From clausius theorem, we get

$dQ_2/T2 + dQ_1 /T1 ≤ 0$

$-∆S_{surrounding} - ∆S_{system} ≤ 0$

$∆S_{surrounding} + ∆S_{system} ≥ 0$

$∆S_{universe} ≥ 0$

It means, that entropy of the universe always increases. An attempt to decrease the entropy of a system will lead to infact an increase in the entropy of the universe.

This is also believed to be the reason that time always flow in one direction.