1. If the warmth of 2005 killed them all, how did they get through the Medieval Warm Period?
2. If warming is so devastating to them, why were they allegedly so easy to find after the warm year of 1998 but prior to 2005?
3. As a rule of thumb, if we don't see an animal after only 20+ hours of spotlighting, can we safely declare it extinct?
4. Is it a complete coincidence that this story is being released at the same time as the climate meetings in Poznan?
One suggestion I have for our denialist friends is that they actually try and answer their own questions first, before trumpeting them into the echo chamber. But let's help them out.
#1. Typical laziness in denialists thinking they know something they don't - in this case, that Australia was warm during the "Medieval Warm Period." I've redirected the link in #1 above from a denialist site in the original to wikipedia - turns out we don't know what the temperatures were like in Australia. Equally important, a millenium ago the possums didn't have to deal with habitat loss from deforestation that they face now, where they can't survive in second-growth forests. Climate change is the follow-up punch that knocks out a species reeling from habitat destruction.
#2. More generalizing - while 1998 was warm in Australia (not that the denialists bothered to even look that up), the warmth "came from significantly warmer than usual minimum temperatures," when it's maximums that kill possums. This graph shows the really bad maximums for eastern Australia have been in the last seven years, and that 1998 wasn't bad at all (and what really counts anyway is temperatures in the much smaller highland region where the animals live).
#3. Twenty-plus hours of spotlighting over three years may not be enough to declare a species extinct, as seen by the fact that the scientists didn't declare it extinct, just that they were very worried and going back for another look. Going from seeing lots to seeing none in three years would qualify for being worrisome, I'd think.
#4. I expect they call that a news hook. Is there any coincidence in that Planet Gore is seeking to shoot down the story around the same time as the Poznan conference? The only difference is between doing science on one side, and incredulous, unresearched objections on the other.