The question you have to ask is "Are the number of stations used adequate to derive a global temperature?" Evidence suggests it is. In particular I'd like to point out the Berkeley Earth project. They use all available data including over 39,000 unique stations yet their results aren't significantly different than NOAA, NASA and HADCRUT. So I have a hard time dinging NOAA for using a limited number of stations as long as it's statistically justified.
The question I'm asking is if "global" temperature is the right thing to measure?
Can you convert that global temperature into a measure of the earth's heat energy, as a measure of the net energy the earth has retained from sunlight? No.
When heat and radiation energy can be stored as chemical energy and vice versa, there's a lot that we're not measuring that are important factors.
I have not offered a theory. You lack reading comprehension.
Excellent. If you are correct, and greenhouse gases have no warming effect then this is obviously something you have proven experimentally. Cite the relevant paper in which you published your results.
This is a false dilemma. Pointing out that "greenhouse gases cause warming" has insufficient evidence does not require me to take another position.
I do not need to offer the right answer to say that 1+1 = 3 is wrong.
Cite the relevant paper which demonstrates the dependency on the "earths temperature" to prove/disprove the greenhouse gas effect.
Cite the relevant paper that demonstrates that we need to isolate the effect of CO2 to prove/disprove the greenhouse gas effect.
I don't need to cite anything. I am pointing out your logical fallacy. You don't even know how to know truth.
The temperature of the surface of the Earth is well-defined
No it is not. Have you gone outside lately? Walked in the sun, rested in the shade, sat on the grass? Coming up with a single temperature number for 200 million square miles and a corresponding volume is not well defined or even meaningful.
The first thing you need to know about any model is that it's definitely wrong.
The second thing you need to know is that with the right assumptions, you can make the model usefully wrong.
And that's what I'm doing - checking if anyone here actually knows what the assumptions are, and how or why they are right.
When you make a wrong statement like the quoted one above, that's an indication that you don't have the right assumptions, and so your model is uselessly wrong.
Your problem is that you're asking highly technical questions with no short answers on Slashdot, rather than digging into the scientific literature.
"What's a `global temperature'?" is not a highly technical question.
Based on the responses so far, it doesn't actually have any meaning, which makes being concerned about its derivative pointless.
theoretically anyone can do it, but in practice it requires certain skills and a lot of work.
I'm an engineer. I analyze complex systems. The earth is a complex system, and I can understand the techniques being used here enough to know they are inadequate for the stated purpose.
It's more about the balance between incoming solar radiation and outgoing radiation.
So net energy the earth receives from the sun?
This is why I want this explanation. It shouldn't be this hard to find out what we think we're measuring with "global average surface temperature".
No one is collecting global average temperature today. It's a derived number by taking the temperatures from hundreds of separate weather stations. While the coverage was less in the 1880's it was still adequate to derive a global average temperature, just with slightly higher error ranges than current ones.
These are important details for any discussion on this issue, buried in the fine print.
Google says Earth has roughly 200 million square miles of surface area. With hundred of measuring stations, that means each station is responsible for sampling several hundred thousand square miles.
The original question was, "What is global temperature?"
The answer, according to these facts, is an indirect measure of the energy the earth keeps from the sun, using an average extrapolated from hundreds of temperature measurements from the earth's surface, with each sample representing several hundred thousand square miles.
I thank you for actually trying to answer the question; most of the other responses failed at increasing understanding.
It appears that you are confused about the nature of the greenhouse effect (confusing it with greenhouses or some blather about "chemical reactions") which doesn't bode well for proving your theory that increasing the concentration of greenhouse gases leads to zero warming.
"My" theory? Reading comprehension is not your strong suite. I am criticizing your critique of someone else's position.
You inserted your own assumption that so called greenhouse gases must cause some warming effect into his position and treated that as an internal contradiction.
That's nonsense, because it's your assumption. The point about greenhouses is merely that the common words used in this debate are abused beyond their meaning.
Are you able to prove your theory that increasing the concentration of greenhouse gases leads to zero warming? Yes or No?
The ability to measure "earth's temperature" has insufficient precision or accuracy to prove or disprove "zero warming". Never mind that the earth is too complex a system to isolate the effect of CO2.
The Middle east is already extremely hot, and at the edge of human endurance. If, with no other changes, it also had added moisture, the humidity level would rise dramatically. assuming this was stable (and it didn't get driven off by existing patterns), this would raise the total heat index considerably, potentially beyond human inhabitability.
Sure it makes sense. We have additional CO2 in the air, warming the atmosphere. We know this happens. The planet is retaining more heat because of it. Therefore, if the recent temperature rise has nothing to do with CO2, then the additional heat from the CO2 has to be somewhere on the planet, and when that repository gets full we're going to have even more temperature rise.
