I do not "wear a hat" that fits any belief. I do know that many forms of life developed and then became extinct, long before mankind appeared on the planet. This is knowledge from known facts discovered over may years of study. Even the human race developed from a subform; reference latest findings currently being reported in the media.
And many previous species became extinct through the changing forces of nature; now mankind is ultimately going to be faced with changes that could result in extinction and, if the global-warming pundits are really to be believed, mankind is on the road to hepling nature do just that.
There is another problem with this global warming argument. No single person has the expertise to study every aspect of what is happening to the planet; the overall opinion, if there is one, is an assembly of different study groups with expertise limited to their own fields. Still further, many of these groups also have differing opinions within their own spheres of knowledge so, when putting together an explanation of just what is happening (or going to happen) we will have several permutations, depending on who talks to whom.
Anyone who claims to have a precise knowledge of what the future of the planet holds for everyone who will be on it in, say, 500 years time is simply deluding themselves.
The Earth is around 4,500 billion years old, and went through many changes before Mankind appeared, some 3 million years ago. Earth is now roughly half way through its life, and I would bet that it has many more phases to go through before the end; and mankind is just as vulnerable as were the dinosaurs.
It makes sense for mankind to take steps to carefully manage the planet's irreplacable resources, and there are many other elements apart from fossil fuels that are necessary for survival, and all of them do not have renewable alternatives.
The problem is going to be able to get all the governments of different countries to work together with a single aim. That hasn't happened yet, and is not likely to happen in the future. Despite us being aware that we already need to act, governments are pulling further away from each other; not even trying to pull together with the determination crucial to the prolonging of an environment that can support life as we understand it.
And that is the rub; prolonging it, because nobody knows what is really in store in the future mists of time.