James Hansen on the Warmest Year Brouhaha

Jamie writes "In response to earlier reports, Dr. James Hansen, top climate scientist with NASA, has issued a statement on the recent global warming data correction. He points out 'the effect on global temperature was of order one-thousandth of a degree, so the corrected and uncorrected curves are indistinguishable.' In a second email he shows maps of U.S. temperatures relative to the world in 1934 and 1998, explains why the error occurred (it was not, as reported, a 'Y2K bug') and, in response to errors by 'Fox, Washington Times, and their like,' attacks the 'deceit' of those who 'are not stupid [but] seek to create a brouhaha and muddy the waters in the climate change story.'"

Comments

The bigger issue

[MyLongNickName]

The bigger issue is the cloak of secrecy around the data and the algorithms used to generate the outputs. I do not understand why all data wouldn't be publicly available. Is there one place to go to see the data used to make the dire predictions I hear all over the place? I generally accept global warming as a fact, but when I see the amount of contortions one person had to go through to figure out there was a problem in the first place, I start to get suspicious.

Re:The bigger issue

[Anonymous Coward]

Indeed - in paticular, let's see the algorithm. There could be other bugs. It's just as likely that global warming is WORSE than what is being claimed (imagine if the average temperature is actually 1 degree MORE than what is currently being calculated) as it is (in this case) that there was an error in the denier's favor.

Until the data and the algorithm are available to the public for scrutiny, it's difficult to trust the results, much less make the correct policy decisions (as noted above - if global warming is WORSE than we think, then maybe more drastic action is needed and vice versa).

Re:The bigger issue

[Christianson]

No direct experience with the data in question, or indeed any climatological data at all, but this isn't really an uncommon case in science. People collect and store their own data. The full extent of raw data is often massive, it's often poorly indexed, and there is no such thing as a consistent storage format. Practically speaking, this means that whenever you want to get someone else's data, you have to get in touch with someone who would have collected it, ask them to filter out the part of the data you want, and then send it to you with an explanation of how to make sense of it. It might seem like secrecy, but it's mostly a product of best use of time. Scientists get grant money by analyzing data and publishing the results, not spending the effort to make the raw data publicly available.

Re:The bigger issue

[NickFortune]

Scientists get grant money by analyzing data and publishing the results, not spending the effort to make the raw data publicly available.

mmm... maybe that needs to change. Given the current tendency towards knee jerk FUD in some quarters, the only way we're ever going to be able to settle debates like this one is if the data can be subjected to widespread peer review.

Re:The bigger issue

[Evilest Doer]

Given the current tendency towards knee jerk FUD in some quarters, the only way we're ever going to be able to settle debates like this one is if the data can be subjected to widespread peer review.

I wish I could share your optimism, but widespread peer review won't change anything. The problem is due to people who know nothing or very little (which is often worse than nothing) about the sciences. If the raw data is publicly available, it will give the people who want to deny basic science more ammunition for their inane babblings. They won't in reality know the first thing they are talking about, but it will impress the people who want to believe the world is only 6000 years old, or we never went to the moon, or their is no global warming, and so on.

Re:The bigger issue

[ajs]

they've come to the conclusion with 80% certainty that global climate change is not only real, but is caused by human activities. That's a bit of a mis-statement. The computer models used generate results that conform to that hypothesis with an 80% margin for error. The idea that we're 80% certain that the models are correct is not supported by anything I've read.

As some scientists have pointed out, there's substantial concern about these models and how accurate they can be in the first place. What we know is this: some of the Earth is undergoing substantial climate change (always true, but this is exceptional), and much of the change is in the direction of warming (the arctic and antarctic regions, especially). We also know that CO2 levels have risen. The problem is that correlating those two factors requires that we understand the climate on a macroscopic level, which, sadly, we do not. We have models that predict past activity, but they have so far failed to accurately predict future activity accurately. Dyson suggests a naive model ("no change") would be more accurate that the models we use. That's been hotly debated, and I'm willing to believe that he might have gone a bit overboard there.

Still, the fact of the matter is that we're uncertain about a great many things, and until we are certain, we should be careful about what we insist is "fact".

