Ok.Most of the answers are, we will be fine, we will find something else, I am guessing those who are arguing this are not professionals working in the field.
True, but some of us have looked at what professionals working in the relevant fields are saying.
The issue isn't running out of things per se. It's the increase in costs of acquiring them. What's running out isn't the materials, it's the more easily obtained materials. If you have to dig deeper or do more complex processing of raw materials to extract the required materials, it's more expensive.
On the other hand, improvements in technology can reduce the requirement for the more expensive materials. Take batteries as an example. There are advanced prototypes of lithium-based batteries that use far less lithium. They may well be commericially viable within 5 years. There are experimental results indicating the possibility of making batteries solely from very common materials. In other words, there's a strong possibility of a continuing decrease in the requirements for finite materials that are becoming more expensive as the easily obtained deposits are used up.
On another hand (all hold hands together, kumbaya!), improvements in technology can make extracting the required materials less expensive, thus making new deposits viable. We've seen this already - for example, many current oil wells wouldn't have been viable in the past. Deep water wells would have been impossible 100 years ago and ruinously expensive 50 years ago. Now they're common. The process continues. The most high-profile example is asteroid mining. There are huge mineral resources in asteroids. It's just about possible to mine an asteroid now, but it would be ruinously expensive. With improvements in technology, in decades to come it might become viable, like deep water oil wells.
On yet another hand, improvements in technology can replace some use of finite resources with much less finite resources. Nuclear fusion, for example, would dramatically reduce the need for more finite resources for power generation, replacing it with a need for hydrogen and simultaneously providing a way of easily obtaining hydrogen from a very plentiful resource - water. Fusion can easily provide such a superabundance of electricity that it would become viable to use loads of it to split water into hydrogen and oxygen to provide hydrogen for the fusion. It's also possible that improvements in technology will result in more efficient means of obtaining pure hydrogen - there are a variety of methods in the experimental stage at the moment. Then there are other methods of using much less finite resources to reduce the need to use more finite resources, all lumped together as "renewables". Some of them are already viable in some parts of the world (e.g. CSP is technologically viable in hot deserts, geothermal is viable in highly volcanic areas such as Iceland, etc) and improvements in technology will probably make more of them viable in more areas.
The question is which way the balance will tip - needed resources becoming too expensive or the expense being offset by the collection of other hands I describe above. Given the inventiveness of humanity, I think it'll tip the right way, into those hands. Humans are collectively very good at cobbling solutions together when it's really needed (and collectively rather bad at doing so in a planned way before).
Predictions seem to be usually off. But our resources are finite, of that most people wouldn't argue, unless of course something supernatural happens. So the mentality is, 'we will be fine for the next few years/decades so who cares'.
True on the whole, but thank goodness for scientists and engineers. "How does that work?" and "How can we make that work for us?" are the questions that will solve the problems for a lot longer than a few years or decades.
Fusion, for example, would provide an abundance of electricity until the end of the Earth. That's a lot longer than a few years or decades.
Nowadays, replace "supernatural" with "graphene"
But in reality there is no way to replace the efficiency of crude oil, maybe some ways to produce energy via Geo-Environmental resources, but no real way to replicate the plastics and all the chemicals we use that are distilled from oil in any efficient manner(respective to crude oil).
That is a genuine problem, but reducing the need to burn oil for energy would extend the useful lifespan of oil for the numerous other uses it's put to. Replacements are being worked on and that extra time makes it more likely that viable replacements would be found.
Point I am making is, finite + constant increasing demand does not equate and something has to give. Maybe I should join the green party.
Yes, something has to give. We can either bin civilisation, kill most people and have the remaining relatively few people live a stone age life or we can seek a solution through knowledge and practical implementation of that knowledge - science and engineering.
Come to think of it, even stone age life is partially dependent on finite resources. Stone tools and weapons wear quite quickly and there's a quite small finite supply of suitable stone that can be obtained with stone age technology.
Science and engineering is the only viable solution.
