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I am not skeptical of the basic climate science that man is causing most of the recent warming.
I am skeptical though of the accuracy of climate models as of now. I think results speak volumes. And since climate modeling deals with long time periods, we just don’t have enough successful samples. In fsct we don’t even really have one yet, if we consider about 50 years to be a minimal sample size of model prediction is success.
I would like to see at minimum 4 or 5 successful 50 year periods of reasonably accurate model predictive success to be confident Thst models have a handle on things.
The short term success of models so far is ok. But from past reading the error range was pretty wide. So that takes away from usefulness obviously.
I know they plug models in for the past and all, that just doesn’t give me confidence.
Where did I deny that?You should probably provide a link for your assessment of models. The models have actually performed quite nicely to date. Here's my source...
So... You want to see 200+ years of accurate model predictions before you trust them?I would like to see at minimum 4 or 5 successful 50 year periods of reasonably accurate model predictive success to be confident Thst models have a handle on things.
First of all, you really need to expand a bit more on this. Which models are you looking at? There are a number of different models, each with its own parameters. You can even run some of them on your home computer (e.g. EdGCM).The short term success of models so far is ok. But from past reading the error range was pretty wide.
They're talking about using data from the past 60 years to verify current models.There are 60 year old climate models that are accurate?
The article didn’t show the original graph of projections from this 50 year old model or cite its uncertainly range.They're talking about using data from the past 60 years to verify current models.
Scientists test climate models by comparing them to current observations and historical changes. Confidence in these models is based, in part, on how well they reproduce these observed changes. Climate models have proven remarkably accurate in simulating the climate change we have experienced to date, particularly in the past 60 years or so when we have greater confidence in observations (see CSSR, Ch. 4.3.1). The observed signals of a changing climate continue to become stronger and clearer over time, giving scientists increased confidence in their findings even since the Third National Climate Assessment was released in 2014.
Today, the largest uncertainty in projecting future climate conditions is the level of greenhouse gas emissions going forward.
(Emphasis added)
The earliest climate model was developed in 1967, and yes it was fairly accurate.
The First Climate Model Turns 50, And Predicted Global Warming Almost Perfectly
Where did I deny that?
Overview - Fourth National Climate Assessment
Confidence in these models is based, in part, on how well they reproduce these observed changes. Climate models have proven remarkably accurate in simulating the climate change we have experienced to date, particularly in the past 60 years or so when we have greater confidence in observations (see CSSR, Ch. 4.3.1). The observed signals of a changing climate continue to become stronger and clearer over time, giving scientists increased confidence in their findings even since the Third National Climate Assessment was released in 2014.
The uncertainty of ECS has almost nothing to do emissions scenarios, and is mostly because of our poor understandingSecond, it's not an "error range." It's an uncertainty range. Meaning they are fairly certain about most aspects, and some (notably cloud formation) introduce some variability. The uncertainties are fairly small; in fact, the biggest variation isn't due to a lack of understanding, it's a result of different emissions scenarios (i.e. what humans will do).
It is believed that the overall effect of the feedbacks amplifies the temperature increase to 1.5 to 4.5°C.
A significant part of this uncertainty range arises from our limited knowledge of clouds and their interactions with radiation.
I am not skeptical of the basic climate science that man is causing most of the recent warming.
I am skeptical though of the accuracy of climate models as of now. I think results speak volumes. And since climate modeling deals with long time periods, we just don’t have enough successful samples. In fsct we don’t even really have one yet, if we consider about 50 years to be a minimal sample size of model prediction is success.
I would like to see at minimum 4 or 5 successful 50 year periods of reasonably accurate model predictive success to be confident Thst models have a handle on things.
The short term success of models so far is ok. But from past reading the error range was pretty wide. So that takes away from usefulness obviously.
I know they plug models in for the past and all, that just doesn’t give me confidence.
I am not skeptical of the basic climate science that man is causing most of the recent warming.
I am skeptical though of the accuracy of climate models as of now. I think results speak volumes. And since climate modeling deals with long time periods, we just don’t have enough successful samples. In fsct we don’t even really have one yet, if we consider about 50 years to be a minimal sample size of model prediction is success.
I would like to see at minimum 4 or 5 successful 50 year periods of reasonably accurate model predictive success to be confident Thst models have a handle on things.
The short term success of models so far is ok. But from past reading the error range was pretty wide. So that takes away from usefulness obviously.
I know they plug models in for the past and all, that just doesn’t give me confidence.
The article provides a link to the original paper.The article didn’t show the original graph of projections from this 50 year old model or cite its uncertainly range.
Do you have that available?
Except the numbers do not match up.The article provides a link to the original paper.
https://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(1967)024<0241:TEOTAW>2.0.CO;2
The article also describes and assesses the prediction:
"According to our estimate, a doubling of the CO2 content in the atmosphere has the effect of raising the temperature of the atmosphere (whose relative humidity is fixed) by about 2 °C."
What we've seen from the pre-industrial revolution until today matches that extremely well. We haven't doubled CO2, but we have increased it by about 50%. Temperatures, going back to the first measurements of accurate global temperatures in the 1880s, have increased by nearly (but not quite) 1 °C.
I do not see any indications that they actually tried to quantify the uncertainties.
