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So here's an honest question from an honest climate skeptic: how come every time we update our understanding of climate, invariably it turns out the climate cha

So here's an honest question from an honest climate skeptic: how come every time we update our understanding of climate, invariably it turns out the climate change is worse than we thought before? I understand that science is never perfect, so with each discovery we re-evaluate our estimations about climate change, but it should be roughly 50-50. I understand a bit of bias in reporting, so I would expect to see 60-40 or 70-30, but how come it's close to 99-01? I will not pretend that I don't have my own explanations (such as big conflict of interest of climate scientists, who would see their career advance if their findings confirm the doom and gloom consensus), but would someone care to change my mind? (preferably without ad-hominem attacks).

munk-a 8y ago
A lot of recent updates showing more severe consequences for not addressing global warming are due to prior models making optimistic assumptions that we keep needing to strip away, and there is a lot of guess work here... Macro-climate science isn't the sort of thing you can experiment on and the historical data isn't very easy to discern and doesn't include a lot of the modern day factors.
petermcneeley 8y ago
Here is one example of what your looking for https://e360.yale.edu/features/air-pollutions-upside-a-brake-on-global-warming https://e360.yale.edu/features/air-pollutions-upside-a-brake...
- credit_guy 8y ago
  Fair enough. This one I never saw, but I remember seeing one other article saying we now think there are more trees than we estimated before. But for every article like this there are easily 100 saying that whatever new thing we discovered points to a faster pace of global warming. Is my impression wrong?
DougWebb 8y ago
I would guess that scientists are conservative in their predictions, so that they don't over-estimate effects. As new information comes in and predictions become more accurate, it's more likely to lean towards worse outcomes because the earlier predictions were already biased the other way.
- credit_guy 8y ago
  Look, that's a possible explanation. But are you sure you are not rationalizing? They would need to quite a bit conservative so that pretty much any new update would be towards faster warming. Here's the 2007 IPCC estimate: "For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios". [1] Now, it did appear that estimate was slightly conservative. The actual warming for the first decade according to NASA [2] was about 0.27°C. [1]https://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html https://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm... [2]https://climate.nasa.gov/vital-signs/global-temperature/ https://climate.nasa.gov/vital-signs/global-temperature/
  - MikeHolman 8y ago
    From what you say, they underestimated by 35%. That seems like quite a conservative underestimate.
    - credit_guy 8y ago
      Well, my first link follows with this quote: "Since IPCC’s first report in 1990, assessed projections have suggested global average temperature increases between about 0.15°C and 0.3°C per decade for 1990 to 2005. This can now be compared with observed values of about 0.2°C per decade, strengthening confidence in near-term projections." But guess what. My second link, the NASA one, shows the global increase of temperature between 2001 and 2011 to be 0.03°C. The IPCC estimate was not that conservative, was it? Should I say it was aggressive by a factor of 6? Nope, I'm not saying that. What I'm saying (and what IPCC is saying) is that generally their predictions appear to be in line with the outcome, and not to be very conservative.
mamcx 8y ago
> but it should be roughly 50-50 Nope. That is law that don't exist. In fact, do you remember "not bad thing come alone?". Things always can go wrong faster, and when things go wrong, them multiply and accelerate. Think, for example, what happend if you lost your job. Then you get behind old debts. Then you get a lot of stress in family,. Then you think "lets drink a little / smoke pot" then you continue doing that.... When certains things go wrong, them multiply, amplify and create side-effects. Or in other words, is like a computer crash. When the process get corrupted and you continue along without stop and diagnose properly...
davewasthere 8y ago
For one thing, take the tabloid headlines with a grain of salt. This article should actually read something like "Interesting new way to measure warming oceans could be even more accurate". But in reality, they still model/interpolate the results between the many thousands of measuring points, which is still just part of the picture. Which hasn't really changed that much, just a gradual refining. Which is sort of how science works. By the way, as a skeptic, you have access to the raw data yourself and can come up with a hypothesis that the oceans aren't warming and prove it yourself. http://www.argodatamgt.org/Access-to-data http://www.argodatamgt.org/Access-to-data I don't think climate change is worse than we thought. It's more that it's becoming acceptable to report it in those terms and gradually that's how the populace as a whole are coming to view it. The key thing appears to be political will. You get the full spectrum of politicians. Some have been pushing for environmental policies since the 60's and 70's when it was very fringe (and scientists were already giving us plenty of warning - with claims of CO2 causing radical climate effects if unchecked... as it mostly has been). Then you've got the muppets who are still in denial and don't appear to give a shit about what sort of planet is left to the next generation(s).
