There are three main ways to reduce damaging carbon dioxxide emissions:
Eat Locally

Try and eat seasonal foods, preferably grown locally. This not only reduces food miles, it encourages local rural communities

Eat More Vegetables

By eating more vegetables, you will eat less dairy and meat, all of which is better for your health and for the state of the planet.

Eat Organic

Organic produce uses much less artificial fertiliser. Nitrogen fertilsers, not only need a lot of energy to make, they are the single main contibutor in agriculture to greenhouse gases. Nitrous oxide given off by these fertilsers are 300X more potent than carbon dioxide.

And of course, you can eat less! Far too many people are fat or obese. While some may argue that this is a way to "sequestrate" carbon as fat, it represents a vast waste of resources.