Re:The bigger issue

[kimvette]

if you re-read my post, I indicated that is not the case, and revealing ALL of the data will convince skeptics if the alarmists are right. Where Mars and other planets are warming there is a good chance that global warming is not due to us, or not largely due to us (I'm convinced we are at least a contributor but not that we are the cause). Having the raw data for mars, as far back as the data goes, can help to show us whether or not we are indeed the cause of global warming, because Mars can be used for control data. Is the temp here rising at the same rate as there? Is the trend here faster? How much faster? Then, we need to investigate why: is it due to plentiful water vapor here, or because of industry-emitted greenhouse gases? Having the full picture helps both sides attain their goals.

My problem is that the alarmists are chicken little, and the right wingers are like the people who listened to the boy who cried wolf so many times. There is a happy medium and that is called the scientific method. Alarmists with an agenda cannot be trusted, and neither can the other extreme with the ostrich syndrome.

Re:The bigger issue

[Glock27]

The bigger issue is the cloak of secrecy around the data and the algorithms used to generate the outputs. I do not understand why all data wouldn't be publicly available. Is there one place to go to see the data used to make the dire predictions I hear all over the place? I generally accept global warming as a fact, but when I see the amount of contortions one person had to go through to figure out there was a problem in the first place, I start to get suspicious.

There are many 'big issues' with the Global Warming (aka Global Climate Change) crowd. Global Warming is still the best term, since the main thesis is clearly increasing global mean temperature. Of course this implies nothing about local climate variation.

First of all, there's the question of whether Global Warming is a real, long-term trend. It's at a minimum interesting that there were reports in the 1920s of widespread arctic ice melting, followed in the 1970s by a "Global Cooling" scare. This recent revision of which was the warmest year in US history casts even more doubt. Looking further back into history, there has been historical warming in Greenland that exceeds the current trend, well before human produced greenhouse gasses could have been a factor.

I think the global warming skeptics are correct in viewing the results of the various computer models with a wary eye. The models are only as good as the data and assumptions fed into them, as well as the actual algorithms used to model absorption, reflection and emission. Further, they are modeling inherently chaotic systems which we have trouble forecasting only a week into the future. Hubris, anyone?

I wonder what the stance of the environmentalists will be if it's scientifically determined that the current climate trends are a natural phenomenon? Surely we shouldn't mess with Mother Nature... ;-)

I personally think the United States, in particular, is doing quite a bit to address greenhouse gas emissions in particular, and pollution in general. If you really want to make a difference, lobby for more nuclear power going forward. What really needs scrutiny now is China (who just passed the US as a CO2 polluter) as well as the other developing nations with little money but a big hunger for energy. So, all you "anti-Western-industrialism" types, you have a new target.

Re:The bigger issue

[yakmans_dad]

There isn't any cloak of secrecy. The data and algorithms are, in fact, all available, contrary to assertions. The corrections to the temp record were done with ad hoc scripts and one-off programs which are sometimes problematic to track down and replicate. (c.f. any sufficiently busy academic's desk). If one has a doubt about the accuracy, code it yourself and, if the results vary from the published ones, publish a note which describes the differences. That's countering science with science, not science with quibble. Calibration time. The famous anti "hockey stick" paper was bolstered by a graph which changed the scale of the y-axis by almost an order of magnitude. The "hockey sticks" produced would have shown up in the original graph as so much flutter. Which global warming skeptic publicly objected to that little finesse, eh?

Re:The bigger issue

[Anonymous Coward]

"If the raw data is publicly available, it will give the people who want to deny basic science more ammunition for their inane babblings."

I start to get REALLY NERVOUS and suspicious when I am told that the full release of all information on a given issue will be too complex or difficult for the general public to understand.

Labeling skeptical people as "global warming deniers" akin to wacko religious fundamentalists, while convenient, does not negate the fact that there are intelligent people out there that just want to be able to verify what is being said on their own, without having to take Al Gore's word for it.

While global warming is a danger to humans around the world, I would feel more comfortable if there was clear cut, 100% proof that humans have caused it all, and that it is something we have the ability to fix. As this issue has polarized people so much, it seems to me that taking say, 500,000 years of actual climate data would be a good start to win people over, should it actually prove we as a species are causing all this havoc weather wise.

Re:The bigger issue

[dbrutus]

1. fewer people dying of cold.
2. easier/quicker ocean navigation due to new polar routes
3. less road/bridge corrosion due to less salt usage
4. coral reefs can be planted in new areas that haven't had them before
5. New agricultural lands in Asia and N. America will open up that should be a net positive on food balance

In general, there has been little to no work done on what would be an optimum average temp for the planet. In general, when we get colder (as in the little ice age) the economy goes in the tank and getting warmer (as in the MWP) provides an economic boost. There's likely a peak or series of peakes at some point(s) on the graph but we don't know what they are. The changes in global GDP numbers are pretty enormous.

