I am wondering what the world would be like because in this story I am making, it is in the future where the ozone layer is gone and big cities have big structures that generate an artificial barrier to mimic the Ozone layer. There will be settlements outside of the major cities so I want to know what it would be like so I can change how the humans look, or how the humans live out there.
The Ozone layer provides two major effects.
Short wavelength filter. Ozone is quite effective at absorbing short wave, in particular Ultra Violet radiations (UVR). This is a provable relationship currently, the UVR striking the ground has an inverse relation with the size of the ozone layer (less ozone = more UVR hits earth). For humans, this is a skin cancer and sunburn threat. For plantlife...UVR tends to impair photosynthesis across several species of plants, including most of our big food stuff crops (rice, soybeans, winter wheat, cotton, and corn).
For changes to behaviour...first part is sun exposure has to be closer monitored and it will be significantly shorter before ones skin begins to burn. This of course comes with the skin cancer risks as UVR can cause some nasty cancers. People will be quicker to tan and people in high sunlight area's of the globe will likely have darker skin tones as the body tries to protect itself. Crops would likely be less yielding and it will take more land to feed the same number of people (kinda speculation as to how much extra though).
Ozone is a green house gas and has some atmospheric effects. Clear evenings could potentially be colder as the Ozone isn't there to trap heat in the same way and more would escape. This is going to have some weather effects...Ozone intercepts much of the UVR and in doing so heats up the upper atmosphere, in particular the thermosphere. Honestly I have no clue what reducing Ozone would do in this case...less active thermosphere maybe?
No clue on behaviour aspects here...temperatures may vary more heavily, especially in drier climates. More UVR striking the ground will warm it heavier during the day (and potentially increase humidity), while the evening sky will lack the ozone greenhouse effect and allow for additional cooling. There is the potential that sea surface temperatures will rise due to the additional heat from UVR, and if this is the case, tropical storms could become more powerful. Very speculative here.
The surface would be sterilized by ultraviolet radiation (UV-C specifically). UV-C destroys nucleic acids, damaging DNA and preventing cell replication and other basic functions. Atmospheric water vapour would absorb some UV-C, but not enough to protect life. A planet without an ozone layer would utterly lack life, from the simplest virus to the most complex organism, on its surface.
Life would exist underwater (and underground), as water absorbs UV-C within 50 metres.