Preparing for this walk I realised that people were walking literally eveywhere. I was particularly humbled by the accomplishments of Owen Martel, Andrew Temill, Patrick Leigh, Christine, John Hayes, Karl Bushby and, of course, Ed Stafford.
For the similarity of our starting and end point, if not for the route taken, I have to mention the incredible journey of Jan Balster (unfortunately only available in German) who walked 3100 kilometres from Dresden to Dublin. With no money. And a banjo.
In contrast to these modern day feats of long-distance travel, I highly recommend 'A World to See: How a Blind Man Became History's Greatest Traveller', Jason Robert's biography of 19th century blind traveller James Holman (1786–1857).
My calculations on carbon emissions were based on the following sources.
Private car emissions - 2011 EU Fleet average: 135.7g/passenger/km http://ec.europa.eu/clima/policies/transport/vehicles/index_en.htm
Bus emissions - Bus Eireann Regional Engineer Gordon Bryan in private email: 67.33g/passenger/km
This number is based on *average* occupancy which is much lower than peak time occupancy. For comparison, DEFRA calculated the average occupancy on all city buses and coaches in the UK in 2008 as 9.2 passengers and 89g/p/km. http://archive.defra.gov.uk/environment/business/reporting/pdf/passenger-transport.pdf. As any regular bus passenger can attest, occupancy rates at peak times are usually a lot higher.
Flight emissions (excluding the trip to and from the airport) - Dublin-Berlin 1315km->225.4kg x 6 = 1352.4kg