Look at the sky - what do you see? The Sun. The Sun is source of all life - without Sun I wouldn't be here to write on a blog. You will have to agree that the Sun is an infinite source of energy. Our planet Earth came with an infinite battery pack.
I understand that we humans are currently using non-renewables such as oil and coal to power most of our stuff. But I have belief in human ingenuity. I believe that once we run out of oil, coal, and maybe other stuff we could burn in an extremely crude, messy, and inefficient process, we'll find new sources of Energy. And the fact that the Sun is there means that there is no limit that nature placed on us. Limits that we may find are merely in our minds, and so, can be overcome.
I find this reassuring.
I don't think it should be an excuse to destroy our environment. To the contrary, preserving or, rather, finding a way to co-exist with other life on this planet is critical to our survival as a human race. But it's not just survival that we aim for - it's much more. I see it as reassuring that the only thing that can wipe us humans off the earth, the only thing, even, that stands between us and eternal bliss, is us. Nothing and nobody else prevents us.