How would world look like if deserts spread all over it?
There would always be air (atmosphere) but not necessarily in a balance to our liking (e.g. c.20% O2). That said, I don’t think there would be a huge shift in atmospheric gases (certainly not in the short- or medium-term) as there are many forms of marine life that wotrk on photosyntheis and exhale O2 – these would still survive. ‘Deserts’ and ‘sand-like deserts’ are not the same thing (you seem to be considering them synoymous hence asking about eternal summer). A desert is an area of very little rainfall and very little life. The polar regions are desert hence a world covered in deserts could be a ‘snowball Earth’ in the grips of an ice age colder than any seen before as much as a hot ‘Planet Dune’ place. In fact, a frigid desert is more likely than a sand desert as the hot, sandy desert requires: a) Sand (it will take quite a few millenia to erode enough rock for that) and, more importantly; b) Heat. The only mechanism we know of at present for the Earth to become that hot is throug
