Ukraine MOD has a program in place that databases every cluster munition fire mission. Demining eastern Ukraine is going to be a years long effort. Any unexpended ordinance will go into that effort. Countries that gave up cluster munitions have had their rose tinted glasses on too long and assumed war would be limited to foreign battlefields and not their back yards.

Typically, volcanic eruptions have a cooling effect. One of the principle emissions is sulfur dioxide which reflects high frequency solar energy (green house gases absorb and convert that same radiation into longer wave energy which excites atmospheric gases).

You can read more at the University Corporation for Atmospheric Research.