In truth, not a lot. 0.02g/C02e
You’d be better off driving 1 mile less than trying to tweet its carbon equivalent (about 32,500 tweets). So go ahead, tweet #carbonfeed.
The breakdown of 1 human breath ~ 2 tweets.
Normal C02 levels (Capnography) in a human are 35-45mmHG or 4.0-5.6% with each breath . The Tidal Volume (volume inhaled and exhaled during normal breathing) of an adult is 6-7mL/kg,  or roughly 400-500mL . We can then determine that the range of C02 per breath is between 16mL and 28mL. Using the molecular weight of C02 , we can determine that the weight of C02 in one human breath has the range of 0.02947 grams to 0.0515794 grams. With 1 tweet ~ 0.02g/C02e , then one breath is equivalent to between 1.5-2.5 tweets, or on average, 2 tweets.