WHY is ocean acidification so dangerous? The question is tough to answer only because the list of reasons is so long. Depending on how tightly organisms are able to regulate their internal chemistry, acidification may affect such basic processes as metabolism, enzyme activity, and protein function. Because it will.

The paper concluded that if current emissions trends continue, within the next fifty years or so “all coral reefs will cease to grow and start to dissolve.

I like to think or say, some madness there.

If climate change drove the megafauna extinct, then this presents yet another reason to worry about what we are doing to global temperatures. If, on the other hand, people were to blame – and it seems increasingly likely that they were – then the import is almost more disturbing. It would mean that the current extinction event began all the way back in the middle of the last ice age. It would mean that man was a killer – to use the term of art an “overkiller” – pretty much right from the start.

What are the Chinese doing, what are we doing, what are – so we need, both the developed world and the developing world, really need to be moving, once again, getting all your arrows in the same direction if you want to have any impact.

As best as can be determined, the world is now warmer than it has been at any point in the last two millennia, and, if current trends continue, by the end of the century it will likely be hotter than at any point in the last two million years.

Under business as usual, by mid-century things are looking rather grim,” he told me a few hours after I had arrived at One Tree. We were sitting at a beat-up picnic table, looking out over the heartbreaking blue of the Coral Sea. The island’s large and boisterous population of terns was screaming in the background. Caldeira paused: “I mean, they’re looking grim already.

Beginnings, it’s said, are apt to be shadowy.

If warming were held to a minimum, the team estimated that between 22 and 31 percent of the species would be “committed to extinction” by 2050. If warming were to reach what was at that point considered a likely maximum – a figure that now looks too low – by the middle of this century, between 38 and 52 percent of the species would be fated to disappear.

LIKE the Jews, the corals of the Great Barrier Reef observe a lunar calendar.