What would happen next? Self-preservation would probably kick-in for most people: with the ultimate goal of trying to find ways to maintain air for long lengths of time. Life is a pretty big deal after all.
Some creative individuals would probably rig their home in a way to keep air trapped for at least a period of longer than 30 days and maybe even ways to maintain air for a year or so (if not longer).
Other individuals would probably just throw their hands up. Maybe with the belief that their savior is coming back to earth. Or faced with the beginning stages of apathy and grief.
Some more would react aggressively: violence and riots would likely spread throughout the world, followed with invasions and enslavement of groups of people.
Most would probably turn towards government: what are they going to do and how are they going to fix this?
Of course, the politicians would first turn towards blame, specifically trying to figure out the party whose at fault. They would go back and forth, emotions running at a fervor like never before.
At the same time, bi-partisan policy would shift towards protecting the ruling class - for example, by building multiple structures that can create and maintain air for decades or even centuries. They would likely save a few for the poor or middle class as a way to extend a olive branch.
Regardless, not everyone would have access to air. It would be impossible. There are only a limited amount of structures that could be created to "fix" the problem. And most of this would depend on who has access to those in power (i.e. Monopoly of force). Of course, politicians and top administrators would be protected. As would the wealthy and military members - after all, who is going to maintain order?
The poor - as they have throughout history - would mostly be left behind. Elites would publicly declare sadness for those without future access to air, while creating pathways for protection for friends and family.
Do you see this as handling out any differently? Is it unreasonable to expect that this course of events would occur?
if this series of events is reasonable, would it change if the length of time for the end of air was increased to 60 days, or 90 days, or even a year?
What is the difference with the system of governance we have today? Is everyone treated equally and fairly? Does everyone have equal access to the equivalent of "air" (I.e. Food, water, shelter, health services, etc.)? What about just plain old access?
Of course not. But that is why we have voluntary exchange. As a means of creating an environment where everyone has the ability to gain equal access to "air" or its equivalent. It's not perfect. Some individuals will have greater power.
But at least there isn't the ruse of a government that is there to provide for everyone - when, instead, it is only the ruling class and their friends who have the greatest access (there are exceptions of course).
Or is this just a wrong perspective? Too negative maybe? it's hard to imagine though. The wealthy and those in power don't have to worry about rising health insurance costs or drinking water with lead. They don't have to worry about going to jail for drug possession, fraud, or gross negligence that leads to the stunt of cognitive abilities in hundreds of children. But everyone else does.
And it's not the ruling class that will build the structures to contain air - but rather everyday people. Do you really think those everyday people will have access to those buildings? Yet, we should support more government?