We've already blown past critical 1.5 C climate threshold, sea sponge study claims. Should we believe it?

I don't believe the 2º C over pre-industrial times average temperatures limit will be crossed before 2030, I guess it has been already crossed.

For its more immediate and more economy devastating consequences, I suggest reading: 'Sea Changes', Science, 2015.

About health issues, I won't trust much the WHO, it took several weeks for them to realize COVID is a respiratory disease, and Respiratory Isolation measures, direct and inverse, had to be implemented.
Vaccines for a new disease do not come in one day.
Blessings +
Sea-level rise due to polar ice-sheet mass loss during past warm periods