- credit_guy 8y ago
  Thanks for the thoughtful reply. I think it's very likely you are right. Also thanks for the link to the data. I tried in the past to get access to actual raw data so I can play with it, and draw my own conclusions, but all I got was always many levels above the raw data. Your point about politicians in denial is 100% on. And as a skeptical guy it bothers me that people perceive me as being somehow in the same boat as them. It is my perception that those guys are not really trying to find truth, or what's best for humankind, or anything beyond what will get them elected in the next cycle. However, that being said, I'm still skeptical. To give you an example, how many times did you not read in the media that Greenland is melting. Well, here's the real time data about the Greenland ice sheet mass [1]. Have you ever heard that the mass accumulation for the 2017-18 year was way above the 30-year mean? Edit: Also, thanks the Hacker News community. This is the first time I express my views on climate change without using a throwaway account, and I fully expected my karma to take a huge hit. So far it didn't, it stayed about flat. I expected to be destroyed in the comments. Nope, all comments have been respectful. Well done Hacker News. [1] https://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/ https://www.dmi.dk/en/groenland/maalinger/greenland-ice-shee...
danharaj 8y ago
> but it should be roughly 50-50. Why do you think that?
colordrops 8y ago
I saw an interview with climate scientists and they discussed this issue. They said that the numbers they report to government agencies and other authoritative organizations are typically the more conservative end of margins in their studies due to political pressure.
empath75 8y ago
> who would see their career advance if their findings confirm the doom and gloom consensus There's a lot more money to be made by saying there's no global warming.
- whatshisface 8y ago
  How can an unscrupulous scientist sign up? Nobody has offered me any money...
  - empath75 8y ago
    Go work for a think tank funded by the Koch’s
  - awinder 8y ago
    Go into business for yourself with enough vitriol to gain the attention of the bannons, malkins, and coulters of the world? Join a company like shell, which has been doing “the climate science” for decades? Idk, we live in a great time for unscrupulous people, I’m sure you could find the opportunities if you tried.
  - yongjik 8y ago
    First you have to be famous, because any village idiot can say "LOL climate science is bunk". Like C-level executives, it's hard to get into the game. But I guess it's pretty lucrative once you get in.
stouset 8y ago
First, in what way are you skeptical? That the planet is warming? That humans have anything to do with it? That it’s a result of greenhouse gas emissions? That its effects will be catastrophic? Others have addressed your direct question in more detail: the predictions keep getting worse because a) the original predictions were conservative (“there’s no way it can get that bad”, “there’s no way we won’t begin to react”, etc.), b) we’re getting more data from recent years as the planet does begin to warm and seeing that it’s happening faster than many models predicted so new models have to incorporate this new worrying information, and c) there’s often biases in reporting on top of these other things.
crooked-v 8y ago
Consider the ever-accelerating pace of industrialization in previously third-world countries. China currently has twice the carbon emissions of the US, and very little of that existed when climate change estimations started in the 60s.
mannykannot 8y ago
If you want to avoid ad-hominem attacks, maybe you shouldn't present an unsubstantiated speculation about the motivations of climate scientists as your only hypothesis for 'explaining' what turns out to be (as others have pointed out) a faulty intuition? Here's another motivation-based argument to think about: the organized, often irrational and sometimes threatening campaign of denial might have induced a tendency to discuss only the most bulletproof predictions, resulting in lowball estimates that will most likely rise as more evidence is uncovered.
- ravenstine 8y ago
  > If you want to avoid ad-hominem attacks, maybe you shouldn't present an unsubstantiated speculation about the motivations of climate scientists as your only hypothesis for 'explaining' what turns out to be (as others have pointed out) a faulty intuition? Why would that warrant an ad hominem attack?
