K.H.
I wish you the best of luck!!!! My daughter (now 3 1/2) began climbing before she could walk. She started climbing at about 8 mos, yet didn't walk until 15 mos. Go figure!!! I know the stress - when she was about 1, she climbed my entertainment center like she was King Kong and fell with her mouth open and her 2 front teeth wound up pushed back into her gums. I actually thought her teeth were knocked out until I looked closer!! This happened when I dared to pee!!!
She still climbs everything. Time out does work, but the playpen never worked for me - she climbed out!!! Now she climbs the gates like it's nothing. I swear she is part monkey. Just try and make everything as safe as possible and work on time out. Oh, and walk away from tantrums. Once he realizes they have no effect, he'll stop. Good luck!!!