All carbon transgressions, no matter if perceived as trivial or insignificant by another, can deeply impinge the transgressor, and create great suffering. There is no order of difficulty with eco-guilt: one person's pound of carbon is another's metric ton.  The Carbon Confessor accepts all, hears all and holds all confessions as equal.

Sample sins:

Dear CC, I could have walked to meet you yesterday for coffee.
I mean, I only live 4 blocks away from the cafe, but I drove instead. I feel horrible about that.
-Sad in San Rafael

Carbon Confessor, I have eaten meat my entire life.
I eat meat at least a few times a week, if not every day. We're talking good prime rib
and juicy hamburgers.  I now hear that  raising cattle and meat production play a huge
and devastating role in environmental degradation. But, I like my burgers! Thanks for listening.
-Hungry in Houston

Forgive me CC, for I am about to carbon sin. 
On Sunday I will fly to Atlanta, by way of Phoenix, to explain to government officials how
bacteria eat natural gas. Today I sought to pre-absolve my own carbon sins by opting
to cycle to work in a rare but major down poor.  The deluge through which I traveled did
not wash away my carbon sins, in fact quite the opposite.  When I arrived I was sufficiently
cold and wet that I had to turn up my gas powered heater.  I am now turning to carbon
comfort food, and will soon eat a Mango delivered recently from South America.  I can almost
taste the heavy fuel oil used to propel that Mango to our shores.
-With best carbon wishes,
Carbon-Guilty in Goleta