  - mannykannot 8y ago
    It doesn't warrant an ad hominem attack, it's pointing out an inconsistency - the claim about climate scientists' motives is as ad-hominem as many examples to be found in dictionaries. To his credit, credit_guy has been willing to consider alternative explanations than the one he started with.
tasty_freeze 8y ago
The international climate reports (IPCC) are the result of a lot of scientific work followed by heavy politicking. When early reports from the scientists were alarming, the reports were watered down instead of stating the 50% case. Some of the politics came from the committee being afraid of overstating things, but perhaps a larger amount came from the US contingent basically saying they wouldn't endorse the report unless it got watered down. What is why, as time went on, more data was collected, and the science got more confident, the results get revised upwards. The first google hit after searching on "IPCC political pressure" https://www.theguardian.com/environment/earth-insight/2014/may/15/ipcc-un-climate-reports-diluted-protect-fossil-fuel-interests https://www.theguardian.com/environment/earth-insight/2014/m... Though that report is from 2014, it has been going for 20 years.
nostrademons 8y ago
Could be that climate exhibits a lot of positive-feedback effects, more-so than most of the early models predicted. If you start by modeling climate as a linear relationship between atmospheric CO2 and temperature and then it turns out that it's that plus human CO2 production is accelerating as the developing world develops plus release of trapped CO2 in the permafrost plus decreased albedo as the glaciers melt plus the albedo effect from increased vegetation plus reduction of the moderating effect of ocean currents as they're disrupted by incoming meltwater, then you're going to continually find that your models were too conservative. I don't buy a lot of the climate hysteria either, but for entirely different (and more depressing) reasons. I think that the reality is significantly worse than the scientists are portraying, but this doesn't matter much because we're still talking 2-4C over a century, and a century is a very long time in human progress. A century ago the world population was less than 2B, barely anyone had cars, North America and Europe were the only developed regions, coal was the predominant energy source, and hot cities like Las Vegas, Houston, and Phoenix were extremely undesirable places to live because of the lack of air conditioning. The media portrays the eventual flooding of NYC due to sea-level rise as an apocalyptic tragedy, but the fact is that several other cities (Galveston TX, New Orleans LA, Sacramento CA) have lost their pre-eminent economic position as a result of floods, and many others (Salem MA, Baltimore MD, Detroit MI and the rest of the rust belt) have from economic changes. Society adapts; people migrate and move from dying cities to new up-and-comers on more solid ground. A century is 3-4 generations, plenty of time for this migration to happen in terms of younger generations picking where they want to put down roots. I think we're far more likely to go out in a blaze of war from the social strain that come from this large-scale migration. Humans don't do well with relative changes in social status or power levels. They tend to want to find somebody else to blame and fight. I'd give better-than-even odds that the climate is actually cooler at the end of this century than now, but only because we've triggered nuclear war and are in the midst of a nuclear winter.
hsavit1 8y ago
You've been rejecting climate change evidence for years - your mind is clearly already made up. Nobody on this comment board is going to be able to convince you of how to reasonably react to overwhelming evidence. "Convincing" will happen when you can accept reality for what it is, instead of rejecting it for your own sadistic individualistic pleasure.
mikeash 8y ago
Feynman describes a likely reason: “We have learned a lot from experience about how to handle some of the ways we fool ourselves. One example: Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It's a little bit off because he had the incorrect value for the viscosity of air. It's interesting to look at the history of measurements of the charge of an electron, after Millikan. If you plot them as a function of time, you find that one is a little bit bigger than Millikan's, and the next one's a little bit bigger than that, and the next one's a little bit bigger than that, until finally they settle down to a number which is higher. “Why didn't they discover the new number was higher right away? It's a thing that scientists are ashamed of—this history—because it's apparent that people did things like this: When they got a number that was too high above Millikan's, they thought something must be wrong—and they would look for and find a reason why something might be wrong. When they got a number close to Millikan's value they didn't look so hard. And so they eliminated the numbers that were too far off, and did other things like that....”

