There does not need to be a 'quantity' of evidence. Merely that the evidence can be refuted (not taken at face value). A 'proof' is what I associate in popular media with scientific evidence. 'Think' is code-word for: hypothesizes. Especially when the weasel words 'may', 'might', 'could' appear.
W.r.t. qualifications I think the answer should be obvious. I am addressing (as a layman) the mode of communication as it appears in popular media, and try to distance myself from the contents of whatever is communicated.
> My fear is we're quite possibly terribly damaging the planetary ecosystem. That's pretty black and white to me.
Yes, that fear is on my mind as well. There is irrefutable evidence in coral bleaching and there are other globally occurring phenomenon. And because of that, we need to be extra careful on how we convince our fellow earthlings.
> > Most climate scientists are not on either end.
> If you are going to claim this, please back this up when you say it. Claims without references are useless.
Well, it depends on how you define 'the ends'. There are those who believe we are all going to die within a decade. There are those who reject all evidence. There are those who believe it is irreversible and those who think we are able to cope.
So, this is on the predicted effects of climate change and its extend. Most models are relatively accurate globally, but subcontinental predictions can still be way off (2-5 degrees either way).
In my opinion, the media goes either way: left wing brings us doom and gloom scenario's, while right wing paints a rosy picture. That should be a clear sign that we are not making progress. We should be finding common ground! I believe the viewership still has common ground, but the media is creating a Babylonian tower.
Then there is the whole discussion about what to do about it. People come up with all kinds of ideas, such as carbon tax (how to deal with CO_2 from imported products), solar panels (could be a real option, but requires heavy investing in infrastructure), biomass, political and diplomatic approaches, underground storage, etc.
And each of these approaches comes with another doom-and-gloom story, connected with these 'solutions'. Consider what it does for the non-scientific oriented population. Climate is now seen by many as a means to push products. Many switch to ignore mode.
Take this [1] article in National Geographic for example. It's all due to climate change! Not a word on bad forest management, bad water management, increased population density and more. It's outright duplicitous to not mention the other factors. And it's also sad, because the 'opponent camp' can now point at these articles and say: "You see! This is what they feed you!". Global warming is calculated to be around 24% accountable for these wild-fires.
> > However, there are many secondary and tertiary effects.
> These being...? Specifically?
Precipitation is still very difficult to model. Increased temperature means increased evaporation, increased cloud cover and increased precipitation. It depends on what kind of cloud cover is generated whether this will have a net cooling or heating effect.
Another factor is the mixing of salt and sweet water, which due to the melting of the polar ice has effects that, if I'm not mistaken, is not yet precisely modeled.
We can accept that we are putting ourselves at risk. However, I am sure we will come to the right conclusion faster if we let people make their own conclusions and not make this into a polarizing shouting match.
[1] https://www.nationalgeographic.com/environment/2018/11/clima...