Humanity as a species won't end due to climate change. That's a ridiculous assertion. Full scale nuclear war probably couldn't wipe us out completely. Global warming can't either. Billions might die, but humanity will survive almost certainly.
Maybe, maybe not. If you want to split hairs then, how many billion people do you think it's acceptable to kill or cause to suffer so we can have iPhones?
People are very bad at estimating the probability of catastrophic events. We base our estimates on things that have happened in the past, but that doesn't help predict things that have never happened before. Hundreds of millions of years of pent up carbon have never been released into the atmosphere over the course of a couple centuries before. It is hubris to the point of suicidal to think anyone can predict the effect it will have on a complex, nonlinear system like the global climate.
Sure, maybe it will be fine. But the burden of proof should be on the people claiming that it's going to be fine, not on those recommending caution before screwing with something we don't understand.
That's a false dichotomy. There is no reason to believe that we can't have modern technology without catastrophic climate change. If for example we switched completely to nuclear energy and electric cars we would greatly reduce our carbon footprint to the point where the rest might be offset by planting trees and turning them into charcoal.
IF we did those things, sure. However there is significant pressure from various interests to stop us from doing those things on the basis that climate change won't really be a problem or that we'll fix it somehow if it is.
The assertion that climate change will result in human extinction is of course not literally true. But given our current path it is not a ridiculous hyperbole. The consequences we are talking about is the inability to grow food in much of the southwest United States, Mediterranean regions and large areas of mainland China. Not to mention the collapse of a healthy ocean ecosystem, storm variability, etc... This really is an event that will alter the way of life of everyone on Earth and kill a whole bunch in the process. It is not at all ridiculous to treat this as the existential crisis it is.
I agree that global warming is one of the biggest threats we face in the immediate future. I just dislike pointless hyperbole. The likely consequences are scary enough without having to exaggerate them. If we want honest discussions we need truth, not hyperbole.
In the strictest sense, no. But one difference, which might matter to some people, is that "ending it now" seems to imply actively killing people. Most people, I believe, would see that as inherently different from simply dying due to whatever interaction(s) happen with the natural environment around us.
All of that said, I'm not arguing against pursuing actions to protect the environment. Just pointing out that "preventing the extermination of the human race" really isn't a terribly good justification for doing so when you look at the big picture.
If you accept that premise, the question then becomes: "what are the good arguments for pursuing actions to protect the environment / reverse climate change?" That is, what arguments will persuade people to care about protecting the environment for future generations that don't exist yet, in a time beyond their own limited lifespan?
Which gadget do you feel is worth that?