Level of oxygen for example can be estimated from layers of ice. Mann used tree slice(s) for temperature estimation.
There's a lot of problems with proxy data and their models and there is a lot of space for scientific misdemeanor. Some journals recently started to require a full disclosure of all data and models on which they base their claims, which - surprisingly - isn't always the case.
As more data is gathered over time some models need to be adjusted. How much they need to be adjusted reflects quality of the model.
It's a seriously sad state of affairs, but nothing new really, if you think about it. The reach of modern communications has inflated the problem in my opinion.
[1] - http://simplikation.com/why-sealioning-is-bad/
1) You can't tell whether someone is "just asking questions" in good faith or not.
2) Dismissing a horde of people all raising the same problems with one's beliefs as "sealions" is a tempting shortcut to actually examining one's beliefs, which might in fact be wrong.
You are not a priest preaching to the ignorant congregation, if you don't want to deal with the bullshit get off the fucking podium.
I do not generally get involved in the climate change debate because it has multiple problems: it happens on scales (both time and space) that humans have difficulty observing, it is about a system with lots of feedback that could very well behave chaotically, direct observations of the phenomenon are limited compared to its timescale, experts of the subject are operating under perverse incentives, it is highly politicized and almost everything that's easy to read about the subject is blatant propaganda (see all the climate change denialist posted in this thread as well as the OP).
Your question is hard to answer because it assumes there is a shared and agreed upon definition of the word "science" that can be used to determine with certainty wethere something is science or not.
> Is it like a social science? I think someone told me that we know for sure that greenhouse gas emissions cause ozone depletion but I can't remember anymore. What is the actual hard science here?
I think it is in better shape than the average social science, the greenhouse effect and the ozone depletion are two separate phenomena, this [1] is the experiment that explains how the greenhouse effect works, the wikipedia page about ozone depletion explains the chemical reactions that lead to that.
[1] https://en.wikipedia.org/wiki/Svante_Arrhenius#Greenhouse_ef...
My memories of a debate, especially a scientific debate, was that both sides presented their best evidence to determine a likely winner. These days it seems the easiest way to win a debate is to insult the other side enough so that they shut up. If someone uses that tactic in a debate I immediately question the validity of their viewpoint; because it seems they question it themselves and are not willing to admit it.
Especially when it happens on HN and other sites that I come to to learn and discuss.
To understand these issues and much more, I highly recommend spend a little time on the IPCC reports:
But carbon/methane/NO/etc... they get from ice samples that have trapped air bubbles from quite a long time ago. They also take a ton of samples from ice cores and the data is reproducible both in the north and south poles. I believe temperature is also learned from the ice samples.
Here is a good example:
https://en.wikipedia.org/wiki/Little_Ice_Age
"Several causes have been proposed: cyclical lows in solar radiation, heightened volcanic activity, changes in the ocean circulation, an inherent variability in global climate, or decreases in the human population."
It seems we don't even know how the little ice age happened. How do we know these same forces aren't changing our environment now?
We've been having all these strange temperatures lately and also this:
http://www.independent.co.uk/life-style/gadgets-and-tech/new...
The problem is that it's too political now. When claimed scientists are coming out and saying the science is "settled", I know we have a problem. Science is never really settled.
It's a great question, one which has occupied many scientists. It has been addressed in detail in the scientific research. See:
https://news.ycombinator.com/item?id=9772353
> The problem is that it's too political now.
Remember that's a well-documented, established technique often used by people who want to obstruct things; create so much noise (as in signal-to-noise) and FUD (Fear, uncertainty, and doubt) as to confuse the public about the facts. In every field, you always can find someone to say anything on TV; heck, you can find tax attorneys who will say you don't have to pay income tax (good luck with that!).
> When claimed scientists are coming out and saying the science is "settled", I know we have a problem. Science is never really settled.
'Settled science' is jargon; it distinguishes theories that are still up in the air (string theory) from theories that have proven themselves as very reliable (gravity). Nothing in the world is ever "settled", but the evidence is pretty certain about climate change:
IIRC, 97% of climate scientists believe it's happening and caused by humans; the US National Academies of Science agree, as does the Royal Society in the UK; the US defense and intelligence communities are planning on it, as is the insurance and other industries. Sure, they all could be wrong, but so could the deniers. Who seems like a better bet, the 3%, or the 97%?
Okay, show me a study that has the details on which parts are human made and which parts are caused by nature (with numbers). I have never seen this anywhere and You would think if they actually knew, we would have seen it by now. This isn't that difficult and it doesn't really make any sense that humans are causing 100%. Especially with things like the little ice age before we were around to pollute the earth.
"the US National Academies of Science agree, as does the Royal Society in the UK; the US defense and intelligence communities are planning on it, as is the insurance and other industries. Sure, they all could be wrong, but so could the deniers. Who seems like a better bet, the 3%, or the 97%?"
