[Mr Ramsbotham]

This is a good reason not to climb mountains in Japan, especially without a large caliber firearm.

Or a heavy club to beat them off with.

[Dr. Franklin]

Or a heavy club to beat them off with.

Here's a video from a guy with a GoPro camera on while suddenly attacked by a black bear in Japan while climbing:
https://www.youtube.com/watch?v=R2KEWofvmss
See how suddenly the attack comes. Imagine if this were a brown bear. Climbers try to keep their equipment light, so they avoid heavy weapons. Bears and bear attacks are increasing in Japan. Climbing mountains in their territory isn't wise, because the humans are at a disadvantage if attacked.