Circular reasoning. We assume that CO2 raises temperature, so if we don't observe CO2 raising temperature, then CO2 must be raising the temperature somewhere else, even if we fail to observe it.
Transforming your assumptions into dogma is a horrible way to practice science.
Just because measurements aren't accurate doesn't mean they're meaningless.
That is not related to my question. A number is assigned to Earth and the number is shown to change over time. That number doesn't carry it's own meaning. It's the unit that gives it meaning. Now, if there unit were of mass, that'd be straight forward - what's the total mass of earth? If it were of velocity, that's also straight forward enough - where is this big ball of mass going in space and time?
But "global temperature"? That's not straightforward at all. Temperature is volatile and dependent on many factors. Same heat content put into different substances gives you different temperature readings.
Let's say we measured every human's internal temperature and created a global average human temperature- what meaning does that have for earth's global temperature? Not much - humans are warm blooded mammals that regulate their internal temperature, and are only a tiny percentage of the earth's total volume or mass. What you choose to measure changes the meaning of the final number.
If we're consistently measuring the Earth at 0.5C low, then we know what the temperature changes are.
And the number is nonsensical if not properly understood. The temperature swing from morning to night is several magnitudes greater than 0.5C. The temperature swing from season to season is several magnitudes greater than 0.5C.
There is so much innate volatility in a temperature number that the definition of "average" adds a very large number of assumptions that need to be qualified.
Measurement error does seem to be reported. For example, 2014 is the hottest year measured in human times, but the information came with the caveat that the measurement errors are such that it might well not be.
Reported is not the same as verified. When it comes to science, your margin of error matters more than your actual results.
Every unqualified assumption adds error to the results. That's why I'm asking these questions, and the lack of good answers indicates a very, very large margin of error in what is said to be known.
This is prejudice masquerading as science, and people who actually like science should be concerned about this.
I didn't say it was simple. It involved gridded area weighted averages over the whole surface of the Earth.
I didn't say it was simple either. But even complex systems can be described simply. For example, you could say that the global average temperature reflects the net amount of heat the earth traps from the sun.
Is that what it means?
The global average temperatures since 1880 have nothing to do with ice cores, tree rings or other proxies. They're based on thermometer measurements only.
No one was collecting "global average temperature" in 1880. Didn't have the tools or coverage.
What you actually have is "projected global average temperature based on the 1880 temperature measurements we happen to have".
Those 1880 temperature measurements are not made with the same tools or methods as our current measurements 130 years later. We have a lot more research money going into the topic right now. Some of that money ends up in sophisticated new temperature measuring tools which did not exist 130 years ago.
So you have no interest in learning, you just want to ask questions and ignore the answers, hoping that you don't have to think about this any more. Your ignorance, and your acceptance of it, is astounding.
Asking *you* to explain it to me is the opposite of accepting ignorance.
The inability of various responders to provide answers is the actual ignorance.
How hard is it to give a simple answer and then point to an authoritative source? But the simple answer is skipped and the responders hide behind the supposed authority.
It's a simple fact that humans can't survive if the wet bulb temperature is 35C (95F) or greater. If the combination of temperature and humidity reaches that state it's impossible for your body to cool by sweating.
Keyword: "If". None of that is relevant.
Deserts have hot temperatures because they lack water to absorb the heat. A humid desert will stop being hot and stop being a desert.
You're jumping to the conclusion without paying any attention to whether its existence is plausible.
A humid Middle East will become a tropical land teeming with life like SE Asia. War may happen anyways, but not because additional water made the area uninhabitable.
Maybe you could do a little work and look at the scientific papers published about how they compute the average global temperature.
If it's so well known, you can explain it simply; if you don't know how to explain it, then just say so.
It doesn't matter that much if the global average temperature is not exactly right in the absolute sense.
The derivative of meaningless numbers is also meaningless. That is why the meaning of the original numbers has to be examined and understood, so we can see if the dervative is something to be concerned about.
As long as they use the same methods from one iteration to the next it's a reasonable indication of the trends in temperature which is what we care about most anyway.
They aren't. They extrapolated past temperatures based on ice cores and tree rings, and the current measurement methods are constantly being revised with new technologies.
There's a lot of guess work going on, and it is criminal that measurement error is not reported.
Many of your questions are answered here [nasa.gov], with links provided to further data.
No, they are not answered on that page. Making false statements does not give you credibility.
If you'd like more in-depth information about the exact process [nasa.gov], why not contact an actual climatologist?
