Scan it...
...and save it for posterity. Granted you better have a "fast" scanner so you can finish the job over a few months in your spare time.
Then you can print yourself up a facsimile and put the original in a place where it's out of harms way...or...you can use the original until its pages fall out, the spine flaps in the breeze and the covers have some dozen well earned coffee rings...and not feel guilty about it.
;-)