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I absolutely don't believe that human-created CO2 emissions cause global warming. However, I consider myself a staunch environmentalist.

I believe we should be doing whatever we can to control pollution. It sickens me that factories pump out pollution, that we can barely eat fish anymore because of all the garbage and poisons we pump into our oceans. I think we need very strict controls on every form of pollution as well as garbage and creating plastic waste (including microplastic particles in our oceans), although I do believe CO2 pollution is on the bottom of the scale in terms of importance. I believe that fines for factories that pollute the environment should be material, ie. very heavy relative to yearly revenues. Personally, I do my best to ensure that I create as little waste as possible, and that I do my part in terms of recycling, composting, etc.

So I consider myself an environmentalist, I just don't believe that global warming is caused by human activity, and CO2 pollution is the least critical of the pollutions.




Can you explain your lack of belief when 97% of climate scientists (there's conflicting data on this; some reports show as high as 99%) agree that human activity is causing global warming?

EDIT: That's not rhetorical. I'll entertain any logical reasoning you have as to why your reasoning is superior to those educated and practicing the subject daily.


I thought the 97% of climate scientists claim (based on Cook et al) was shown to be a really flawed study. In any event, Consensus does not equal science.

I think given the broad definition of "human activity is causing global warming", you'd be hard pressed to find disagreement. If you refine it to "human activity is causing a majority of global warming and that warming is bad" there is a lot less agreement.


>I thought the 97% of climate scientists claim (based on Cook et al) was shown to be a really flawed study.

Only according to really flawed and biased sources.

>In any event, Consensus does not equal science.

Actually science is very much the consensus among practicing scientists.

Short of reproducing millions of man-hours of international research to verify or refute it personally, what exactly would be the alternative?


Science is about finding truth. Truth doesn't give shit what anybody thinks. (Except in psychology, but lets not get there.)

Scientific consensus is just educational and political tool. Get everybody on the same page. But it's pretty detached from the actual process of science itself.

Questioning established consensus has been scientifically very valuable in the history.


>Science is about finding truth. Truth doesn't give shit what anybody thinks.

Truth is an abstract concept. You can't get hold of "truth" in raw form. Consensus is the only thing that validates a statement, and scientific consensus, that is consensus among experts following (each perhaps imperfectly) the scientific method, is the only thing that validates a scientific statement.

Even direct experience is not some failsafe -- a single person might just be misinterpreting, lacking skills and knowledge to understand what you see, or plain delusional (e.g. Wilhelm Reich and orgone or Linus Pauling and vitamin C).

>Scientific consensus is just educational and political tool. Get everybody on the same page. But it's pretty detached from the actual process of science itself.

Not according to any philosophy or practice of science that I know of.

>Questioning established consensus has been scientifically very valuable in the history.

Sure, but only to establish a new consensus, not to say that "my sole opinion, that remains my sole opinion, is more valid than the rest of the scientific world's".


> Actually science is very much the consensus among practicing scientists.

Unfortunately, philosophers of science might add. They'd observe that a good determinant for a new theory to prevail over an old one is, well, when the old guard retires.

Not discounting the value of scientific literature mind you. Or the fact that we've indeed been seeing what looks like warming of late. Merely pointing out that a consensus does not a Truth make, that the consensus has remained unchanged since the 1970s [1], that the bloody mess is rather chaotic in nature, and that we're still learning new things about it every year.

[1] https://en.wikipedia.org/wiki/History_of_climate_change_scie...


Consensus of scientists studying a given subject may not "equal science", but it's basically how scientific facts are established. That's how science works. There are always at least a few skeptics and crackpots, can never be free of them entirely.


I have trouble taking either statement that seriously. We do not have a baseline to compare against as there is no spare earth available that is untouched by human hands.

The question has to be considered primarily from a qualitative point of view. The only reason people discuss the science so much is because they lack good instincts about the environment. It is so easy to believe that humans are an insignificant part of the environment when you entire world is made by man.


Maybe they forgot a keyword? It certainly isn't the sole cause of global warming/climate change, but it is real.

