Got a source for your numbers?
According to the numbers you provided....If the median African American IQ is 90 then 50% of that population is within 80 to 100 IQ, 16% would be 105 or higher and 3% would be 115 IQ or higher.
If the median Jewish or East Asian IQ is 110 then 50% are within 100 to 120 IQ, 16% would be 125 or higher and 3% would be 135 or higher.
If environmental factors account for 60% of that discrepancy then how would it be a social disaster to attempt to ameliorate those environmental factors?
If those factors could be changed completely and African Americans raised like Asians and Jews (which is of course unrealistic) the median African American IQ could be raised to 102, which is a couple points higher than the Euro American average.
Second, environmental factors account for 60% but that is broken down to 10% which cannot be adjusted (fetal environment, chance occurrences, etc.), 50% which can.
Third as I point out, and you concur, those factors cannot be completely changed. I estimate that we reduce the difference by a quarter to a half- which translates to 3-7 points, to 88-92. [the total difference is 25 points. Half of that is 12.5 points. 25-50% of that is 3-7 points, roughly]
These are rough estimates. You can easily adjust them to suit yourself. But anyway you cut it no more than 15% of blacks will have IQs above 110, almost none above 125, which is what's needed to work in the world of high-end jobs if merit is the measure.
That's a social disaster. Everyone will notice.