I am in favor of finding out what the peak is and getting us to a level of space technology where we can launch shade/lense/mirror systems that will keep us at or near that peak, something of a global thermostat in order to maximize the utility of our environment. Once you get out of the "warm is bad" mentality and start searching for the optimum peak so we can get there, your brain will start to more easily register the upside.

Re:The bigger issue

[dbrutus]

A professional statistician (which is what McIntyre is) might not be able to check the underlying science but he might be better than the original climate scientist in applying cutting edge statistical analysis because that's *his* expertise.

An awful lot of science is multi-disciplinary that way, with data gathered for one field but bits and pieces of other fields being brought in to make sense of it. And those bits and pieces tend to be outdated. Economists, for example, regularly shake their heads at the economic analysis applied by political scientists. Mathematicians and evelotionary biologists have some similar friction.

So while the problem of analysis of data exists, there are plenty of cases where eyes from outside the specialty would do a lot of good. We should be very happy to see that sort of professional knowledge silo breakdown. Some people are less than happy.

Re:The bigger issue

[NickFortune]

Not to be elitist, but do you really think you could effectively review the data?

That, I think, depends on the assertion it's being used to support. I'm quite good at writing code to crunch large amounts of data and generate useful summaries. I wouldn't like to try and predict global temperature averages one hundred years hence. However, I think I could probably run up a quick sanity check as regards global average temperatures over the last century, for instance.

it may not be that urgent to make the raw data hyper-available to every guy on the street.

Forgive my saying so, but you sound like someone from 1807. I mean at one time, publishing this data would have involved significant effort. You'd have had to print up several telephone directory sized books to hold it all, and then distribute it using horse drawn carriages. And if someone asked me to marshall those sorts of resources, then I suppose that I too might enquire as the urgency of the situation.

The thing is though that this is the 21st Century, and a typical teenage girl probably uses up more resources in an evening's download of MP3s that it would take to publish this data. Hell, it's probably already on a networked computer; all it would probably need is a symbolic link and possibly a new entry in a routing table. I don't think "urgency" is a concept that really applies here.

As long as interested scientists - regardless of their previous conclusions or political leanings - can get the raw data when they want to review it, I think the process should work fine.

And do you think it is working fine? It doesn't seem to be; the intensity of the argument here on Slashdot stands as testimony to that, I feel.

Because so many people lack the highly specialized knowledge to make sense of the raw data, there are two types of information that are far more important to make widely available: 1) Education on how to be a climate scientist and 2) The conclusions that qualified climate scientists have reached.

All right - now you sound elitist. It's a bit like saying there's no need to publish computer source code all you need to do is know where the universities are; and to have access to programs written by qualified programmers.

Yes, credibility is the issue

[Anonymous Coward]

Otherwise, why link to admitted liar David Brock, and his Soros-funded Media Matters?

Immediate action??

[Russ Nelson]

Whenever somebody tells me that I must take immediate action, I reach for my wallet.

Then will someone explain to me...

[bagboy]

If the corrected US data doesn't indicate such a large statistical anomaly on a global basis, why are we blaming the US, US government, US Citizens for creating the massive global warming effect being reported? Sounds like we might be less of the cause then?

Re:Then will someone explain to me...

[marx]

It seems you've misunderstood the original problem. The problem is that the Earth can only tolerate a fixed level of pollution (greenhouse gases). This means that the global pollution output of all activities on Earth needs to be bounded by that fixed level. If you allow the pollution output to be proportional to the size of the global economy then the pollution output will not be bounded by any value, since the size of the global economy can grow (and does grow a lot).

You need to penalize wasteful production and consumption and a simple (and democratic) way to do that is to restrict each person to a fixed amount of pollution. You seem to want to suggest to restrict persons to different amounts of pollution, proportional to their share of the global economy. This would reward wasteful production and consumption rather than penalize it, since the more you produce and consume, the more you would be allowed to pollute. I don't really see how you can motivate such a viewpoint.

Like I said, if you allow pollution to be proportional to economic size, then producing an unnecessary hamburger and consuming it (or just throwing it away) would give you the right to pollute more. With a system with a fixed allowed pollution per person, then you would be rewarded by not producing the (unnecessary) hamburger in the first place, and you could instead "spend" your pollution on something which is actually useful.