munk-a 8y ago

A lot of recent updates showing more severe consequences for not addressing global warming are due to prior models making optimistic assumptions that we keep needing to strip away, and there is a lot of guess work here... Macro-climate science isn't the sort of thing you can experiment on and the historical data isn't very easy to discern and doesn't include a lot of the modern day factors.

petermcneeley 8y ago

Here is one example of what your looking for https://e360.yale.edu/features/air-pollutions-upside-a-brake-on-global-warming https://e360.yale.edu/features/air-pollutions-upside-a-brake...

credit_guy 8y ago
Fair enough. This one I never saw, but I remember seeing one other article saying we now think there are more trees than we estimated before. But for every article like this there are easily 100 saying that whatever new thing we discovered points to a faster pace of global warming. Is my impression wrong?

DougWebb 8y ago

I would guess that scientists are conservative in their predictions, so that they don't over-estimate effects. As new information comes in and predictions become more accurate, it's more likely to lean towards worse outcomes because the earlier predictions were already biased the other way.

credit_guy 8y ago
Look, that's a possible explanation. But are you sure you are not rationalizing? They would need to quite a bit conservative so that pretty much any new update would be towards faster warming. Here's the 2007 IPCC estimate: "For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios". [1] Now, it did appear that estimate was slightly conservative. The actual warming for the first decade according to NASA [2] was about 0.27°C. [1]https://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html https://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm... [2]https://climate.nasa.gov/vital-signs/global-temperature/ https://climate.nasa.gov/vital-signs/global-temperature/
- MikeHolman 8y ago
  From what you say, they underestimated by 35%. That seems like quite a conservative underestimate.
  - credit_guy 8y ago
    Well, my first link follows with this quote: "Since IPCC’s first report in 1990, assessed projections have suggested global average temperature increases between about 0.15°C and 0.3°C per decade for 1990 to 2005. This can now be compared with observed values of about 0.2°C per decade, strengthening confidence in near-term projections." But guess what. My second link, the NASA one, shows the global increase of temperature between 2001 and 2011 to be 0.03°C. The IPCC estimate was not that conservative, was it? Should I say it was aggressive by a factor of 6? Nope, I'm not saying that. What I'm saying (and what IPCC is saying) is that generally their predictions appear to be in line with the outcome, and not to be very conservative.

mamcx 8y ago

> but it should be roughly 50-50 Nope. That is law that don't exist. In fact, do you remember "not bad thing come alone?". Things always can go wrong faster, and when things go wrong, them multiply and accelerate. Think, for example, what happend if you lost your job. Then you get behind old debts. Then you get a lot of stress in family,. Then you think "lets drink a little / smoke pot" then you continue doing that.... When certains things go wrong, them multiply, amplify and create side-effects. Or in other words, is like a computer crash. When the process get corrupted and you continue along without stop and diagnose properly...

davewasthere 8y ago

For one thing, take the tabloid headlines with a grain of salt. This article should actually read something like "Interesting new way to measure warming oceans could be even more accurate". But in reality, they still model/interpolate the results between the many thousands of measuring points, which is still just part of the picture. Which hasn't really changed that much, just a gradual refining. Which is sort of how science works. By the way, as a skeptic, you have access to the raw data yourself and can come up with a hypothesis that the oceans aren't warming and prove it yourself. http://www.argodatamgt.org/Access-to-data http://www.argodatamgt.org/Access-to-data I don't think climate change is worse than we thought. It's more that it's becoming acceptable to report it in those terms and gradually that's how the populace as a whole are coming to view it. The key thing appears to be political will. You get the full spectrum of politicians. Some have been pushing for environmental policies since the 60's and 70's when it was very fringe (and scientists were already giving us plenty of warning - with claims of CO2 causing radical climate effects if unchecked... as it mostly has been). Then you've got the muppets who are still in denial and don't appear to give a shit about what sort of planet is left to the next generation(s).

