CO2 emission is automatically displayed on your flight result page, right next to the luggage allowance and travel policy compliance icon. For Low Cost providers (i.e. Ryanair or Wizzair) this value is shown automatically. For regular airlines you have to click the cloud icon to reveal carbon emission value for the flight.
You can see a list of your trips on the main dashboard. For more detailed view you can click “Bookings” on your dashboard’s left menu. Use filters on top for upcoming, ongoing, past trips, or different trip types (e.g., My Trips, Templates, Arranged by me).