However, did it really cause changes to the regional/European climate in
the years 1783, 1784 etc?

Yes,see
http://www.cosis.net/abstracts/EGU04...04-J-05244.pdf
and
Atmospheric impact of the 1783-1784 Laki Eruption: Part II Climatic effect of sulphate aerosol
E. J. Highwood and D. S. Stevenson
ACP V3 Page(s) 1177-1189. SRef-ID: 1680-7324/acp/2003-3-1177
freely available at
http://www.cosis.net/members/journal...j_id=2&i_id=28


--
regards,
david
(add 17 to waghorne to reply)