lot, except for a few very unlucky boats. The REAL damage happens when... they make landfall! THAT is what matters here.

And the AGW predictions specifically said LANDFALL. That more and stronger would make landfall in the USA... but they did nothing like that. It was the longest strong-storm free period in recorded US history. 

https://www.usatoday.com/story/weather/2014/05/14/hurricane-hiatus-usa-florida/9000343/

No 'major' (Cat-3 or above) hurricane made landfall on the USA between this year and Wilma in 2005. Ok? Apples to apples. There were 4 (iirc) major storms in 2005 and the AGW said MORE AND STRONGER making landfall... and for 12 years: nothing. Fewer and weaker.
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Male 485
5cats "Super-accurate measurements of storms out at sea weren't possible."
Have you heard of the Hurricane Hunters? - Airplanes flying into storms starting in 1940s: "The Hurricane Hunters gathered data from a storm's innards, including pressure readings and measurements of wind speed and direction." What makes you say accurate measurements of sea based storms weren't possible after 1940s?
It's true that there hasn't been an increase in the number of storm/hurricanes in the world. 

There's no question that the costs due to natural disasters, especially hydrological events, has risen dramatically. There are many factors - it's not proof that storms have gotten stronger, of course.

"AGW predictions specifically said LANDFALL" - where did you see this?

I suggest you take a look at this FAQ by MIT professor K. Emanuel:
"3.) Q: Is the intensity of hurricanes increasing with time? A: There is some evidence that it is. Records of hurricane activity worldwide show an upswing of both the maximum wind speed in and the duration of hurricanes. ...
8.) Q: I gather from this last discussion that it would be absurd to attribute the Katrina disaster to global warming?
A: Yes, it would be absurd."

If you'd like to get much deeper understanding, watch Cornell University: How Hurricanes Respond to Climate Change
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Male 41,576
boredhuman Those planes were there in the 1880's? No? Then my case remains valid. I specifically said "centuries" plural... but there's landfall records going way back and they are very accurate.

There were some accurate measurements for storms at sea, but certainly not for every hour of every storm eh? Individual ships with no means of communication would keep their journals very well. But while trying to flee the storms, not monitor them :p

If they didn't say 'make landfall' (and they all did) then they'd be utterly meaningless and still wrong! There were BY FAR fewer and weaker during that 12 year span compared to the previous 12 years, or almost any given 12 years on record. The 1800's had more, stronger hurricanes in 3 or 4 of their decades than in modern times. Making landfall that is, of course. 
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Male 485
5cats C'mon, you gotta take credit for the confusion. You specifically mentioned 70s.. oh wait, you implied 1870s? - my fault!
"Until satellites? Super-accurate measurements of storms out at sea weren't possible. Now they are, so naturally since the 70's 'more big storms' will be recorded because they are measured far out at sea."

All kidding aside, you make a valid point: On Estimates of Historical North Atlantic Tropical Cyclone Activity
"In this study, an estimate of the expected number of Atlantic tropical cyclones (TCs) that were missed by the observing system in the presatellite era (between 1878 and 1965) is developed."
...
"Overall, our findings suggest that it is possible that Atlantic TC counts may have significantly increased since the late nineteenth century, although the evidence is decidedly mixed, with some other activity measures showing either no change or a decrease with time. Total storms per year and U.S. landfalling activity show no increasing trend, and average TC duration shows a significant decrease over time."


Take THAT 5cats haters!

However, it's more nuanced than "apples to apples... Period, end of discussion."
You can't just look at Continental US Hurricane Landfalls and think you have the global picture.

"It’s important to remember that only 11% of all hurricanes occur in the Atlantic, the rest are in the Pacific and Indian Oceans"
"The energy released by the average hurricane (again considering all hurricanes worldwide) seems to have increased by around 70% in the past 30 years or so, corresponding to about a 15% increase in the maximum wind speed and a 60% increase in storm lifetime." - FAQ by Emanuel

It's complicated. Despite this, there is strong consensus that the frequency of high end hurricanes will go up. 
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Male 41,576
boredhuman Thanks for the effort! Yes I did look at those charts, and the 1800's had quite a lot more strong storms, the "1878" cut-off date excludes some really active decades...

Yes the satellites came in the 1970's and until then there were NOT accurate measurements by the hour of EVERY storm across the Atlantic. Period ok? Planes read them more than before 1940? Sure, but nothing at all compared to after the satellite age began. Thus the apples to apples are required for pre-aircraft (and pre-radio!) readings too! Landfall is the ONLY common measure that matters.

It doesn't matter what OTHER parts of the Earth do, this topic is about (specifically) the USA and the AGW predictions related to it. Well, MY discussion of this topic is anyhow, lolz! In THESE predictions the AGW are 100% wrong, yes? The past 12 years or so have proven that beyond any doubt.

Pacific storms are far less well studied in centuries past. It's a huge area with little or no population or ship traffic before the age of steam...
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Male 8,199
5cats 

Ridiculous claims require ridiculous proof.  I've seen a lot of opinion from you, not much fact.  Back it up.
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Male 41,576
normalfreak2 Suck shit. Refute what I said or go fuck daegog's Mom...
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Male 485
normalfreak2 I've shown that 5cats ' opinions sometimes match facts. I would also love for him to provide proof (links) to his claims. That doesn't mean 5cats can be simply dismissed.
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Male 8,199
boredhuman The pejorative I'd use is to replace "sometimes" is "rarely"
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Male 41,576
boredhuman It does in his mind, he's been that way for years.

And anything I provide? He rejects outright! It doesn't matter if it comes straight from NASA itself, he refuses to believe it if I say it is so. If I make a typo that disproves everything I've ever said on the subject! 

Oh, you are also my sock-puppet too. So says some of the hate-spammer like NF2 eh? 

Just thought I'd explain where my hand is at the moment... it's not what you think! O_o
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Male 1,089
boredhuman He can be dismissed very easily
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