[Truth666]

Glad aout your comment. I was hoping that there would be a palm and climate expert to contradict this.
In fact using the climate data for Lord Howe station, located at sea level, they could still manage a 5°C colder climate.
The problem is that howeas can't survive on their own at the small strip of Lord Howe stretching at sea level. They don't tolerate full sun until they are adult. Their habitat is the very special rainforest on the slopes of Mt. Lidgbird and Mt. Gower (in the picture, as most of the time, under the clouds), 500 m above sea level.
And if you it is still possible to debate if there 5°C cooler temperatures would mean extinction, you should not have any doubts that a change in the rain pattern would!

[dirtboy]

The problem is that howeas can't survive on their own at the small strip of Lord Howe stretching at sea level. They don't tolerate full sun until they are adult. Their habitat is the very special rainforest on the slopes of Mt. Lidgbird and Mt. Gower (in the picture, as most of the time, under the clouds), 500 m above sea level.

Really? A website on Lord Howe Island begs to differ:

http://www.lordhoweisland.info/environ/article1.html

These include four species of palm, the best known being Howea forsteriana, which forms dense lowland forests in some areas.So now both your palm and your coral theories are toast. Oh, well, back to the drawing board. Maybe you can play the Mississippi River gambit next time.

[dirtboy]

Their habitat is the very special rainforest on the slopes of Mt. Lidgbird and Mt. Gower (in the picture, as most of the time, under the clouds), 500 m above sea level.

Hmmm - Mt. Gower is 900 m high. Here's a picture:

Looks like the top 400 meters are almost vertical. Yet this is the "rain forest" you are talking about?

[Cobra Scott]

So all you've done is present evidence that both the flora and the fauna of this microcosm has actually had to evolve (via natural selection) to weather these climate changes that you insist on. Unless these changes and their effects are not the only viable scenario...