To illustrate, I imagine that things would be a lot poorer without maritime shipping or railroads to transport goods.
I realize that certain things like tourism would suffer, but as a whole, how critical is air travel now that we have fax, e-mail, videoconferencing, etc.?
You are mixing the transfer of information vs. the transfer of goods and services. You are also relying on the assumption that the mere transfer of information is sufficient.
Sure, if your business relies solely on the transfer of electronic information you can be “successful.” But let’s take it down to the nitty gritty.
“Hey I can’t make it home for Mother’s Day. I’ll just make a quick toll-free phone call back to the hometown florist, order up a bouquet of flowers for Mom and pay by credit card. Better still if the florist has a web site, I’ll just do it all on the web.”
All electronic you say? For you, yes. But where do American florists obtain enough flowers for Mother’s Day? From Central and South America. Since flowers as a commodity spoil in a short period of time, forget the tramp steamers slowing moving northward loaded with flowers. They are shipped in by air.
So you kick back in your executive suite and have some fresh fruit as you cinch the deal with a client cross-country. That banana you’re eating did not travel by boat. It came by air. Same for the kiwi fruit. And that Alaskan King Crab dinner you had last night owes itself to air transport, too.
Oh, hell! Operations says a key router just went down and they have none in inventory (thanks to your “cost cutting” measures). A new one is ordered but by air it will take ten hours to get there. No choice you’ll pay a premium instead of a ground shipment, but can your business afford the downtime regardless?
And yes, despite the increase in electronic communications, people still prefer face to face contact. Call it cultural, common courtesy, or just that your mother wants to see you in the flesh once a year speaks volumes. Do you think it’s really possible to broker a peace deal between two warring parties via a video conference? 
Of course, bulk goods and commodities travel via truck, rail and ship. It’s not economically nor physically feasible to transport many goods via air (although the Berlin Airlift said it’s not impossible given the correct circumstances).
Step back and think of how many things travel by air, and not just tourists, business people and the occasional rich person’s fancy.
Catch my drift?
That’s an interesting question.
For starters, you have to remember that airplanes more more than just tourists.
Frieght operations such as UPS, FedEx, Airborne, and so forth simply can’t garauntee overnight, 2-day, or 3-day delivery without airplanes except in very limited geographic areas. Legal documents, as once example, must frequently still be sent on hardcopy still, so without these means of shipping there could be some disruption for those items that must travel in physical form. The US Post Office, by the way, is also heavily dependent on airplanes for moving mail over long distances, so mail delivery would slow down even more than present - it would be back to truck and rail for everything, not just some of it.
Some industries could survive without it, but it would be harder to get fresh fish and fresh-cut flowers and certain other very perishable items in winter in, say, Chicago or St. Paul.
Some places, like Alaska, Hawaii, and the Carribean no longer have the shipping capability they once had, or at least would require more than they presently have, in order to accomodate the needs of their populations without airplanes. Tibet, I believe, has airports but no railroads, so all frieght would revert to Yak-back and trucks. Loss of air travel would result in some very uncomfortable times, possibly even real hardship, until their economies adjust and shipping by sea and land can be increased.
Many businesses depend on air travel, either to move goods through the overnight services, or to move documents that must travel in material form, as well as moving personnel from place to place. Having employees drive themselves opens up legal liabilities companies don’t deal with at present, and we just don’t have efficient passenger rail in the US anymore. There would certainly be some disruption while people adjusted and this would be reflected in the bottom. Also, having had to switch some of my company’s meetings from face-to-face to videoconference, the technology is still expensive so you don’t always save money - you might even wind up paying more for remote meetings with participants in multiple locations. And the technology for that is still maturing.
One place where lack of air travel will have a life-or-death impact is in medicine. No air travel means no emergency airlifts. Since time is of the essence when medievac is used (the only way to justify the cost of those helicopters - they ain’t cheap) if it was eliminated probably more people would die en route to the hospital. Would also complicate wilderness search and rescue operations. In addition, transplant organs are transported by air (unless the weather makes flying impossible), as are certain other medical patients who need treatment at distant locations. In emergency situations, medical supplies can be shipped in by air to areas cut off by road (think earthquakes, floods, etc.) Without air travel likely more people would die in these circumstances than do presently.
No air travel will complicate forest fire fighting - we’ll lose more to the fires.
Not to mention that if you eliminate all air travel the air transit companies will all expire, rendering their stock worthless and causing havoc on Wall Street. You’ll have tens of thousands of unemployed professional pilots just in the US, plus all the service and support personnel - caterers, cleaners, security, ramp personnel, mechanics, ticket agents, etc. You can flush Boeing and Lockheed down the toilet - there’s not much left without airplanes. Not to mention other companies such as Piper, Cessna, Lycoming, Continental, Beechcraft, Robinson, Hughes… who employ not just pilots and mechanics but secrtaries and accounts and cleaning staff… all of whom would be unemployed.
I’m not sure how much impact it will have on the petroleum industry - I know the aviation gasoline is an insignificant part of their business, but they’ll be selling a LOT less jet fuel. It may impact their bottom lines.
There are an estimated 600,000+ active licensed pilots in the US. Even those such as myself, who do this for fun and not profit, help support every small airport across America, which adds up to over a thousand small businesses employing anywhere from just one or two to scores of employees. All of those people would be out of work.
Many hotels depend on air travel. Restaurants based on airports depend on transients. After Sept 11 the local corner diner near my home airport almost went under because 75% of their businesss comes from the airport (which they didn’t know until then).
No air travel means millions of people out of work due to the ripple effect air travel has on the economy. Probably 2-5 million directly involved with airports (all sizes) and airplanes (produce, maintenance, flying). Probably an equal number from the lodging, tourism, and restaurant industries. And, oh yes, the entire FAA and all those air traffic controllers. That’s just in the US. The world economy would survive, but you’d notice the difference. There would be a LOT of disruption until things adjusted to other means of getting around and all the unemployed aviation folks retrained for other jobs.
I’m not sure that answers your question, but they are all factors to consider.
You do realize that passenger planes also carry a huge amount of cargo including mail, person to person packages as well as business cargo on every flight don’t you? That whole system would be greatly disrupted. You might be able to replace some of the routes with cargo only planes a la Federal Express but I doubt the routes would be as frequent or as cheap to send cargo via air.
If you are asking what would happen if air cargo were not available either, then that would be a big freaking disaster. Perishable foods would only be available near where they were produced. Organ transplants could only go to someone geographically close to the donor. Geographically distant family members could only visit each other a few times in their lives.
Do you know something that we don’t? Tell us how big this ban on air travel is before we define the consequences.
As a employee of the Boeing Company, I feel that air travel is vital to the world economy and to my economy.
Come to Memphis and watch the FedEx planes coming in at night and realize that they will be turning around and leaving the within a few hours. It is very impressive.
“Perishable foods would only be available near where they were produced.”
Nonsense! Ships with refrigerated holds and trains with refrigerator cars not only CAN be used to ship perishables, they WERE used for the shipment of perishables before planes became big enough to carry large amounts of cargo, which IIRC wasn’t until after WWII. Meat and meat products processed in Chicago were consumed all over the world, and I’ve seen several early 20th Century photos of bananas being unloaded from trains in Northern cities.
Google the term “silk trains” and read some of the results before you presume that long-distance commerce in perishables arose only with the airplane. This ranks up with the oft-repeated (and IMHO equally irritating) canard that before Ford developed the mass-produced and affordable automobile, few people ever traveled more than 20 miles from home.
“Tell us how big this ban on air travel is before we define the consequences.”
Where does the OP mention a ban on air travel?!