Business as usual

[arivanov]

Fox and Co think that the world consist only of USA, news at 10.

They have looked solely at the USA graphs and completely ignored the world ones which are the ones that look really scary. They have also declared the problem with the USA data analysis to be a flaw in the data for the whole world.

Is anyone surprised? I am not...

Re:Business as usual

[ajs]

Fox and Co think that the world consist only of USA, news at 10. My problem with the debate (and this isn't new... it's at least 2 decades old) is that every time some conservative politician or news outlet waves some piece of information around (usually misunderstanding it badly), we immediately seek to use that to discredit the person or group who produced or publicized the information.

We desperately need to remember that scientists and politicians have an intersection, but the vast majority of them don't have anything to do with each other. A scientist who seeks to prove Einstein wrong isn't some Einstein-hating nutjob (typically). In fact, they're performing the most valuable task that the scientific method sets forth: seeking to disprove. By attempting and failing, we learn more about the value of a theory. By attempting and succeeding, we learn more about the theory's weaknesses, and often improve upon it.

Let's not start marching toward those scientists who seek flaws in global climate change research with pitchforks and torches (or rather, let's stop doing so), and instead seek to pressure the media and politicians into supporting them and their less skeptical peers without confusing the issue by politicizing results too early. We need even more funding than we have for those who seek to assail the consensus, not because we think it will fall, but because that's what the scientific method demands. Anything less is not science, it's just politics in a lab coat.

Whither the hype?

[dazedNconfuzed]

Ok, so 1998 was still the warmest - but not by more than a tiny fraction of a degree over 1934, and separated by a decrease to 1800s-era temps.

The bigger story I see in TFA's graphs is: we're looking at an increase of less than 1 degree C per century.
What's the fuss?

Re:Whither the hype?

[Ambitwistor]

The bigger story I see in TFA's graphs is: we're looking at an increase of less than 1 degree C per century.
What's the fuss? The "fuss" is:

1. The climate change so far is relatively small, but has already had noticeable impacts on ecosystems.
2. The amount of change is attributable largely (but not wholly) to human activity.
3. The amount of change is projected to accelerate in the future, based both on increases in human activity, the long atmospheric residence time of CO2, and the long term response being delayed by ocean heat uptake.
4. The damages (economic, ecological, and otherwise) are estimated to increase faster than linearly as a function of the climate change.
5. The damages are also rate-dependent, and the rate is projected to increase as in (3).

Honestly...

[Otter]

This had seemed like pretty much a non-issue all along. If anything it's Hansen's "second, more impassioned email" that diminishes his credibility as a sober, objective scientist just reporting his data. At least in my field, scientists don't issue corrections like:

Make no doubt, however, if tipping points are passed, if we, in effect, destroy Creation, passing on to our children, grandchildren, and the unborn a situation out of their control, the contrarians who work to deny and confuse will not be the principal culprits. The contrarians will be remembered as court jesters. There is no point to joust with court jesters. They will always be present. They will continue to entertain even if the Titanic begins to take on water.

Hansen muddied the waters himself

[Kohath]

I thought it muddied the waters plenty when he

- published incorrect data leading to incorect conclusions,
- refused to release his algorithm so it had to be reverse-engineered,
- and deliberately exaggerated the global warming threat to push his personal agenda (which he later admitted).

A solution to all of this FUD...

[_14k4]

Release the data, all of it, openly. NOAA data is available, for a fee to download I think, and so should all of the other data. I don't mean "should" as in "legislated", I mean "should" as in "should" or, "it would be nice."

If all of the data were released in this fashion, in one central "trusted" place, one could assume that as more and more analysts take a gander - themes will appear and more and more of the graphs could be trusted.

Carbon Credits stirred it up

[dbIII]

It went all weird once the economists got involved. Now both sides are talking about things based on little data as if they are certainties and the strongest opponents are grasping at tiny straws and saying that makes the entire thing worthless. What's more the most rabid opponents are saying that people in Antarctica are faking ice core results - a pretty stupid assertion really since they could fake the stuff at home where it is warm instead.

At least most people have given up on saying it isn't happening at all - a lot of opponents have moved to saying it's a purely solar effect. Watching the oil industry they are fairly split too so they can't be blamed - it's governments stirring up the mess and whether they are right or wrong Lysenkoism is taking over in US science and wreaking havoc. I would hate to be a climate scientist caught in the middle having the choice of either potentially career ending ridicule or government funding.