CO2 in the atmosphere--what's historically known as the greenhouse effect--leads to earth's warming. CO2 emissions are also undeniably connected to the the greenhouse effect, which we clearly have a role to play in. That's science that no one disputes.

But somehow people come out of the woodwork as climate change denialists.

It doesn't really make sense unless seen through a political lens, since politics is antithetical to science in a lot of ways.


There are serious skeptics. Like you say nobody really disagrees with 1) humans release more c02 and 2) more c02 = warming via greenhouse.

But that isn't the entire global warming theory.

There are many feedback effects that occur. Like warming -> melting ice -> water vapor from condensation -> water vapor is a greenhouse gas -> more heat

But there are negative feedback effects too. Like warming -> melting ice -> less reflection of sun -> less heat

So many people are pushing theories with high feedback multiples. Some people are pushing theories with high negative feedback.

Depending on how you model the feedbacks--Climate change can either be a small issue with a degrees or two warming or a mass extinction event with 5 degree C warming.

The problem is it is very hard to test the models.


Other factors don't contribute much. It's real, it's human made and dangerous:

http://www.bloomberg.com/graphics/2015-whats-warming-the-wor...

The state of CO2: now around 400 ppm, 20 years ago was 350 ppm, and that was already more than during the last 800 thousand years, and now it's increasing unbelievably faster:

http://assets.climatecentral.org/images/uploads/news/11_19_1...

(based on http://cdiac.ornl.gov/trends/co2/ice_core_co2.html )

http://assets.climatecentral.org/images/uploads/news/11_19_1...


If 5 degrees is a mass extinction event (I'm just using your numbers here, not positing them as facts of my own), how can you characterize 1-2 degrees (20-40% of your mass extinction event number) as a "small" issue?

As an "engineer" (note: software engineer, not a real engineer), I'd prefer to leave as much wiggle room as we can possibly muster on the spectrum of activities heading us towards "mass extinction event".


Actually "warming -> melting ice -> less reflection of sun -> less heat" would go other way around. If you have light surface it's likely that lot's of visible light is radiated to space. If you have blue sea instead it's likely it radiates only infra red. Which would be bad with elevated CO2 levels.

The most believable negative feedback I have seen is about increased cloud coverage. Clouds should then reflect visible light back to space. At the same time water vapor is the most significant greenhouse gas in the atmosphere. We really don't know how it's going to turn out.


I suspect simply because the 1-3% who are skeptical are literally excommunicated from the scientific community. The problem is that it requires a belief. While we have evidence, there is no conclusive proof, since it's it is difficult to "test" in this field of science.


This is science, not math; there's no such thing as proof; evidence is all there ever is. Seeking proof is to misunderstand the science completely.


Cook should do surveys for these questions too (and include replies from more than 100 people):

If human activity is causing global warming, is that a good or bad thing?

If that is a bad thing, does it present an existential threat to our civilization?

If it presents an existential threat, is it the most significant existential threat our civilization currently faces?

If it presents an existential threat, can our civilization do anything about it?

Where does the danger of global warming rank compared to the danger of, say, population growth? Other pollution? Terrorism stuff? Nanobot grey goo?

If our civilization can do something about an existential threat from global warming, could a cap-and-trade or some other kind of government policy be a good solution?

If etc, could the dynamics of our culture, markets, or technology be a good solution?


I'm sure a large majority of nutrition scientists supported a low fat diet 20 years ago. (Food for thought)


> I'm sure a large majority of nutrition scientists supported a low fat diet 20 years ago. (Food for thought)

Sure, and a large majority of physicists supported General Relativity 20 years ago.

If your point is that vague analogies aren't helpful and specifics are needed, I think that was precisely what toomuchtodo was getting at.


General relativity I much easier to test in simple systems, like planets traveling in the vacuum, or to get more precision you can test it in the lab https://en.wikipedia.org/wiki/Tests_of_general_relativity . I'm not sure if this is the more accurate current test but from https://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment :

> The result confirmed that the predictions of general relativity were borne out at the 10% level. This was later improved to better than the 1% level by Pound and Snider. Another test involving a space-borne hydrogen maser increased the accuracy of the measurement to about 10^−4 (0.01%).

