Since 2019, the IPS has had its own fully-open document database. The database contains articles from IPS conference proceedings, policy papers and certain presentations and publications for which we hold copyrights. You can easily search the database by author, topic or year, for instance.
Try here: https://peatlands.org/publications/document-database
Additional content will be added by the Secretariat as time allows. The IPS headquarters in Jyväskylä also provide scans of older, printed proceedings on request.