Everyone who can hear this has already heard it. Those who continue to pretend it is not happening are either deliberately deceptive so they can continue to make money from fossil fuels or unable to change their minds when faced by evidence due to identity politics.
My impression is that almost no one denies the warming itself, just the link to greenhouse gasses. That link is unfortunately much harder to prove than rising temperatures by itself. The proof is there nonetheless, but it's easier to cast doubt on it, and that's what certain groups have been doing.
I've seen the full-court denial:
- it's not warming, or not significantly
- if it's warming, it's not because of humans, (or)
- if it's warming, it's beneficial
- if it's warming because of humans and that's bad, there's nothing we can do about it
ETA: honorary mention for "what about China?"
People I've argued about this with will switch interchangeably between these. Press them hard enough on one issue, and they'll just switch to another. It's a game of whack-a-mole.
Or "Why does 2 degrees matter?"
Because when were 4 degrees cooler, NYC was under 1000 feet of ice. We really don't want to find out what 4 degrees hotter is like.
Wait really? 1000 feet is insane.
It was actually about 2000 feet. The Laurentide ice sheet, it was 3 kilometers / ten thousand feet thick in some parts.
Same here. I'd also add "It's warming, caused by humans, harmful, but mitigating it would be even more harmful."
Basically, anyone capable of thinking about it logically has at this point reached the conclusion that it's real. Anyone arguing otherwise is therefore necessarily not thinking about it logically, and you have to expect things like shifting claims.
But POTUS 5 months ago:
"If you look back years ago in the 1920s and the 1930s, they said global cooling will kill the world. We have to do something. Then they said global warming will kill the world, but then it started getting cooler. So now they just call it climate change because that way they can't miss. Climate change because if it goes higher or lower, whatever the hell happens, there's climate change. It's the greatest con job ever perpetrated on the world, in my opinion. Climate change, no matter what happens, you're involved in that. No more global warming, no more global cooling. All of these predictions made by the United Nations and many others, often for bad reasons, were wrong. They were made by stupid people that have cost their country's fortunes and given those same countries no chance for success."
https://rollcall.com/factbase/trump/transcript/donald-trump-...
> "that have cost their country's fortunes and given those same countries no chance for success."
This is a weird statement coming from Trump. I wouldn't think his base would care for improving the lives and economies of other countries, specially undeveloped countries.
He frequently has campaign rallies and press conferences where he makes statements on both sides of the issue, though if the audience is limited he will tailor the message so only the side present hears the argument in their favor. Every post speech interview I've seen and heard from Trump supporters discount every thing he says that they personally disagree with and heartily approve everything he says that they agree with. Somehow he has insulated his own actions/words and his supporters, and it makes it difficult to reason with these supporters when you bring it up to them - it's quite uncanny.
I mean, he's saying everyone else who tried to do something about climate change had bad results, so let's do nothing and we'll be better off.
Doesn't seem weird to say that if you want to do nothing.
> My impression is that almost no one denies the warming itself, just the link to greenhouse gasses. That link is unfortunately much harder to prove than rising temperatures by itself.
The link to greenhouse gases is not hard to prove. We've got satellites that can measure global radiation inflow and outflow and see what the difference is. We can also measure this at various levels within the atmosphere, and at the surface of the land and oceans. We can see where outgoing radiation is getting caught and we can see what frequency bands of outgoing radiation is getting caught.
We know the frequency bands that get reflected, absorbed, or pass through for all the gases in the atmosphere and can see that the gases causing the problem are the greenhouse gases.
We can also see that the increase in greenhouse gases is mostly from burning fossil fuels. We can see this by looking at the isotope ratios in the C in greenhouse gases.
Cosmic ray bombardment in the upper atmosphere produces carbon 14, which is radioactive with a half live of 5730 years. It disperses throughout the atmosphere and becomes part of anything that regularly incorporates atmospheric carbon or exchanges its carbon with atmospheric carbon, including all living things.
Everything humans do in significant amounts that puts greenhouse gases in the atmosphere other than burning fossil fuels has carbon with about the same isotope ratio as that of the carbon in living things. Even when we burn a dead forest to clear it out the isotope ratio is close to that of living things, because of that 5730 year half life for carbon 14.