credit_guy 8y ago
Thanks for the thoughtful reply. I think it's very likely you are right. Also thanks for the link to the data. I tried in the past to get access to actual raw data so I can play with it, and draw my own conclusions, but all I got was always many levels above the raw data. Your point about politicians in denial is 100% on. And as a skeptical guy it bothers me that people perceive me as being somehow in the same boat as them. It is my perception that those guys are not really trying to find truth, or what's best for humankind, or anything beyond what will get them elected in the next cycle. However, that being said, I'm still skeptical. To give you an example, how many times did you not read in the media that Greenland is melting. Well, here's the real time data about the Greenland ice sheet mass [1]. Have you ever heard that the mass accumulation for the 2017-18 year was way above the 30-year mean? Edit: Also, thanks the Hacker News community. This is the first time I express my views on climate change without using a throwaway account, and I fully expected my karma to take a huge hit. So far it didn't, it stayed about flat. I expected to be destroyed in the comments. Nope, all comments have been respectful. Well done Hacker News. [1] https://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/ https://www.dmi.dk/en/groenland/maalinger/greenland-ice-shee...

danharaj 8y ago

> but it should be roughly 50-50. Why do you think that?

colordrops 8y ago

I saw an interview with climate scientists and they discussed this issue. They said that the numbers they report to government agencies and other authoritative organizations are typically the more conservative end of margins in their studies due to political pressure.

empath75 8y ago

> who would see their career advance if their findings confirm the doom and gloom consensus There's a lot more money to be made by saying there's no global warming.

whatshisface 8y ago
How can an unscrupulous scientist sign up? Nobody has offered me any money...
- empath75 8y ago
  Go work for a think tank funded by the Koch’s
- awinder 8y ago
  Go into business for yourself with enough vitriol to gain the attention of the bannons, malkins, and coulters of the world? Join a company like shell, which has been doing “the climate science” for decades? Idk, we live in a great time for unscrupulous people, I’m sure you could find the opportunities if you tried.
- yongjik 8y ago
  First you have to be famous, because any village idiot can say "LOL climate science is bunk". Like C-level executives, it's hard to get into the game. But I guess it's pretty lucrative once you get in.

stouset 8y ago

First, in what way are you skeptical? That the planet is warming? That humans have anything to do with it? That it’s a result of greenhouse gas emissions? That its effects will be catastrophic? Others have addressed your direct question in more detail: the predictions keep getting worse because a) the original predictions were conservative (“there’s no way it can get that bad”, “there’s no way we won’t begin to react”, etc.), b) we’re getting more data from recent years as the planet does begin to warm and seeing that it’s happening faster than many models predicted so new models have to incorporate this new worrying information, and c) there’s often biases in reporting on top of these other things.

crooked-v 8y ago

Consider the ever-accelerating pace of industrialization in previously third-world countries. China currently has twice the carbon emissions of the US, and very little of that existed when climate change estimations started in the 60s.

mannykannot 8y ago

If you want to avoid ad-hominem attacks, maybe you shouldn't present an unsubstantiated speculation about the motivations of climate scientists as your only hypothesis for 'explaining' what turns out to be (as others have pointed out) a faulty intuition? Here's another motivation-based argument to think about: the organized, often irrational and sometimes threatening campaign of denial might have induced a tendency to discuss only the most bulletproof predictions, resulting in lowball estimates that will most likely rise as more evidence is uncovered.

ravenstine 8y ago
> If you want to avoid ad-hominem attacks, maybe you shouldn't present an unsubstantiated speculation about the motivations of climate scientists as your only hypothesis for 'explaining' what turns out to be (as others have pointed out) a faulty intuition? Why would that warrant an ad hominem attack?
- mannykannot 8y ago
  It doesn't warrant an ad hominem attack, it's pointing out an inconsistency - the claim about climate scientists' motives is as ad-hominem as many examples to be found in dictionaries. To his credit, credit_guy has been willing to consider alternative explanations than the one he started with.

