Earlier quoted context omitted.
That's 2.6 * 10^8 cubic meters of compacted dirt and rock needed to raise the island by 10m-- which is more than 1500 kg/cubic meter (1.5 tonnes/cubic meter). The largest bulk carriers manage about 400,000 DWT. So, about 1000 trips of the largest around... ignoring the logistical and ecological challenges of procuring that much material and using it to raise the island in a durable way.
That actually seems pretty achievable since there’s centuries of time needed to raise 10m (assuming we keep on without any controls). I hope the math for how much it costs isn’t so low as to be sad to fix this problem in the wrong way.
But more importantly than the amount you need to raise the islands: 26 sq km * 1 meter probably doesn't raise the islands anywhere close to 1 meter, because of:
* Early losses from erosion and compaction
* The angle of repose around the islands (you can't just build the island straight up 1 meter).