Our species in a very very short time has caused greater extinctions than nature ever could. Yes an asteroid or nuclear winter can cause greater harm than us changing the chemistry of the atmosphere and the oceans Ph, but this is no reason to not prevent this damage. Take a look at the rate rain forests and jungles are being clearcut for charcoal production and grazing land. I am not talking about era lengths of time, talking about as you stated, generations of man. There has to be a better way.
It takes more than a few thousand years to move a continent.
The island of Hawaii is less than 1 million years old and still volcanically active, while Kauai is about 5 million and Midway, far to the northeast, is 27 million. That is a long period of time between some fairly close islands created by existence over the same hot spot.
"Present-day Australia
Because of the movement of the plates, Gondwanaland gradually broke up. India, South America, Africa and Arabia started to separate at different times and fan out northwards.
About 90 million years ago a rift in the land started to develop between Australia (attached to what is now New Guinea) and Antarctica. By about 65-45 million years ago, the two areas were clearly separating, as Australia started its long drift northwards and Antarctica stayed almost stationary near the pole. By 35 million years ago the break was complete, and deep water separated the two continents."