This is why it is a bad idea to make the planet hotter than it has been in the last fifteen million years. We don't know what might happen.
The demise of the world's forests some 250 million years ago likely was accelerated by aggressive tree-killing fungi triggered by global climate change, according to a new study by a University of California, Berkeley, scientist and her Dutch and British colleagues.
The researchers do not rule out the possibility that today's changing climate could cause a similar increase in pathogenic soil bacteria that could devastate forests already stressed by a warming climate and pollution.
Are these scientists right about the role of these fungi in the Permian mass extinction? Maybe. Will warming now produce a similar outbreak? Hard to say. Would a massive die-off in the world's forests hurt us? Let me count the ways. Habitat loss. Watershed damage. Loss of agricultural productivity, including lumber. Loss of a major carbon sink, with accelerated CO2 accumulation in the atmosphere. Worsening fires (dead things burn.) And so on.
This is the sort of story that makes deniers see red -- no one can tell them, with certainty, what will happen (which they think is what "real science" does) and so this in contrast is hyperventilating alarmist nonsense, apocalyptic thinking, doomsday paranoia.
I don't think that it is. No one is in a panic; no one is promising that the seas will evaporate and the moon will be as blood. It's just a matter of simple, practical reality that if you keep rolling dice, eventually they will come up snake eyes. We have a limited understanding of our climate, we have never in the history of mankind seen warming like this, and the farther we progress down this unknown path, the greater our likelihood of something like this -- a previously unexpected interaction of biology and climate that will violently shift our ecology into a less friendly set of operating parameters.