Well first and foremost the Elites (Deep State-Illuminati) have technology and fortifications that remain hidden from sight and from speech by any one whom is not authorized. You might be surprised to know that the Elites do have Free Energy technology that they can survive off of underground in bases for more than 100 years if any type of Global scale extinction event occurs "they" are safe (Until God's seeks them out to be destroyed, in the coming future). They have the technology to grow entire forests and plantations underground (within logical reason, it's easily possible) for food, medicine and energy.
If Earth's atmosphere goes into a Global disaster type scenario, we can be sure the Elites will be Underground, not out and about breathing in toxins and pollutants (certainly not without some protective barrier around themselves, or breathing apparatus for air filtration, most remain hidden during sprays, ect).
Just think of CERN for instance, think of the technology involved, this is only the tech that they basically have to admit it's there because it's so large, but there are smaller technologies with unimaginable technology built into them that exist hidden, because they are in heavily fortified locations with heavy machinery and humanly impenetrable entrances and big brother technology from the sky downwards and that are heavy secured from sight, touch, mention or consciousness even without having the right authorization and DNA.
The Elites used to be Underground, but since gaining full blown power of humanity, they have dropped their shields and have started to become transparent, that's why many are confused, but the truth is now we are in new times, those old days of remaining hidden is no longer their prerogative. And it's because of the technology that they have now acquired through alchemy, science, technology, wisdom, knowledge, intellectual theft, and experimentation that they have now such ability to control mankind that they can now remain at peace with their secrets out in the open, nothing really matters to them anymore in this regard, and there is no fear being felt by them I assure you, how do I know this, because they have knowledge that is from outside of our Universe in their hands, and this gives them an advantage over the physical Earth because of this.