Variable value from query

I know I can execute a query in a model and assign the result to a variable in this way:

{% if execute %}
{% set last_audit_id = run_query("SELECT LAST_AUDIT_ID FROM CFG.PAR_SCDM_AUDIT WHERE FLOW = ‘ORDER_MOVEMENT’ ").columns[0][0] %}
{% endif %}

but this variable is local to this model.
Is there a way to do the same thing in dbt_project.yml and thus feed a project-wide variable?
Thanks
Daniele