Hi,
sdmsh is you friend here.
Use a select statement within sdmsh to select all your job definitions you want to change the environment on.
Example to select ALL jobs:
select
se.id as fullname
from
sci_c_scheduling_entity se
where
se.type = 'JOB'
with
fullname folder quoted; sdmsh allows the with option to translate the job definition id to a pathname (optionally quoted)
Add any joins and selections to get the list of your candidates to alter.
process the output of the select to generate sdmsh commands like:
alter job defintion <fullname from query> with environment = '<new environment name>'