I'm asking *you* (or anyone else who's responding) to answer the questions. Show me the layman understandable version, rather than trying to outsource it to some authority figure out there. If you don't know, have the honesty to admit it.
Anything that is understandable can be explained simply. Anyone who claims an issue is too complicated to explain simply does not understand it himself.
Temperatures are measured across the globe and they are all averaged together. Over the past couple of decades, this number has been trending upward, just like measurements of heat-trapping gases in the atmosphere have been trending upward.
What do you think that average means?
Are you averaging night time temperature on one side of the globe to the day time temperature on the other side?
Are you timeshifting the measurement so that you're averaging peaks and lows?
What does that temperature actually mean when it is dependent on humidity, air pressure, time, and environment?
Earth has 200 million square miles of area. What is the coverage of measurements?
I haven't even asked about measurement error.
Maybe put in a little effort to show that you are not trolling?
If you think this is trolling, I have some bad news for you.
As the Nature article today on slashdot points out, even a mild temperature change could possibly do something like turn the entire Middle East extremely humid making it basically uninhabitable. Something this trivial, like a local increase in moisture over a relative small region, could provoke war, even nuclear war.
Why do you think adding moisture to a desert region would make it less habitable?
And doesn't your theory actually make the problem worse (since we have some sort of natural warming plus nobody has explained the mechanism whereby adding greenhouse gases causes zero warming (despite the obvious thermodynamic problems). So according to you that heat must be bunched up somewhere - the obvious conclusion is that (according to your scenario) it will be even warmer in the future than predicted by the consensus science.
Where do you think the heat of "greenhouse warming" comes from?
Slashdot Mirror
The question you have to ask is "Are the number of stations used adequate to derive a global temperature?" Evidence suggests it is. In particular I'd like to point out the Berkeley Earth project. They use all available data including over 39,000 unique stations yet their results aren't significantly different than NOAA, NASA and HADCRUT. So I have a hard time dinging NOAA for using a limited number of stations as long as it's statistically justified.
The question I'm asking is if "global" temperature is the right thing to measure?
Can you convert that global temperature into a measure of the earth's heat energy, as a measure of the net energy the earth has retained from sunlight? No.
When heat and radiation energy can be stored as chemical energy and vice versa, there's a lot that we're not measuring that are important factors.
The tools are inadequate to detect a problem.
"My" theory?
Correct.
I have not offered a theory. You lack reading comprehension.
Excellent. If you are correct, and greenhouse gases have no warming effect then this is obviously something you have proven experimentally. Cite the relevant paper in which you published your results.
This is a false dilemma. Pointing out that "greenhouse gases cause warming" has insufficient evidence does not require me to take another position.
I do not need to offer the right answer to say that 1+1 = 3 is wrong.
Cite the relevant paper which demonstrates the dependency on the "earths temperature" to prove/disprove the greenhouse gas effect.
Cite the relevant paper that demonstrates that we need to isolate the effect of CO2 to prove/disprove the greenhouse gas effect.
I don't need to cite anything. I am pointing out your logical fallacy. You don't even know how to know truth.
The temperature of the surface of the Earth is well-defined
No it is not. Have you gone outside lately? Walked in the sun, rested in the shade, sat on the grass? Coming up with a single temperature number for 200 million square miles and a corresponding volume is not well defined or even meaningful.
The first thing you need to know about any model is that it's definitely wrong.
The second thing you need to know is that with the right assumptions, you can make the model usefully wrong.
And that's what I'm doing - checking if anyone here actually knows what the assumptions are, and how or why they are right.
When you make a wrong statement like the quoted one above, that's an indication that you don't have the right assumptions, and so your model is uselessly wrong.
Your problem is that you're asking highly technical questions with no short answers on Slashdot, rather than digging into the scientific literature.
"What's a `global temperature'?" is not a highly technical question.
Based on the responses so far, it doesn't actually have any meaning, which makes being concerned about its derivative pointless.
theoretically anyone can do it, but in practice it requires certain skills and a lot of work.
I'm an engineer. I analyze complex systems. The earth is a complex system, and I can understand the techniques being used here enough to know they are inadequate for the stated purpose.
I see; you're after an argument, not information. Have fun with that!
I was looking for information. The information I got is that irrelevant links are treated as useful answers.
That's information about the reading comprehension and technical background of the responders.
It's more about the balance between incoming solar radiation and outgoing radiation.
So net energy the earth receives from the sun?
This is why I want this explanation. It shouldn't be this hard to find out what we think we're measuring with "global average surface temperature".
No one is collecting global average temperature today. It's a derived number by taking the temperatures from hundreds of separate weather stations. While the coverage was less in the 1880's it was still adequate to derive a global average temperature, just with slightly higher error ranges than current ones.
