In The Walking Dead, Rick Grimes wakes up after a coma caused by a serious injury incurred in the line of duty to find that his entire world has changed. Towns are populated by the living dead. There are no functional remnants of society--no grocery stores still supplied by trucks, no electric power, no gas tankers fueling up tanks at Chevron so the parade of happy motoring can continue. There are no cell phone bills to pay, no insurance agents to call, no IRS agent left to collect on unpaid taxes. The world is changed irrevocably practically overnight.
For many folks, this kind of apocalyptic fast collapse is the fantasy land they dream about. It's worth dreaming about, despite the horror, because if it happens it means that there will be no more bills to pay. The grind of daily life will suddenly be replaced with a more visceral struggle for survival. Life will suddenly have meaning: Protect yourself and your loved ones at all costs. For many caught up in the chronic stress most of us experience daily in developed nations, trading chronic stress for periods of acute stress sounds like a welcome relief.
Unfortunately, that's not how industrial civilization is going to collapse. It will collapse in bits and nibbles, over time, and people will experience chronic stress daily, punctuated by acute stress, followed by more chronic stress as they deal with the fall out of whatever caused that acute stress.
There are multiple examples of natural disasters in the US right now running riot over anything puny human hands have tried to create to keep them in check--be that actual physical structures, or legal or political structures.
Example: Hurricane Harvey just flattened Houston and surrounding areas, doing significant damage to oil refinery infrastructure, which is still not fully online. Many homeowners in this part of the world did not carry flood insurance, and so in the aftermath of the waters that have inundated their homes they are left with the choice of tearing out rotting drywall and rebuilding, or giving up their mortgages and moving (possibly declaring bankruptcy in the process).
But a hurricane is not the end of industrial civilization as we know it. The US, particularly the south, weathers hurricanes each and every year, and sometimes their intensity is ferocious and awe inspiring and causes floods and fires and deaths and property damage, some of it persisting for years.
Example: Fires have been raging in Los Angeles. Seven hundred people have been evacuated. 7,194 acres have burned. Los Angeles sent 100 firefighters to help with Harvey recovery efforts; in the sway of their own disaster they were forced to recall those emergency personnel. How many of you want to bet that Houston will be able to send aid to LA, if needed?
Example: A group of teenagers allegedly set off some fireworks that has kick-started a blaze in the Gorge in Oregon. We're on day 5 of that fire right now; it is 5% contained. 33,382 acres have burned and 1,865 residents have been evacuated. Ash is falling on my backyard patio furniture. Yesterday I farmed while wearing a type 95 painter's mask because of the particulate matter in the air. There are an additional 500,000 acres burning in other places in Oregon. The only upside is that all the ash in the air has lowered the temperature to tolerable from what was supposed to be several scorching hot days. Oregon Governor Kate Brown has asked for federal assistance and been denied.
But you know what? Industrial civilization doesn't end because of forest fires, either. Humans have used fire and fled from fire since almost the beginning of our existence as a species on this planet. It's going to rain, and if man-made efforts aren't able to put the fires out, the deluge of fall storms typical in the Pacific Northwest will do it. Some people will have to evacuate; so far no one has lost their home. Many will move back after the fires are out and continue living their lives, property damage or not.
Example: Hurricane Irma has slammed into Puerto Rico and the Dominican Republic leaving devastation in its wake. 95% of all buildings in these already poor and struggling areas have been flattened and multiple deaths have been reported on various islands in the Atlantic. Irma is about to smash into Florida as one of the most powerful Atlantic storms ever recorded. Friends of mine have made Facebook posts explaining the now logistical impossibility (gas shortages--partially caused by aforementioned thrashing of Houston refineries) of them evacuating and their decisions to weather out the storm in place. But, small blessings--it's probably not going to hit Houston.
Even so, a second major hurricane--even one that hit Houston--would not cause the end of industrial civilization. Many of the people in the path of Irma, if they survive, will rebuild their homes or, if they can't, they'll move elsewhere and start their lives anew. Some people, those on the very edge of ability to participate in modern society as taxpayers and consumers, will stop being able to. If they have no family support system they'll end up homeless or dead, a few years down the road. But the vast majority of people will have somewhere they can go, someone who will take them in, and will receive some kind of state or federal assistance (until federal assistance is no longer available, anyway).
As I don't watch any major television news, there may be several other major natural disasters happening in the US right now of which I am completely unaware. I don't mean to slight the folks experiencing them by not including any other fires, hurricanes, floods, avalanches, or invasions of body snatchers. You are worthy of attention too.
Industrial civilization ends in bits and nibbles, over some decades or perhaps a century. We are experiencing the beginning of the end right now. Multiple states are experiencing significant crises caused by natural disasters (made worse from climate change). Multiple states are throwing all of the resources they can at the problems they are facing. Multiple states have called out their National Guard to support disaster relief efforts. Multiple states are drawing on the resources--official or not--of other states around them to provide relief to their impacted populations. Multiple states are appealing to the federal government for financial or logistical assistance.
What happens when, instead of three states with serious and ongoing co-occurring natural disasters that impact major national infrastructure and cause property damage and loss of life, there are five states? Seven? Fifteen? At what point does a combined crop failure from drought in California, a Hurricane along the east coast that hits NYC and causes a sustained power outage in Manhattan, a raging fire in Colorado that threatens the Dillon Dam (which provides water for Denver, the capitol of Colorado and a city home to more than 650,000 people), and a major flood in Houston caused by torrential rains that impact our oil refineries begin to become an insurmountable problem to solve? How many displaced people (read: climate refugees) can the US handle at once? How much money does FEMA have to spread around to multiple disasters? What becomes prioritized in the aftermath of multiple major disasters, and what gets left behind--the locals told they must fend for themselves, no help is coming?
The federal government, and to a similar extent, state governments, will have to prioritize what can actually be saved and what is worth saving. Some people will be left behind. More and more people, towns, cities, entire states, in fact, will be left behind after a disaster over the coming decades. Any rebuilding or relief that comes will depend on local communities only. Slowly, what makes the US a juggernaut around the globe will whither as she has to spend increased attention and resources on national problems. Some places will recover, or will be unaffected. Some places will be fine. Other places will not, and they'll collapse back to whatever energy usage local resources can support--in most places, that will be human and animal power.
In 2011, 1.65 million US households were living on less than $2/day, according to one researcher (others disagree, of course, on how many people are in poverty, and results might depend on where the researcher receives their funding). That monetary figure is what many researchers and organizations use to define global poverty. It's a label applied to developing nations. How many millions in the US (we have a population of about 326 million) need to fall under that 2$/day figure for the US to sink from its exalted status as a developed nation? How many people need to be living on the streets, depending on food banks or soup kitchens, for the US to be considered a third world country?