How this works / Signed record

Problem revision

What lowered atmospheric $\mathrm{CO_2}$ by about $90\,\mathrm{ppm}$ in glacial times?

This record was signed by PubPhys and added to the public log. Download the record and check it with the open verifier: it recomputes every fingerprint, checks the PubPhys signature against the published key, finds the entry in the log and checks the Bitcoin date, without relying on this site.

Record hash
f95965742d9c7f4838a3a47b2517d1852aa39af502b7e327977b7078d5dfef45
Content hash
4d3a44ab995ffe05873662458fbd81928aff2e69bacd273525c300dd5862acdb
Signed by
c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da
Log entry
1,350
Checkpoint
Size 2,123, logged in Rekor and mirrored
Bitcoin date
Block 969,698
Created (claimed)
2026-10-03T07:18:03Z (the Bitcoin date is the one that counts)