These are important details for any discussion on this issue, buried in the fine print.
Google says Earth has roughly 200 million square miles of surface area. With hundred of measuring stations, that means each station is responsible for sampling several hundred thousand square miles.
The original question was, "What is global temperature?"
The answer, according to these facts, is an indirect measure of the energy the earth keeps from the sun, using an average extrapolated from hundreds of temperature measurements from the earth's surface, with each sample representing several hundred thousand square miles.
I thank you for actually trying to answer the question; most of the other responses failed at increasing understanding.
It appears that you are confused about the nature of the greenhouse effect (confusing it with greenhouses or some blather about "chemical reactions") which doesn't bode well for proving your theory that increasing the concentration of greenhouse gases leads to zero warming.
"My" theory? Reading comprehension is not your strong suite. I am criticizing your critique of someone else's position.
You inserted your own assumption that so called greenhouse gases must cause some warming effect into his position and treated that as an internal contradiction.
That's nonsense, because it's your assumption. The point about greenhouses is merely that the common words used in this debate are abused beyond their meaning.
Are you able to prove your theory that increasing the concentration of greenhouse gases leads to zero warming? Yes or No?
The ability to measure "earth's temperature" has insufficient precision or accuracy to prove or disprove "zero warming". Never mind that the earth is too complex a system to isolate the effect of CO2.
The Middle east is already extremely hot, and at the edge of human endurance. If, with no other changes, it also had added moisture, the humidity level would rise dramatically. assuming this was stable (and it didn't get driven off by existing patterns), this would raise the total heat index considerably, potentially beyond human inhabitability.
You've never lived in a desert, I take it?
Do you know what a swamp cooler is?
Sure it makes sense. We have additional CO2 in the air, warming the atmosphere. We know this happens. The planet is retaining more heat because of it. Therefore, if the recent temperature rise has nothing to do with CO2, then the additional heat from the CO2 has to be somewhere on the planet, and when that repository gets full we're going to have even more temperature rise.
Circular reasoning. We assume that CO2 raises temperature, so if we don't observe CO2 raising temperature, then CO2 must be raising the temperature somewhere else, even if we fail to observe it.
Transforming your assumptions into dogma is a horrible way to practice science.
Greenhouses don't trap heat using chemical reactions, or anything related to "Arrhenius".
Why are you telling me to look up irrelevant topics to answer straightforward questions?
The simplest explanation is that you don't know the answer.
Just because measurements aren't accurate doesn't mean they're meaningless.
That is not related to my question. A number is assigned to Earth and the number is shown to change over time. That number doesn't carry it's own meaning. It's the unit that gives it meaning. Now, if there unit were of mass, that'd be straight forward - what's the total mass of earth? If it were of velocity, that's also straight forward enough - where is this big ball of mass going in space and time?
But "global temperature"? That's not straightforward at all. Temperature is volatile and dependent on many factors. Same heat content put into different substances gives you different temperature readings.
Let's say we measured every human's internal temperature and created a global average human temperature- what meaning does that have for earth's global temperature? Not much - humans are warm blooded mammals that regulate their internal temperature, and are only a tiny percentage of the earth's total volume or mass. What you choose to measure changes the meaning of the final number.
If we're consistently measuring the Earth at 0.5C low, then we know what the temperature changes are.
And the number is nonsensical if not properly understood. The temperature swing from morning to night is several magnitudes greater than 0.5C. The temperature swing from season to season is several magnitudes greater than 0.5C.
There is so much innate volatility in a temperature number that the definition of "average" adds a very large number of assumptions that need to be qualified.
Measurement error does seem to be reported. For example, 2014 is the hottest year measured in human times, but the information came with the caveat that the measurement errors are such that it might well not be.
Reported is not the same as verified. When it comes to science, your margin of error matters more than your actual results.
Every unqualified assumption adds error to the results. That's why I'm asking these questions, and the lack of good answers indicates a very, very large margin of error in what is said to be known.
This is prejudice masquerading as science, and people who actually like science should be concerned about this.
I didn't say it was simple. It involved gridded area weighted averages over the whole surface of the Earth.
I didn't say it was simple either. But even complex systems can be described simply. For example, you could say that the global average temperature reflects the net amount of heat the earth traps from the sun.
Is that what it means?
The global average temperatures since 1880 have nothing to do with ice cores, tree rings or other proxies. They're based on thermometer measurements only.
No one was collecting "global average temperature" in 1880. Didn't have the tools or coverage.
What you actually have is "projected global average temperature based on the 1880 temperature measurements we happen to have".