tasty_freeze 8y ago

The international climate reports (IPCC) are the result of a lot of scientific work followed by heavy politicking. When early reports from the scientists were alarming, the reports were watered down instead of stating the 50% case. Some of the politics came from the committee being afraid of overstating things, but perhaps a larger amount came from the US contingent basically saying they wouldn't endorse the report unless it got watered down. What is why, as time went on, more data was collected, and the science got more confident, the results get revised upwards. The first google hit after searching on "IPCC political pressure" https://www.theguardian.com/environment/earth-insight/2014/may/15/ipcc-un-climate-reports-diluted-protect-fossil-fuel-interests https://www.theguardian.com/environment/earth-insight/2014/m... Though that report is from 2014, it has been going for 20 years.

nostrademons 8y ago

Could be that climate exhibits a lot of positive-feedback effects, more-so than most of the early models predicted. If you start by modeling climate as a linear relationship between atmospheric CO2 and temperature and then it turns out that it's that plus human CO2 production is accelerating as the developing world develops plus release of trapped CO2 in the permafrost plus decreased albedo as the glaciers melt plus the albedo effect from increased vegetation plus reduction of the moderating effect of ocean currents as they're disrupted by incoming meltwater, then you're going to continually find that your models were too conservative. I don't buy a lot of the climate hysteria either, but for entirely different (and more depressing) reasons. I think that the reality is significantly worse than the scientists are portraying, but this doesn't matter much because we're still talking 2-4C over a century, and a century is a very long time in human progress. A century ago the world population was less than 2B, barely anyone had cars, North America and Europe were the only developed regions, coal was the predominant energy source, and hot cities like Las Vegas, Houston, and Phoenix were extremely undesirable places to live because of the lack of air conditioning. The media portrays the eventual flooding of NYC due to sea-level rise as an apocalyptic tragedy, but the fact is that several other cities (Galveston TX, New Orleans LA, Sacramento CA) have lost their pre-eminent economic position as a result of floods, and many others (Salem MA, Baltimore MD, Detroit MI and the rest of the rust belt) have from economic changes. Society adapts; people migrate and move from dying cities to new up-and-comers on more solid ground. A century is 3-4 generations, plenty of time for this migration to happen in terms of younger generations picking where they want to put down roots. I think we're far more likely to go out in a blaze of war from the social strain that come from this large-scale migration. Humans don't do well with relative changes in social status or power levels. They tend to want to find somebody else to blame and fight. I'd give better-than-even odds that the climate is actually cooler at the end of this century than now, but only because we've triggered nuclear war and are in the midst of a nuclear winter.

hsavit1 8y ago

You've been rejecting climate change evidence for years - your mind is clearly already made up. Nobody on this comment board is going to be able to convince you of how to reasonably react to overwhelming evidence. "Convincing" will happen when you can accept reality for what it is, instead of rejecting it for your own sadistic individualistic pleasure.

mikeash 8y ago

Feynman describes a likely reason: “We have learned a lot from experience about how to handle some of the ways we fool ourselves. One example: Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It's a little bit off because he had the incorrect value for the viscosity of air. It's interesting to look at the history of measurements of the charge of an electron, after Millikan. If you plot them as a function of time, you find that one is a little bit bigger than Millikan's, and the next one's a little bit bigger than that, and the next one's a little bit bigger than that, until finally they settle down to a number which is higher. “Why didn't they discover the new number was higher right away? It's a thing that scientists are ashamed of—this history—because it's apparent that people did things like this: When they got a number that was too high above Millikan's, they thought something must be wrong—and they would look for and find a reason why something might be wrong. When they got a number close to Millikan's value they didn't look so hard. And so they eliminated the numbers that were too far off, and did other things like that....”