If you ever see one of those thought experiments wherein ‘If physics property XXX changes by 1%, what would happen?’ the answer is: within 24 hours, the overwhelming majority of humanity would die.
That’s not to say everyone would. Unless it’s something cosmological like the gravitational coefficient, some people would probably live. Further, after a while, things would stabilize and those people would probably find a way to keep living. But in the short term, one day to one week? 99% of all people dead.