So if a wall with a “carbon footprint close to Ireland’s annual CO2 emissions” keeps out just one more immigrant/year, your point “still stands” and it’s just a

So if a wall with a “carbon footprint close to Ireland’s annual CO2 emissions” keeps out just one more immigrant/year, your point “still stands” and it’s just a matter of “amortization time.” Your reasoning here is about as sound as your mischaracterization by a factor of five of the number of immigrants crossing illegally.