Those 1880 temperature measurements are not made with the same tools or methods as our current measurements 130 years later. We have a lot more research money going into the topic right now. Some of that money ends up in sophisticated new temperature measuring tools which did not exist 130 years ago.
Oh wait. No, that doesn't happen. A humid middle east would take thousands of years to become like SE Asia.
Just like it took thousands of years to transform California into prime agricultural farmland, amirite?
I didn't say deserts are always hot, so you need to work on your own reading comprehension.
Don't project your lack of understanding on me.
So you have no interest in learning, you just want to ask questions and ignore the answers, hoping that you don't have to think about this any more. Your ignorance, and your acceptance of it, is astounding.
Asking *you* to explain it to me is the opposite of accepting ignorance.
The inability of various responders to provide answers is the actual ignorance.
How hard is it to give a simple answer and then point to an authoritative source? But the simple answer is skipped and the responders hide behind the supposed authority.
Do you think greenhouse warming is a function of chemical reaction rates?
It's a simple fact that humans can't survive if the wet bulb temperature is 35C (95F) or greater. If the combination of temperature and humidity reaches that state it's impossible for your body to cool by sweating.
Keyword: "If". None of that is relevant.
Deserts have hot temperatures because they lack water to absorb the heat. A humid desert will stop being hot and stop being a desert.
You're jumping to the conclusion without paying any attention to whether its existence is plausible.
A humid Middle East will become a tropical land teeming with life like SE Asia. War may happen anyways, but not because additional water made the area uninhabitable.
Maybe you could do a little work and look at the scientific papers published about how they compute the average global temperature.
If it's so well known, you can explain it simply; if you don't know how to explain it, then just say so.
It doesn't matter that much if the global average temperature is not exactly right in the absolute sense.
The derivative of meaningless numbers is also meaningless. That is why the meaning of the original numbers has to be examined and understood, so we can see if the dervative is something to be concerned about.
As long as they use the same methods from one iteration to the next it's a reasonable indication of the trends in temperature which is what we care about most anyway.
They aren't. They extrapolated past temperatures based on ice cores and tree rings, and the current measurement methods are constantly being revised with new technologies.
There's a lot of guess work going on, and it is criminal that measurement error is not reported.
Many of your questions are answered here [nasa.gov], with links provided to further data.
No, they are not answered on that page. Making false statements does not give you credibility.
If you'd like more in-depth information about the exact process [nasa.gov], why not contact an actual climatologist?
I'm asking *you* (or anyone else who's responding) to answer the questions. Show me the layman understandable version, rather than trying to outsource it to some authority figure out there. If you don't know, have the honesty to admit it.
Anything that is understandable can be explained simply. Anyone who claims an issue is too complicated to explain simply does not understand it himself.
Temperatures are measured across the globe and they are all averaged together. Over the past couple of decades, this number has been trending upward, just like measurements of heat-trapping gases in the atmosphere have been trending upward.
What do you think that average means?
Are you averaging night time temperature on one side of the globe to the day time temperature on the other side?
Are you timeshifting the measurement so that you're averaging peaks and lows?
What does that temperature actually mean when it is dependent on humidity, air pressure, time, and environment?
Earth has 200 million square miles of area. What is the coverage of measurements?
I haven't even asked about measurement error.
Maybe put in a little effort to show that you are not trolling?
If you think this is trolling, I have some bad news for you.
You have linked a study that uses computer models to create scary looking maps with lots of red.
Do you know what specific heat is, and what water is notable for with regards to that attribute?
When the heat is coming from the sun, does it make sense that " heat must be bunched up somewhere" per the post I was responding to?
Yes, there are multiple methods. But if you don't know what you are measuring, your upward trend is meaningless.
Again, what is the meaning of "global average surface temperature"?
It doesn't matter, on average. Let's say we know thermometers are off +/- 1 degrees.
No, we don't know that the thermometer measurements have an equal distribution of bias around 0.
Tools and procedures all contribute error, and until the error is measured and controlled, measurement error exceeds what you think you know.
As the Nature article today on slashdot points out, even a mild temperature change could possibly do something like turn the entire Middle East extremely humid making it basically uninhabitable. Something this trivial, like a local increase in moisture over a relative small region, could provoke war, even nuclear war.
Why do you think adding moisture to a desert region would make it less habitable?
And doesn't your theory actually make the problem worse (since we have some sort of natural warming plus nobody has explained the mechanism whereby adding greenhouse gases causes zero warming (despite the obvious thermodynamic problems). So according to you that heat must be bunched up somewhere - the obvious conclusion is that (according to your scenario) it will be even warmer in the future than predicted by the consensus science.
Where do you think the heat of "greenhouse warming" comes from?