Nutrition and diets are more difficult to measure (you can't enclose a few thousand persons in the lab for 20 years) and it's full of side effects and interactions. IIRC a low fat diet is still recommended. I think that a better example of the changes in nutrition is the butter vs margarine recommendations, see for example http://www.telegraph.co.uk/news/science/science-news/1179683...


Most nutritional claims are based on pretty thin evidence and even more scant data.

The climate researchers are able to dig back literal millions of years and chart their findings.


> The climate researchers are able to dig back literal millions of years and chart their findings.

sorry, this is pretty funny. Do you know what the data those charts of millions of years are based on? models based on thin evidence and scant data. We are talking like 10 ice cores and 5 trees will swing the data wildly.

I am not a denier (CO2 causes some warming!) but this comment was kinda funny.


I'm surprised you're being down voted.

Remember the "global warming hiatus" that happened over the past 15 years? The one that most climate scientists accepted? Well, it looks like the models we're wrong. Tweak a few model input and "oops!" it's actually been warming the last 15 years.


They still do. People who tell you carbohydrates are the problem have something to sell.


exactly! pssh science, what good is it? /s


For decades, scientists, doctors and dietitians said that eating fat caused heart disease, and you should decrease your fat in your diet. Only in the last couple of years has this "fact" been deemed wrong.

I don't think you would have found a single scientist, doctor or dietitian since the 70s that would have disagreed with the above. It was taken as fact and anyone who thought differently would have been a laughing stock.

The same goes with global warming caused by CO2. It makes for an easily digestible theory, but it doesn't explain many known facts. Global warming caused by CO2 has never been proven, obviously, since you can't do experiments on a global scale. So there's already a lot of faith that you would need to take into consideration. There's circumstantial evidence at best. But still a lot of unknowns about climate and the vast changes that the Earth has undergone over the last 6B+ years, so to say that we know that the current warming trend is caused by CO2 to me is not science.

If you read this thread, it's humorous to read all of the people who think that there is data going back millions of years that links CO2 to climate change. It's a great example of how regular people just take whatever is spoon fed to them without thinking "really, does that make sense?"

For example, North America was covered in ice at one point, and the temperature increased dramatically over the last hundreds of thousands of years. What caused this, and could the same process be responsible for the warming we have seen in the last several decades?

The 5000 year old Iceman found in the Alps attempted to cross the Alps when there was very little snow. We know this because of the clothes that he was wearing when his body was found. So obviously the climate was much different 5000 years ago than today. What caused this change, and could the same process be responsible for the warming we see now?

We know that during the Medieval Warming Period, it was a lot warmer than it is now. What caused this change, and could the same process be responsible for the warming we see now?

I would like these questions answered before I change my opinion. As a man of science, I see too many people flocking like sheep to the answer of CO2 causing climate change. Just like the whole fat-in-the-diet belief, too many people don't really think, they assume that the scientists are right, which is not thinking, in my opinon.


>If you read this thread, it's humorous to read all of the people who think that there is data going back millions of years that links CO2 to climate change.

Except... that data does exist. Sediment cores do contain evidence of past levels of atmospheric carbon dioxide to a fairly high degree of accuracy, and we have sediment cores going back up to about million years ago, or so.

>Global warming caused by CO2 has never been proven

Sure, you can't do a double-blind randomized control experiment with the earth, but when two variables are clearly correlated with a time difference, over millions of years, controlling for confounding factors, it's pretty clear that one causes the other.

>For example, North America was covered in ice at one point, and the temperature increased dramatically over the last hundreds of thousands of years. What caused this, and could the same process be responsible for the warming we have seen in the last several decades?

According to Scientific American [1], the last ice age ended because of a rise in atmospheric carbon dioxide.

[1] http://www.scientificamerican.com/article/what-thawed-the-la...


Except correlation doesn't prove causation. How many times does this have to be stated for people to understand this? The number of pirates is perfectly inversely correlational to the atmospheric CO2. Is it pretty clear that one causes the other?

