Next up we have the CO2 impact that this travel gives, a quick swipe right from the first screen gets you here. Measured in metric tones this is the CO2 emissions from your travel. Again this is 'time since the start of' the day, week, month, year and you can see higher values for the week than the month depending on when the month starts.
The second column includes a calculation of the number of trees required to offset that CO2 within the same time period this isn't the number of trees you'd have to plant which over the course of 100 years would offset your CO2 emissions but instead is the number of trees it would take to actually make you carbon neutral within that day/week/month/year. You'll notice here that the offset figure for 'total' is probably higher at first than the figure for year. This is because the year is calculated from Jan 1st but the total is calculated from the first point that was tracked. This means that unless you install this on Jan 1st then for the first year the total tree offset will be higher than the year offset.
The use of the Trees for the same time period has been used as this is what it takes to be actually carbon neutral, carbon deferred for 100 years will still have an impact today.