Townsend will take up his new post at the end of this season despite being just 38 years of age and having never held a head coach role.
The 1997 Test Lion has worked as an assistant with the Scotland national side for the past three seasons after initially dipping his toes into coaching with Edinburgh and then Scotland A after retiring from the playing side of the sport five years ago but his promotion has been heavily questioned by critics.
"Let us judge me on what happens next season and not on what's just been announced. There is not one direct route to becoming a coach," said Townsend, who played in the first and second Tests when the Lions beat the Springboks 17 years ago.
"I have looked at colleagues and peers who have gone on to coach in England, such as Bryan Redpath and Carl Hogg at Gloucester, who came in as an assistant and, with Bryan, a head coach role just after playing rugby.
"When I retired from playing five years ago I was passionate about moving into coaching and I thought that it would be outside Scotland because that's where I thought the opportunities would lie. I was delighted and very grateful to be backed by Scottish rugby through working with Edinburgh initially and then Scotland 'A', and then the last three seasons with Scotland.
"My experiences of working with Scotland at the highest level have made me what I am today and I'm convinced that I will move this team forward."
Glasgow came second in their Heineken Cup group earlier this season, missing out on a place in the last eight to reigning champions Leinster but finishing above both Bath and Montpellier in Pool 3.
The Warriors currently sit fourth in the RaboDirect PRO12 and are on course for a place in the end-of-season play-offs for the second time in three years.
Townsend is confident he can build on the progress Glasgow have made under Lineen, with the ex fly-half targeting a regular place among Europe's elite as his ultimate ambition.
"My aim is to make Glasgow into one of the strongest teams in Europe and I think already the base is there," added Townsend.
"They have a tough group of players, are very tough to beat, and they are learners as well.
"I've been here a number of times working with Sean and I see this team as only going one place, and that's forward.
"I understand the responsibility of being a head coach. It is a privileged position I've been given and I'm very grateful to the union. I'll be working my socks off to make it a success."