The world, oceans and surface, have been warming because of us humans. Cycles like La Nina and El Nino bring variability to the weather around an ever warming planet. La Nina cools while El Nino warms. So it's likely that we will break all time heat records (you see that already in Texas for example) and that means more dead people. We may even temporarily go above 1.5C, providing a nice preview of what "normal" will look like in a couple years time (well, there is no longer a normal, expect warming and chaos).