With respect to Mr Kochanski's bear club and road flare advice, it strikes me as a bit unrealistic. He says with great pride that in 40 years of life in the bush, he's never carried a rifle. To me that smacks of an ideology rather than as evidence that an alternate choice to a firearm makes you any safer. That said, the individual who has never held a gun, can't be expected to defend himself with one; "You are no more armed by owning a gun than you are a musician by owning a piano." But more on that later. Then there's the good old you're more likely to die in a car wreck on a highway than you are in a bear attack. Well, that holds true only during the time that you are actually in the motor vehicle, once you're on foot in bear country, and the highway is out of sight, the percentages change.
There's a big difference between surviving a bear attack and walking away uninjured from a dangerous bear encounter, which would you prefer? A firearm is designed to stop a lethal threat from a distance, before it can hurt you, whereas if you are armed with only a club, then by definition, the threat is close enough to make contact. A road flare used as a weapon, in a stressful dangerous bear encounter, is a forest fire waiting to happen. Why would you put yourself in either of those situations? But should your personality, and physical prowess bring you to prefer a club to a gun, rather than something the size of the Roman Gladius, consider the advantage of a hardwood pick handle, or better yet a 6' staff, which can at least aid you in walking, and gives you greater separation from the threat, when its used as a thrusting weapon. The use of a club or staff in combat also requires a degree of knowledge, so if you happen to be an expert in Eastern martial arts which have a weapon component, you're possibly in good shape. But a very brave local fellow here, armed with a club of sorts, a snow shovel actually, attempted to stop a polar bear attack on a young woman, just a short distance from my house. He succeeded in drawing the bear away from it's victim, but the surgery he required, after being life flighted to Winnipeg, was less than enjoyable, so I don't recommend clubs as viable bear defense tools. The bear, a small one, was subsequently driven away with a truck and shot a short time later.
Machinery exists to make our lives more convenient and safer. Firearms are are a type of machinery which fill a particular niche, and require some esoteric knowledge to use effectively. A measure of competence can be realized in a short period of time, provided good instruction is received. Once you are confident and competent with a firearm, it provides a number of advantages over it's nonlethal alternatives, not the least of which is the confidence a firearm inspires, allowing you to make good panic free decisions. Secondly, it allows you to influence events from a distance, and this is the primary advantage that the firearm brings to the table. If you're alert to the bear's presence, the firearm effectively prevents him from being able to get close enough to touch you, and if he can't touch you, he can't hurt you.
The firearm remains useful for as long as your ammunition holds out, whereas pepper spray is depleted very rapidly, and then you are unarmed, while your threat is still in the immediate area. A shotgun can be used as a scare devise with the appropriate less lethal ammunition. Its been my experience that some bears don't respond in a positive fashion to live fire when its used in an attempt to drive them away, but they all respond in a positive manner to cracker shells and rubber bullets when fired from a shotgun, provided they have an avenue of escape. The transition from scare cartridge to lethal fire can be made rapidly with a bit of training and proper ammunition management. While I personally prefer a rifle, though not near populated areas, a rifle usually has no alternative to lethal fire, and if you're tempted to use rifle fire to scare the bear away, do so knowing that your magazine capacity is being depleted, and the result might not prove beneficial.