Update CHANGELOG.md

CHANGELOG.md

@@ -12,7 +12,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 ### Changed
--Long names in State Spec files
+- Long names for carbon diagnostics to use BC, OC, and BR instead of CA.*
+  - Note this requires MAPL v2.35.3+R21C_v1.2.0 or later
+- Update `components.yaml` to match the `R21C` branch of GEOSgcm
 -Filepath for CEDS has been updated in the ExtData yaml and rc files. Note the old version had an incorrect seasonal cycle.
 
 ## v2.1.2+R21C_v1.0.1