Sediment cores and being able to extrapolate data going back thousands or millions of years is a theory only. No one can state CO2 levels going back thousands of years with any level of certainty, certainly not in the Ppm accuracy.


Maybe he has a basic understanding of time series analysis:

https://en.wikipedia.org/wiki/File:Vostok_Petit_data.svg


Notice that the last value in that graph is around 280 ppm, and that it doesn't exceed about 300 in the entire graph (about half a million years).

Current CO2 levels recently broke 400 ppm and still rising.

To represent the current situation, you'd need to add a spike at the end roughly double the height of that graph.


Does the temperature trend have a similar spike?


Yes. It's not as far out of the historical norms as CO2 levels, but the gradient on it is astounding. It's taken us about 100 years for temperatures to rise beyond their last peak, which occurred about 7000 years ago [1]. Note that this is precisely coincident with the rise in CO2.

It's true that there's a historical feedback loop between CO2 and temperature, which operates in cycles. But we are now operating far beyond the usual range of that system, whatever it is, and nobody knows exactly what will happen next.

[1] https://www.climate.gov/sites/default/files/styles/inline_al...


The wikipedia chart covers 450 thousand years on the x-axis, and a 14 degree range on the y-axis. Your chart covers 12 thousand years on x and 2 degrees on y. If your chart was shrunk to the same scale and overlaid on the first chart, it would be lost in the noise, and your astounding gradient would be nothing compared to the rises and falls 20K and 140K years ago, among others.

Very disingenuous of you.


Why did anybody said the response is linear?


The point of that chart is that the temperature appears to go up before the CO2 levels, leading to the theory that higher temperatures (due to natural cycles, perhaps solar activity cycles) heat up the ocean and other CO2 sinks, leading to a rise in atmospheric CO2.


He has infinite wisdom that failed the 97% of the scientific researchers who make it their profession to review this stuff.


All of the surrounding doublespeak is deplorable. We are expected to treat these all these terms as being synonymous: "climate change", "global warming", "human-created CO2 emissions". If you deny one of these, you deny them all.


What if you're wrong? CO2 may lead to a runaway greenhouse effect, making the earth uninhabitable in the long run (turning it into a Venus look-alike).

I don't think we can risk this outcome (and the extinction of our race) just because because a couple of people think CO2 may not cause global warming.


I don't think an environmental Pascal's Wager is a strong position to base actions on. Reducing emissions will have a strong effect on our societies and people's lives (and global economics), so it's important to weight things properly.

Not saying you're wrong, just that criticisms of Pascal's Wager have validity.


> Reducing emissions will have a strong effect on our societies and people's lives

Let's be a bit more concrete about this. In the near term, reducing emissions is going to reduce economic output. That is literally going to kill people. (The stress of poverty kills people. Lack of money to pay for food and healthcare kills people. So unless you've got a redistribution scheme that you can make actually happen in the real world, reducing economic output means killing people.)

That's the other side of this "Pascal's Wager". If we run off and cut emissions before we know how to do it without reducing economic output, more people that we would like are going to die. They're not going to make headlines, because they're going to be marginal people in marginal places... oh, yeah, the same kind of people who are going to die (first) from climate change.

It may be a net win to fight climate change. But don't act like it's completely one-sided.


It will be easier to change our current ecconomic system than the environmental systems.


But we don't know that the endgame is extinction of the race. We don't even know when various benchmarks will occur ( say, sea level at x% higher ) .

The physics of a Venus aren't on the table - SFAIK, all the carbon we're digging up and burning was once animal or vegetable matter, derived from a Carboniferous era level of atmospheric CO2.


It's no longer a matter of belief, the evidence is in, the overwhelmingly vast majority of climatologists say you're wrong; end of debate. Now it's time to do something about it.


I think that's a terrible idea.

For hundreds of years, people thought stress and food caused ulcers. It was scientific fact and if you doubted it, you'd likely be labelled a crackpot. Until a scientist in Australia proved ulcers were caused by bacteria.

