If an estimate is say 20 - 80 years and 70 years turns out to be correct, are you going to dismiss the science because someone used 20 years in an attempt to get the message across? It might escalate due to some unforeseen factor and be less than that, another factor might extend the life or change what is there into something else.
What is important is to do something to reverse what is happening because there is overwhelming evidence that the Great Barrier Reef is in serious trouble.
