Why I Don’t Like the 32 psi Tire Pressure

I have been used to driving around with 38-40 psi tire pressure since I got my 2012 Kia Rio SX.  It came with the default Hankook tires  with a max value of 44 psi.  Lately, I got new Michelin tires installed by COSTCO.  I did not realize the technician set all tires to the standard 32 psi.  Most dealerships and repair shops set car tires to this value.
And this is what I got on the CO2 emissions graph – a spike up.  So I set it back to 38 psi  and the values trended down again.