Well, if we are going to use this argument, we could very well think the solar system revolves around the earth rather than the sun.
What about our treatment of women and minorities? Everyone did it, so it MUST be the correct behavior..right?
How about smoking? Even Doctors promoted it at the time (they are experts, right?).
Being homosexual and transgender was seen as a mental illness for decades. But all the experts agreed, so it must again be correct, right?
I guess it is a mental illness!! The experts all agreed..I can't go against them..
Even more recently, "Hands up don't shoot". Forensic evidence came out and said that it never happened, yet we have mainstream media and seemingly intelligent people continuing on with the stretching of the truth to fit a narrative.
"but the evidence is pretty certain about climate change"
Yes, the climate is changing (a fact). But we still don't know if it's completely due to man-made changes or nature.
You also left out government funding and the politics around academia, which is very important when it comes to studies. It's pretty well known in the academic world that if you don't support the current narrative, you will not get funding.
I worked for many years in Academia and it's 99% politics if you want to actually get funding. If someone in a higher position doesn't like you for any reason, you can kiss it goodbye.
Climate change (also known as Global warming and Global cooling depending on what the new narrative is for the day) has been talked about since the 1970s. None of the predictions by scientists at that time came even close to true and it was a majority..just like today.
Science shouldn't be about trying to fit the evidence to a narrative. It should be trying to figure out the truth.
If you can't even debate me on these simple questions, how can I ever believe what you are saying is true?
Even the behavior here on HN is pretty telling. I ask a few questions and I am met with: hostility, anger, and people using words like "fucking". If it is this bad here, I can't imagine the climate scientists with contrary evidence. It's just like during the middle ages. Except they won't be burned at the stake, they will lose their careers.
The point is that just because 97% of professionals believe something is true, does not make it so.
https://youtube.com/watch?v=GlcuV_Dojwg
Did you read the IPCC report linked above yet?
How can you trust anything the IPCC or its associated scientists have to say when they have openly advocated deceiving the public?
On top of that, the IPCC has openly encouraged scientists to deceive the public. See, e.g. http://judithcurry.com/2011/07/21/stephen-schneider-and-the-...
So, you have 1) the consensus claim shown to be a lie, and 2) the IPCC shown to be telling scientists to deceive the public.
Either of those facts alone should sink the AGW movement. But it's hard to get the truth out to people who don't care enough to look it up themselves, because the media is invested into the false narrative.
If you had a sore stomach, and asked 2 groups of people to help you figure out why, would you trust the diagnosis from a group with 100 world-class doctors, surgeons, dieticians, etc... or 100 random people? When the random people say "Ya, but the doctor's don't know anything"... why would you believe them?
We've got global consensus from the leading experts in a dozen or so related fields, all pointing to the same thing. I trust the people that landed on the moon and can launch satellites to space to give me better information about the Earth's macro trends than the guy next door that uses his bible and the cold weather last week as his evidence of a trend.
Ironically, many of the same tobacco-cancer link deniers are now working in the service of the global warming denialist bloc. I guess oil barons pay better than southern planters.
Not unless two of those 100 random individuals were Barry Marshall and Robin Warren and the stomach pain was due to a peptic ulcer.
https://en.wikipedia.org/?title=Barry_Marshall
"Marshall and Robin Warren showed that the bacterium Helicobacter pylori (H. pylori) is the cause of most peptic ulcers, reversing decades of medical doctrine holding that ulcers were caused by stress, spicy foods, and too much acid."
The point being that a reasonable belief long held by experts was shown to be false by careful scientific investigation. That said, I don't find this kind of meta-rhetoric helpful as it serves only to steer attention away from the pertinent matter at hand and to shut down discussion.
No, you didn't recall correctly. It's published papers taking a position on AGW and even that number is questionable at best:
To manufacture their misleading asserted consensus, Cook and his colleagues also misclassified various papers as taking “no position” on human-caused global warming. When Cook and his colleagues determined a paper took no position on the issue, they simply pretended, for the purpose of their 97-percent claim, that the paper did not exist.
Morner, a sea level scientist, told Popular Technology that Cook classifying one of his papers as “no position” was “Certainly not correct and certainly misleading. The paper is strongly against AGW [anthropogenic global warming], and documents its absence in the sea level observational facts. Also, it invalidates the mode of sea level handling by the IPCC.”
I guess I didn't realize HN was anti-science and anti-intellectual.
I think you're reading too much into the "the science is settled" comment. It's a field where powerful interests work aggressively to discredit a majority view of scientists, and it's likely that some (magnified by the media) may use a term like that out of frustration to imply consensus and a wish to have policy makers progress on action.
I know it's easy to find an aberration on Wikipedia, but the pros know all that stuff, they live it every minute of the day.