When I was a child it was the ozone layer.
That's because there WAS an expanding hole in the ozone layer and then the largest global cooperative effort in history banned the use of the chemicals responsible and the issue improved. This is actually a counter-example to your point, not support for it.
For my parents they were told we were headed for an ice age.
I highly doubt that they were told that consistently (because they weren't, that was a fringe theory), but we WERE on track for a natural cooling period EXCEPT that this cycle was and is disrupted by greenhouse gas emissions. This is discussed in most relevant science on the subject including in the old oil company research that I linked literally one message up: Shell's own internal communications explicitly rejected the "coming ice age" crank theory that was making the rounds at the time as a counter to the CO2 theory as did other scientists at the time.
Lots of theories but they keep changing the message.
No, the scientific messaging on this has been extremely consistent since the 70's: greenhouse gas emissions is making the planet warmer and is going to have effects including but not limited to stronger and more frequent storms (check), disrupted weather patterns (check), collapse of local ecosystems, replacement of permafrost with seasonal ice (check), rises in sea level from the loss of the permafrost (check), and all that is going to have knock-on effects towards human society.
Effects like, oh I don't know, coastal cities at sea level seeing greatly increased seasonal flooding due to many of the above.
What you think is "changing the messaging" is a combination of admitted uncertainty inherent to modeling large-scale chaotic systems, normal disagreement over minor details, but more relevantly an intentional large-scale decades-long astroturfing campaign by the fossil fuel lobby trying to fool people like you into thinking that this isn't a problem. The only real differing opinions are on timescale, overall severity at any given, and micro-effects as opposed to macro-effects.
Oh and at what point we can no longer do anything about it, that's in debate too.
No doubt the climate will change it always has, but we are still basically idiots when it comes to predicting anything.
No, the predictions have actually been pretty good for such a large and hard to model system as the global climate. YOU don't understand the predictive model so you say things like this, so that you don't have to think about it, change your opinion, or lift a finger to do anything.
The people invested in Green Tech seem have tons to lose if people arent on message.
Not
nearly as much as the fossil fuel companies have to lose if every competent scientist in the world, NASA, every branch of the US Government (including the military) who has independently looked into this, every other government of a developed country in the entire world,
and the oil companies themselves, all turned out to be right.
You get how stupid your conspiracy theory sounds when examined closely, right? That "the green tech people", whoever they are, have managed to somehow make up a threat that has fooled
every government in the world and every competent scientist acting in good faith in the world (including the ones that work for the fossil fuel companies!) to maintain their strangehold on... a
tiny amount of market share compared to the fossil fuel companies that continue to dominate the energy sector? Seriously?
Go google "occam's razor" please. The most likely explanation and the one that actually has the most evidence is that climate change is real and that the fossil fuel lobby and associated industries that depend on it have been spending an enormous amount of money and manpower to slow or stall legislation and public support. Hell man, I literally posted links to documents that show them talking about this in the 80's in the comment above yours. This isn't hard math, bro, Big Windmill isn't the issue here.
Similar to what we just went through with big pharma.
Pharma is a GREAT example but not for the reasons you think. They routinely spend enormous sums on regulatory capture and hiding the dangers of their own products from the public, to a lesser extent than the fossil fuel industry but same playbook. Perdue Pharma's lobbying and public obfuscation of the extreme addictiveness and dangers of oxytocin kicking off the current opioid epidemic is actually a decent but not perfect parallel for what the fossil fuel companies have been doing in regards to lobbying and obfuscating the effects of greenhouse gas emissions for corporate profit.
Again, this is a great counter-example for your point of view, not support for it.