I'm a skeptic because the facts as I know them indicate that there have been at least 6 catastrophic climate reversals over the life of the earth, and not one since man became a factor. So logic tells me it must be something else.
There's also the fact that far to many of these doomsday dates and catastrophic results have not happened.
I'm not sure what your question is referring to, but I was responding to your comment ---
"I am skeptical though of the accuracy of climate models as of now"
That's why I posted the reference from the 4th NCA, which talks about the accuracy of the models. Thanks...
So you want to wait until it happens before you believe it?
Interesting approach. Hey, what could go wrong?
I didn’t spot a graph on there giving future temperature projections.The article provides a link to the original paper.
https://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(1967)024<0241:TEOTAW>2.0.CO;2
The article also describes and assesses the prediction:
"According to our estimate, a doubling of the CO2 content in the atmosphere has the effect of raising the temperature of the atmosphere (whose relative humidity is fixed) by about 2 °C."
What we've seen from the pre-industrial revolution until today matches that extremely well. We haven't doubled CO2, but we have increased it by about 50%. Temperatures, going back to the first measurements of accurate global temperatures in the 1880s, have increased by nearly (but not quite) 1 °C.
I do not see any indications that they actually tried to quantify the uncertainties.
But there is an established track record of successful cancer predictions. So I would be pretty confidence in a diagnosis. There is no track record yet for multi decade climate(at least 5 decade) predictions.If you want to wait that long, you may have more evidence than you may be comfortable handling. It's a little like someone hearing that they have cancer and without treatment they will die in the next year, and saying they want to wait a few years to be sure the doctors know what they are talking about before doing anything about the cancer.
Well, lots could go wrong. But I want base my concern on tested models, not reasonable theory. The theory is reasonable, and likely true, but how true? If it turns out to be the low end, it’s not worthy of much concern.
"The science linking human activities to climate change is analogous to the science linking smoking to lung and cardiovascular diseases. Physicians, cardiovascular scientists, public health experts and others all agree smoking causes cancer," the AAAS wrote in its report, "What We Know."
"And this consensus among the health community has convinced most Americans that the health risks from smoking are real. A similar consensus now exists among climate scientists, a consensus that maintains climate change is happening, and human activity is the cause, and is potentially too dangerous to continue to ignore."...
The AAAS says there is scarcely any precedent for the speed at which this is happening: "The rate of climate change now may be as fast as any extended warming period over the past 65 million years, and it is projected to accelerate in the coming decades."
Historically rare extreme weather like once-in-a-century floods, droughts and heat waves could become almost annual occurrences, it says. Antarctic and Greenland ice sheets could see large-scale collapse, the Gulf Stream could alter its course, the Amazon rain forest and coral reefs could die off, and mass extinctions could threaten ecosystems.
Climate Risks as Conclusive as Link between Smoking and Lung Cancer - Scientific American
I am not skeptical of the basic climate science that man is causing most of the recent warming.
I am skeptical though of the accuracy of climate models as of now. I think results speak volumes. And since climate modeling deals with long time periods, we just don’t have enough successful samples. In fsct we don’t even really have one yet, if we consider about 50 years to be a minimal sample size of model prediction is success.
I would like to see at minimum 4 or 5 successful 50 year periods of reasonably accurate model predictive success to be confident Thst models have a handle on things.
The short term success of models so far is ok. But from past reading the error range was pretty wide. So that takes away from usefulness obviously.
I know they plug models in for the past and all, that just doesn’t give me confidence.
Yes, but we have a long track record of people smoking and getting cancer.The scientific community is warning us the dangers are too high to ignore. It's like a doctor telling a patient who is a smoker that the risks are continuing to smoke are just too high. Do they know if the patient is going to get cancer tomorrow or in 5 decades. They probably can't. But they would issue a strong caution. Here, too, they are telling us they are as confident telling us about the risks of climate change as they are of the cancer risks of smoking.
For the most part, The value of the climate's response to added CO2 is not based on time.I didn’t spot a graph on there giving future temperature projections.
So the future prediction is tied to how long it takes to cause then doubling of CO2, not the effect.If the amount of carbon dioxide were doubled instantaneously,
with everything else remaining the same, the outgoing infrared
radiation would be reduced by about 4 Wm-2. In other words, the
radiative forcing corresponding to a doubling of the CO2 concentration
would be 4 Wm-2. To counteract this imbalance, the
temperature of the surface-troposphere system would have to
increase by 1.2°C (with an accuracy of ±10%), in the absence of
other changes. In reality, due to feedbacks, the response of the
climate system is much more complex. It is believed that the
overall effect of the feedbacks amplifies the temperature increase to 1.5 to 4.5°C.
A significant part of this uncertainty range arises from our limited knowledge
of clouds and their interactions with radiation.
So you want to wait until it happens before you believe it?
Interesting approach. Hey, what could go wrong?
Yes... that's because... you can make predictions... without graphs.I didn’t spot a graph on there giving future temperature projections.
Yes, we do. I literally just pointed you to a paper from 1967 that made a fairly accurate prediction.Yes, but we have a long track record of people smoking and getting cancer.
We don’t have a long track record of successful multi decade (at least 5 decade) climate predictions.
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