Re:Not global warming. Global climate change.

[Russ Nelson]

I'm sure that the next hundred years will be much less "interesting" than the previous hundred years, which saw the violent deaths of 250,000,000 people.

Re:Not global warming. Global climate change.

[Chris Pimlott]

because the total heat content of the of the earth, or "globe" if you will, and its atmosphere is expected to rise. likewise, you can talk about the increase in global longevity, even if not every country has a rising life expectancy.

Re:"Global" Warming

[jamie]

The maps he shows are global. You didn't RTFA.

Re:Cerial

[vidarh]

And you're illustrating exactly why he is outraged: The errors affected the US. The effect on the data for the global temperatures was so small as to be dwarfed by the overall margin of error for the data, but the media completely ignored that, and ignored that it changes nothing with respects to long term trends and overall global warming.

Poisoning the well, alive and well.

[bareman]

http://en.wikipedia.org/wiki/Poisoning_the_well

Someone drank the whole pitcher of kool-aid

[benhocking]

Although I love your Church references, the scientists did admit their mistake. They're not blaming the news organizations for reporting their error, they're blaming them for distorting their error. Understand the difference? Some news outlets pretended like this changed the whole "the 9 hottest years on record happened in the last decade" fact, when it did not. Prior to the change 1934 was the second hottest year in the US on record, and after the change it was the hottest year. Prior to the change several of the hottest years in the US on record were during the dust bowl, and after the change this is still true. The changes had no impact on which years were the hottest on a global scale, so the "9 hottest years" fact is still true. Do you understand how the right-wing media that you evidently get your talking points from distorted the truth now?

Re:Someone drank the whole pitcher of kool-aid

[rronda]

The issue of educating the press about how to communicate science works both ways. I wonder if people complain that much about the press coverage when 1998 was presented as the hottest year on record in the US, I wonder if the argument of the small area of the continental US was used in that case to explain the little significance that the US record has for the global temperature. That means that the "9 hottest years"-record that you are referring to is negligibly important for global temperature when the temperatures considered are only the US ones! I believe that a reasonable scientific stance is one of skepticism. No scientist is able to predict what the climate will be under climate change conditions. That would require for someone to know all inner workings of climate, and the magnitude and direction of all the feedbacks that models attempt to simulate. Of course the error in the data processing does not change the science of climate change. But that means that it leaves the state of the science of climate change exactly as it was before, that is one of uncertainty. And this is not what James Hansen is being teaching us for the last few years.

Re:Someone drank the whole pitcher of kool-aid

[dbrutus]

Sorry but according to the published standards, you are simply not supposed to have burn barrels next to your temp station. You are simply not supposed to put one of these things in the middle of pavement. These and other problems have been photographically demonstrated by the surfacestations.org effort. That's not a potential siting problem, that's a siting problem, period because the published standard that everybody agreed on many years ago says so.

If those are not actual problems, you should take out the language stating that such things are problems from your site standards. If they are problems, you should take out the stations that have those problems from your "high quality" list of sites.

Inconsistently applying data quality standards means your data is quite likely crap.

Re:Not global warming. Global climate change.

[rhakka]

Aren't you cute. The population has grown and at some point resources simply won't stretch far enough for all of us.

What exactly do you think is going to happen then? We'll all sit down, sing Kumbaya, and work out a peaceable solution, with the rich folk voluntarily slashing their standard of living so we can all subsist?

I think it would be pretty hard to say that unless we make some serious changes in the way we do things, 250m violent deaths will be the "good old days". Assuming we don't completely destroy ourselves while fighting over water, energy, and food.

I hope you're right, but I don't see the basis for your optimism.

So wait...

[SIIHP]

You're advocating "security through obscurity" for scientific data?

Really?

Because you think the downside of allowing the data to be easily available is worse that making sure it's accurate through peer review?

And that makes sense to you?

What kind of reasoning must one engage in to believe the idea that widespread peer review is not desirable because some nutters will misuse the data? THEY DO THAT ANYWAY.

Meanwhile, situations like this occur because the data is not easily available for review.

I simply don't understand how anything you said makes sense, or is in any way insightful.

why should I believe Hansen anymore?

[peter303]

Seems like a sloppy guy. Time to move on to more careful scientists, even if they are coming up with similar results. Thats what happens when you become too political.

