This truly is an intriguing concept. I've always wondered about the fact that history appears to repeat itself, because eventually we seem to forget what wars, pollution, and a general non-caring attitude can do.
It could also be much simpler; I don't think our current climate change is man-made. Humanity may have, in some small way, contributed to it, but I believe it's a natural cycle our planet goes through.
Be that as it may, any disaster, no matter what the cause, usually has a few survivors, and as long as there are survivors, the continuation of a species is guaranteed. Who knows what another 3 millennia will bring? Egypt could very well be a green and humid, almost Anglican looking landscape, and archaeologists will wonder how part of an apparent rock formation suddenly appears like a man-made pyramid; that is if all records are lost.
You have captured a potential future in a striking, but also in an almost sad, and moody kind of way. A time when humanity once again must learn anew all the technological marvels it once possessed; but also, that there is always light amidst the even darkest times.
While the overall concept of a dystopian future is nothing new (hence my impact rating), this particular concept I haven't seen before. Pyramids in conjunction with futuristic technology are no rarity, but to see Egypt in a setting like this, a pyramid enclosed in rock which has amassed over the many centuries, but to also still see it having survived as a monument to, by then, truly ancient times; that is a great vision indeed! And the overall quality of the piece cannot be faulted. I'd love to be able to point out some flaws to help, but I cannot find any.
Nicely done! Sehr gut!