It is only when we burn fossil fuels that we put carbon into the atmosphere with almost no carbon 14. They came from living things but have been dead long enough for hundreds of half lives to pass.
The isotope ratios in the excess greenhouse gases show that it is mostly carbon 14 free. There are natural processes that can dump carbon 14 free carbon into the atmosphere such as volcanoes and other geological processes. However, (1) the increases in carbon 14 free greenhouse gases matches very closely with the amount of carbon we've been emitting from fossil fuels, and (2) and monitoring of volcanoes and other natural sources doesn't find nearly enough to account for more than a small amount of the increase.
I didn't even think the link to greenhouse gases is denied any more.
The merchants of doubt ran out the clock and what I hear from the former deniers I know is that it is too expensive and too late to do anything now, being warmer will be nicer, and CO2 is a fertilizer.
A friend of mine says he was convinced by https://xkcd.com/1732/
Even the qualification "in the last 10,000" years gives the doubters something else to dismiss global warming.
There are people that believe the warming, but don't believe it matters because the Earth used to be much hotter at some point in the past so it is a natural cycle. Yet they fail to realize that humans didn't exist then so there is no good reason to believe an Earth that hot can support human life.
>> My impression is that almost no one denies the warming itself, just the link to greenhouse gasses.
I fall in that category. My suspicion is that water vapor from air travel is by far the biggest contributor. I saw the blue skys after 9/11. I read the NASA guys that said daily temperature range increased measurably. I saw the blue skys again during Covid19.
I'm also of the opinion that anyone looking at historical data only going back 200,000 years or less is missing the larger picture. Sea levels are NOT at historic highs, we should expect them to rise further before receeding. We should expect glaciation again if we don't do anything, but speeding up warming IMHO is more likely to trigger glaciation that to "push through" whatever causes it and break the cycle (which would be a good thing).
So as a long-term thinker all this hype is just that. If you don't have a plan to end the glacier cycle you're just making a big deal out of a small change in time-scale due to reasons (CO2 vs H2O) that may well be the wrong ones.
Not to be contrarian, but if you cared, you could easily rule out your suspicions.
It's not even worth it to say why or how, since not even doing rudimentary research means that you aren't interested in developing a well-informed opinion.
>> Not to be contrarian, but if you cared, you could easily rule out your suspicions.
That's just false. You might try to rule it out yourself to see. My comments here and the responses demonstrate that it's a waste of time to argue against people in the purity cycle of global warming. My position is one of moderation not denial - and I'm downvoted, told I don't care, and I haven't done even the minimum of research. Pffft. HN is not what it used to be.
You are being down-voted not because of some imaginary "purity cycle", but because you discard without reasoning a vast amount of evidence to the contrary of your hypothesis.
You've heard of the saying that extraordinary claims require extraordinary evidence? Holding a hypothesis of water-vapor from air travel being the primary driver of warming trends is extraordinary.
Invoking the oft-repeated "do your own research" rhetorical crutch and referring to scientific consensus as "hype" doesn't help your case.
It took me about five seconds to find this: https://climate.mit.edu/ask-mit/why-do-we-blame-climate-chan...
Do you have any reason to believe otherwise besides a couple of anecdotes about looking at the sky and short-term temperature variations?
> My suspicion is that water vapor from air travel is by far the biggest contributor.
Have you calculated the water vapor generated from air travel, and compared that to the water vapor already generated by the water cycle? (just normal evaporation from lakes/rivers/oceans/plants)
Even as back-of-napkin math, this should be a pretty easy sanity check.
I think you're off by a few orders of magnitude here, but I also don't want to discourage you from adopting a "check for yourself" mindset.
>> Have you calculated the water vapor generated from air travel, and compared that to the water vapor already generated by the water cycle?
I've SEEN the effects with my own eyes. You can also see contrails seeding cloud formation on some days. Then there's the fact that these extra clouds are formed and dissipate on a 24 hour cycle, so part of the day they let in sunlight and part of the night they trap heat. These effects are significant and there is little research on the bigger picture effects of this (that I've seen).
Clouds reflect radiant heat back into space. Contrary to your claim, "global dimming" was a very active research space for a long time, and in fact the water vapour and other airborne pollutants likely masked the impact of global warming.
How significant? Give me a number. What percentage of all the clouds in a day come from planes?