So consensus was wrong. Very wrong.

I'd prefer it if people kept questioning everything. How else do we push forward our knowledge?


The thing that I hate about this argument of 'consensus has been wrong before' when it comes to climate change is that essentially, the argument seems to be 'everyone always said we were pumping too much CO2 into the air and that would cause global warming and now there's people saying that consensus is wrong'.

Unless I'm seriously wrong with my scientific history (and it's extremely possible!) I didn't think this was the case. Decades ago there were people talking about it but the consensus was that it was crackpottery.

However now that consensus has decided "yeah, we were wrong" people point at that consensus and say "hey, consensus has been wrong before!". I look at that and just think... yeah, we know. It was wrong and we've spent a heap of time finding that out.

I mean, it's not the case that 100% of people knew it as a 'scientific fact' that CO2 lead to climate change and now we're starting to question that consensus. The questioning has already happened.

Or I completely wrong in this?


But I think that's true of everything, no?

Before people thoughts ulcers were caused by stress they probably thought it was due to too much "humor" and required treatment by bloodletting.

The point is that we advance scientific thinking by challenging ideas. If right now most scientists thinking global warming is real, then fine. Just don't try and shutdown the ones that don't agree.


No one is trying to shut down scientists that don't agree; they're trying to shut down the ignorant public who's non agreement is baseless because they're getting in the way of setting public policy based on the best information science has to offer us at the moment.


That is a problem that will never go away. You will always have someone spreading incorrect information and "getting in the way" (vaccines cause autism, etc).

If the global warming data is as rock-solid as they, I wouldn't worry to much about it.


Yeah, that's a good point and I see where you're coming from. But generally when I hear the argument about consensus, it seems to end with nothing other than an implication of "and therefore they're obviously wrong, simply because of the current consensus".

But yeah, I see your point.


People should keep questioning. But it's time to stop the faux-modesty of "we might be wrong so we shouldn't do anything". We make the best decision we can based on the evidence at the time, and if the scientific consensus is right (which, while not certain, is very likely), we can't afford to do nothing.


Scientists should always continue to question everything when doing science; the general public however is not in a position to do this and they should follow the consensus of scientists when setting public policy. You can't wait forever when making policy, so you go with the current best knowledge.


Until a scientist in Australia proved ulcers were caused by bacteria. So consensus was wrong. Very wrong.

Interestingly, among people who have Helicobacter pylori in their stomachs, only a subset develops ulcers. Some people have bacteria, but no ulcer. I don't know if there is a consensus on why this happens, but it is correlated with stress. If you are stressed and have h.pylori, you are more likely to develop an ulcer, compared to h.pylori and no stress.

So the consensus was wrong, but still not a hundred percent wrong.

Source: Why Zebras Don't Get Ulcers, Third Edition http://www.amazon.com/Zebras-Dont-Ulcers-Third-Edition/dp/08...

Quite a fascinating book on stress.


I downvoted you, not because I disagree with you, but because you have your head in the sand. Not believing in human caused global warming at this point is like not believing in the germ theory of disease. The weight of evidence against that position is so insanely lopsided that the only way is possible to defend it is out of sheer ignorance. Please educate yourself on the topic so people don't laugh at you behind your back.


"I dont't belive..."

Believe, the magic word, makes it a religion basically. I'll take the sceintific consensus. They have evidence.

http://climate.nasa.gov/evidence/


Regardless of one's stance on global warming and whether or not humans contribute to it, I would hope that we can all agree on the necessity of environmental stewardship. It's deplorable that many bodies of water cannot be swam in (let alone fished from), that breathable air which does not contribute to asthma and lung cancer is a luxury, and most of all that this happens because corporations place the cost of these externalities on society without adequately paying for it.


Great, you don't need to believe it.

Being that it is the observed reality of the world, the causal link between human industrial activity and global warming exists no matter who or what believes it.

Since it sounds like you'd support policies that encourage pro-environmental action anyway, I'm happy for you to believe whatever you want.


What about ocean acidification, which is also a very-dangerous effect of increasing atmospheric CO2 levels?




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