you must weigh up the cost of insurance against the probability of the event and then decide.
would you like to pay a 10% tax to help me provide protection from aliens?
Australia is not a concern even if you believe in these rather lame and incomplete models used for predictions. and don't use the per capita argument without balancing it out with the per capita cost.
the article is stupid (as I expected) there is a difference in hitting a small area with that heat and the size of earth. more baseless and quite obvious scare-mongering. I guess they have no real bullets left.