When I lived in Adelaide, each winter the books in my room would develop a gentle ripple through their respective text blocks.
Adelaide is not known for being damp – quite the contrary, in summer the sun blasts everything and the relative humidity can plummet to the single digits. But winter is Adelaide’s wet season, such as it is, and I lived in an un-insulated stone and plaster house that wicked up cold and damp and then emitted it again like slow-release fertilizer.
Damp makes cold feel colder. Cold temperatures tend to make the air damper. It was a vicious cycle. On some mornings I would open the fridge and feel certain it was warmer in there than it was in the kitchen. I cursed our forebears, for their failure to build properly environment-proof structures, and our landlord, who apparently felt no duty of care towards the welfare of her tenants (or their books).
When spring arrived and the dampness disappeared, the ripple would gradually disappear.
Paper curls and distorts when it gets damp because the structure of paper fibres physically expands. Many organic materials do the same thing — it’s why your wooden windows and doors stick in wet weather. The expansion and contraction of book structures is not necessarily a disaster, but it does place physical strain on the book. Some books will not return to their pre-dampness shape, as mine did, remaining permanently distorted.
Dampness also accelerates all sorts of other things. Mould loves damp. (There were signs of mould growth in the laundry and on the ceiling of one bedroom but I never found mould growing on my books, fortunately). Silverfish love damp. Chemical reactions occur at a faster rate when it is damp. Dust is more likely to stick and settle to surfaces.
And when it’s cold and damp, young women are more likely to shed tears of despair onto the page.
(When it’s warm and damp, gin and tonic disasters are more prevalent.*)
*This claim has not been substantiated by any peer-reviewed literature