Facts are hard to ignore... for most people

[sherriw]

Dr. Hansen gets it right on. His 2nd email: http://www.columbia.edu/~jeh1/realdeal.16aug20074. pdf is full of facts but most climate change deniers are highly skilled at ignoring those pesky facts.

I think that how humanity handles this issue will be one of the greatest measures of our species in our entire civilization's existence so far. I just hope we don't embarrass ourselves by bickering about this until it's too late.

About as tenuous as gravitation

[benhocking]

No, the AGW theory is based entirely on the tenuous idea that increased CO2 increases temperatures.

Good grief! Tenuous? Can you find a single scientific skeptic who denies that fundamental fact!?! (By scientific I mean holding a Ph.D. in a scientific, or even an engineering, field. Gene Ray, Doctor of Cubicism, doesn't count.)

Re:.001 degree?

[illumin8]

Well, at least he's not emotionally invested or anything.

Don't you think it's appropriate to be at least somewhat emotionally invested when it's the goddamn future of our children that is at stake? You and all the other global warming deniers can take a flying fuck.

Re:This man's career

[Ambitwistor]

is staked on perpetrating the "Global Warming" hoax. Oh give me a break. If you want to point out an error in his published research, go right ahead and try. Otherwise, drop with the insinuations and innuendo.

We were worried about the melting Greenland glacier, and dissapearing Arctic ice in the 1920's, too. So? It was warming in the 1920s too, just not as much or as fast as now.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:This SHOULD be about SCIENCE, but...

[Ambitwistor]

The goal posts are always moving. We can NEVER get a fixed set of predictions to hit or miss to prove or disprove the warming and/or human cause.

You're complaining because predictions improve? Sheesh. There's no pleasing you.

The central predictions for temperature change have remained largely the same, within the error bars, for 10-20 years. The predictions Hansen made back in 1988 have been borne out, if you pick the most accurate emissions scenario. A lot of the long term uncertainty is not in the climatology at all, but in forecasts of world economic growth. The climate predictions ARE testable and have been tested. And the evidence in favor of anthropogenic global warming has only increased.

The most-recent version of this is that we are NOW told there will not be any real heating until 2009 (AFTER the next US presidential election...so democrats can wave headlines around with doomsday predictions and not worry about being proven wrong before the election. hmmmmmmm)

That's not a different "version"; until now, nobody has tried to do a short term forecast with global climate models at all! Before now, the answer for the next two or three years would be "hard to say; we can only predict on decadal scales".

And spare me the conspiracy theories. This new prediction has nothing to do with long term climate policy, and wasn't even made by U.S. researchers.

2. "Warmest year ever", "Coldest year ever", "Warmest year on record", etc. Since modern weather measuring equipment has only existed for a brief flicker of time in the geologic scale, these phrases are just plain silly.

Scientists don't speak of "warmest" or "coldest" year ever. "Warmest year on record" is, however, meaningful. Geologic scale is not terribly relevant; whether it was hotter 100 million years ago has little to do with the current warming.

Even the thermometers used a few hundred years ago may not have been calibrated to todays standards,

That's right, and thermometers a few hundred years ago are not even used; the direct instrumental record only goes back about 150 years.

and while indirect things like sediments and tree rings may give clues they are even less-well calibrated.

They're less informative, but they're not useless, either. And even if we knew nothing at all about the pre-instrumental climate, that still wouldn't change the evidence that the modern warming is due to anthropogenic causes. Today is when we can most accurately measure the natural and human inputs into the climate system, after all.

If you cannot explain the past, your predictions for the future are just well-funded guesses. Until supporters can tell us what EXACTLY caused all previous warming and cooling patterns, they cannot honestly claim to understand the mechanisms well enough to properly predict the future.

That is an absurd requirement. As noted above, you don't have to have a perfect understanding of the past in order to have a good idea of what is happening now. No one will EVER tell you EXACTLY what happened at all times in the past, nor do they need to. The mechanisms operating on geologic time scales are only tangentially relevant to the present climate on centennial scales. Understanding paleoclimate events helps, but it's not a necessary requirement.

Supporters of the global warming claims want to force entire societies to change in dramatic ways. They want political changes and societal changes that will have sweeping effects. Many average citizens will lose jobs, and homes, and marriages. Industries will be halted/moved and allocation of resources will be shifted.

You are grossly exaggerating the impacts/costs of mitigation (and ignoring the impacts/costs of climate change).

We are told the US is the biggest contributor (the BIG SINNER) but as soon as problems are found with the US data, we are told that the US numbers have lit