and what do you make of this
The effects of an eruption that size might last five or six years. Your graph only shows three.
Show us a fifty year span with Krakatoa in the middle and then we'll talk.
5 or 6 years ? never.
50yrs ? no point talking with you, you make no sense.
Yes by 3 years the vast majority of the aerosol would be gone. A longer time period would however help with seeing the effects in context and compare it to other natural variability.
BTW I realise I reglected to respond to your point about Laki. Two rebuttals:
First, you're not considering the global or even hemispherical effects. Yes it's clear NW Europe was incredibly hot that summer. But there was also extreme cold to follow shortly afterwards in the USA and Europe. But instrument records are not comprehensive enough to draw conclusions about what Laki did to the global climate.
Second, Laki was far from your typical explosive eruption. For 8 months it spewed lava and sulphur containing gases into the troposphere forming a vast cloud of volcanic fog. Usually these tropospheric aerosols are washed out in days to weeks, but these were constantly replenished. It is theorised, but of course far from proved, that the nature of this smog in the stagnant weather pattern Europe had that summer contributed to the intense heat by absorbing solar radiation.
Meanwhile Laki also had several exlosive episodes capable of injecting sulphur into the stratosphere, where aersols have a longer lifetime. After the dissipation of the tropospheric haze this would have an effect over the next 2-3 years.